JPH0746533A - Recording device for digital image signal - Google Patents

Abstract

PURPOSE:To provide the recording device which can reproduce moving images with high picture quality and smooth movement on the reproducing side by recording digital image signal as a little information quantity as much as possible. CONSTITUTION:An input digital image signal is previously divided into the still picture information of a background image and the information of a mobile object to move on this background image. The still picture information of the background image is stored in a memory 23 BG. The background image is separated from the input digital image signal, and the change information of this separated background still picture corresponding to the background image in the memory 23 BG is calculated. A recording medium 11 records the still picture information of the memory 23 BG, the change information and the information of the mobile object. The still picture information of the memory 23 BG is updated based on the change information. Signals recorded in the recording medium 11 are reproduced, and the change information is reformed by using the still picture information in the updated memory 23 BG. The recording medium 11 records again the still picture information updated in the memory 23 BG, the reformed change information and the information of the mobile object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital image signal recording apparatus capable of recording at a low bit rate.

[0002]

2. Description of the Related Art Digital image data of a moving image contains a very large amount of information, and if it is transmitted as it is, the transmission bit rate becomes very high.
Therefore, when recording is performed using a low-rate recording medium whose transmission bit rate is limited, such as recording and reproducing digital image data using a magnetic tape or a magneto-optical disk, conventionally, Generally, data is compressed by utilizing the fact that an image is spatiotemporal information.

For example, a difference between frames of digital image data is taken, and the difference is compressed by DCT (discrete cosine transform (discrete cosine transform)) to record the compressed digital image data. This is conventionally done. Furthermore, in a video conference, etc., in consideration of the small amount of motion in the image, it is necessary to thin out the amount of information, such as recording only one-field data instead of recording a full frame. And so on.

The number of fields to be recorded is reduced instead of one field, and the time information is sacrificed and the spatial information is secured, so that the image is beautiful but the motion may be jerky.

However, if the motion is jerky in this way, the goodness of the moving image is impaired. Therefore, the image data per frame is compressed as much as possible to transmit the full frame, but the spatial resolution is sacrificed. A method of enabling full-motion playback as a video is also being considered.

[0006]

As described above, the conventional digital image signal recording method is devised so as to reduce the recording transmission rate by compressing image data in the time direction or the space direction. .

However, when the recording / transmission bit rate is reduced by only data compression, for example, when compressed in the time direction, the motion of the moving image becomes jerky and becomes an unnatural image. . Further, when compressed in the spatial direction, the spatial resolution is deteriorated to that extent, so that the reproduced image is deteriorated.

That is, in the conventional method, since the bit rate is reduced only by the data compression, one or both of the data in the time direction and the data in the space direction is sacrificed, and the reproduced image is satisfactory. It was hard to get anything.

According to the present invention, even if the recording transmission rate is low,
It is an object of the present invention to provide a recording device for digital image signals, which is devised so that a beautiful reproduced image can be obtained as much as possible and the movement can be smooth.

[0010]

In order to solve the above-mentioned problems, a digital image signal recording apparatus according to the present invention as set forth in claim 1 uses still image information of a background image and the background image from an input digital image signal in advance. A means 22 for dividing the image into information of a moving object, a memory means 23BG for storing the still image information of the background image, a background still image from the input digital image signal, and a separation of the separated still image. Means for obtaining change information for the background image of the memory means 23BG, means for recording the still image information of the memory means 23BG, the change information and the information of the moving object on a recording medium, and the still means for stopping the memory means. Means for updating image information on the basis of the change information, and a signal recorded on the recording medium for reproducing the change information by using the updated still image information in the memory means. Means for re-forming, characterized by comprising a means for re-recording the updated still image information of the memory means, the information of the change information and the moving object, which is re-above formed on the recording medium.

According to a second aspect of the present invention, there is provided a digital image signal recording apparatus according to the present invention, in which, from the input digital image signal, background plane information consisting of a still image of a background image constituting the screen and the above background image are displayed. Separating means for separating one to a plurality of moving object plane information consisting of respective still images of moving objects, and memory means for individually storing the separated background plane information and each moving object plane information A change information detection means for detecting change information for the still image stored in the memory means as the plane information based on the input digital image signal and the output of the memory means, and the plurality of plane information of the memory means. Means for recording on the recording medium the still picture information and the change information from the change information detecting means, and the still picture information in the memory means Means for updating based on the change information, means for reproducing the signal recorded on the recording medium, and means for re-forming the change information using the updated still picture information in the memory means, It is characterized by comprising means for re-recording the updated still image information and the re-formed change information on the recording medium.

[0012]

In the structure of the present invention, for example, when one scene consisting of specific image contents is considered, the image of the scene is divided into a background image considered as a fixed still image and a moving object. . In particular, according to the second aspect of the present invention, a one-frame two-dimensional image of a moving image is regarded as an overlap of two-dimensional planes composed of a background and still images of a plurality of moving objects.

The operation of the invention of claim 2 will be described below. First, a still image of a background image (background plane) that has been separated in advance and a still image of each moving object (animal plane)
And are stored in the memory means. Then, the stored still image is recorded on the recording medium over a period of time in a state where the compression rate is low. That is, a high-resolution still image can be recorded.

After the recording of this preparation is completed, the input digital image signal of the moving image is recorded. At this time, the change amount of the background image and the moving image information or the motion change information of the moving object with respect to the still image are recorded. Only. Since the amount of change is only the movement, the amount of information is small and it is possible to record in real time.

On the reproducing side, a moving object is displayed on the background image.
A moving image can be played back by superimposing it according to the change information.

In this case, each of the background plane and the moving object plane is one still image, and the information of this still image is prepared and recorded in advance. Even if the recording transfer rate is low, a large amount of information is obtained. The data amount can be recorded and transmitted. Therefore, the image quality is high. Since the change information may have a small number of bits, it can be recorded in real time with a margin.

By the way, considering a background image, for example, a background having a wider image frame range than one screen is recorded on the recording medium after recording is completed due to a change in the background image. Then, the amount of change in the background is recorded in real time. This change information can be added to the background plane by the updating means each time and recorded in the memory.

In the present invention, after the recording is completed, the recording signal is re-recorded by using the still plane of the large image frame as the background image. At this time, as the still image information of the background image,
The still image information of the large image frame is recorded in advance. And
As the change information of the background image, for example, only the image frame position information for one screen on the recorded background image is recorded. The image frame position information has a much smaller amount of information than the image information corresponding to the change in the still image. Therefore, by re-recording, it is possible to reduce the amount of recorded information without degrading the image quality.

The above can be performed not only on the background image but also on the moving object. In this case, if a still image corresponding to a change such as rotation of a moving object is prepared as a moving object plane, the data reduction effect is still large.

Data can be further reduced by repeating the re-recording many times. Most of the quality of the reproduced image in the case of the present invention is related to the still image recorded as a plane. Therefore, even if recording is repeatedly performed, the still image recorded as a plane is not deteriorated, so that the image quality is hardly deteriorated. .

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a digital image signal recording apparatus according to the present invention will be described below with reference to the drawings when applied to a disk apparatus using a magneto-optical disk as a recording medium.

The apparatus of this example is equipped with a video camera section using, for example, a CCD solid-state image pickup device, and an image signal obtained by shooting with this video camera is converted into a digital image signal by an A / D converter to generate an optical signal. It is recorded on a magnetic disk. The apparatus of this example is provided with a reproducing apparatus section, which will be described later, together with the recording apparatus.

[Description of Disc Recording Device for Digital Image Signal] FIG. 1 shows a disc drive system and a block diagram of the device of this example. The device of this example comprises a video camera section 1 and
A recording signal system 2, a system controller 3 for controlling the entire system, and a disk drive system 10 are provided, and the image pickup output signal of the video camera unit 1 is recorded via the recording signal system 2. There is.

In the disk drive system 10, 11 is a magneto-optical disk. The magneto-optical disk 11 is housed in a cartridge 11A. In addition, a pregroove for controlling a light spot (for tracking control) is formed in advance on the disk 11, and in the case of this example, the pregroove is superposed on a wobbling signal for tracking to obtain an absolute address. Data is recorded. This absolute address data is used for recording track position control at the time of this recording, and for reproduction scanning track position control at the time of reproduction described later.

The disk 11 is rotated by a spindle motor 12. The rotation of the spindle motor 12 is controlled by the servo control circuit 15, and the disk 11 is controlled so as to rotate at a constant linear velocity, for example.

The disk 11 is provided with a shutter. When the disk 11 is placed on the disk mounting tray and loaded in the apparatus, the shutter is opened. A magnetic head 13 for recording is arranged facing the upper part of the shutter opening of the disk 11, and an optical pickup 14 is arranged facing the lower part of the shutter opening of the disk 11.

The optical pickup 14 has a light emitting portion and a light receiving portion, and movement of the optical pickup 14 in the radial direction of the disk 11 is controlled by a feed motor 16. Further, the servo control circuit 15 controls focus and tracking of the optical pickup 14.

The system controller 3 is constructed by mounting a microcomputer and manages the entire operation. This system controller 3 has a key group 4
Gives a key input signal. The key group 4 includes an imaging / recording standby key, an imaging / recording start key, a playback key,
A stop key etc. are included.

In the case of this example, the moving image photographed by the video camera unit 1 is recorded separately into a fixed background portion and a moving portion moving on the background. The fixed background portion is registered in the background plane memory 23BG described later and recorded as a still image.

The moving parts are separated into moving objects, and moving object plane memories 23A1 to 23A to be described later are provided.
Registered in each of the n, the still image of the moving object is recorded, and the change information about the moving object of each moving object plane is recorded.

When the picked-up image is a two-dimensional image 30 as shown in FIG. 2, for example, a fixed still image composed of a stationary structure is extracted as the background plane 31 as shown in the figure. In the example of FIG. 2, an airplane, a monkey, and a car are recognized as moving objects, and they are separated as moving object planes 32, 33, and 34, respectively.

Then, in this example, as shown in FIG. 3, recording of one scene is divided into a preparation period and an actual imaging and recording period. Then, during the preparation period, the above-mentioned still image recording process of the background plane and the moving object plane is performed. In the actual image capturing / recording period, only the change information of the background plane and the change information of the moving object as each moving body plane are recorded.

[Recording of Preparation Period] In this case, the information for one screen is, for example, 480 lines × 72 as shown in FIG.
It is composed of 0 pixels, and the data of 1 pixel is used as the luminance signal Y.
(8 bits) and color information U, V (8 bits). In the case of this example, the moving object plane memories 23A1-2
3An can be constituted by a memory having a capacity capable of writing still picture information for one screen, but the background plane memory 23BG has, as shown in FIG. In, a large-capacity memory that can store pixel information for a plurality of screens is used. That is, the background plane memory 23BG has a capacity capable of writing pixel sample data of (480 × a) lines in the vertical direction and (720 × b) pixels in the horizontal direction. a and b are
It is a numerical value of 1 or more.

Then, in this preparation period, in FIG. 5, the information of the separated background image BGs for one screen (hereinafter referred to as the initial background plane) is written in the central address position of the memory 23BG. Be done.

Therefore, for example, when the background image BGs at the center position in FIG. 5 is the center, when the camera photographing image frame position such as panning and tilting of the camera is changed around the center background image, the image is within the image frame. The incoming background can be written to this background plane memory 23BG. That is, the background image written in the entire area of the background plane memory 23BG has a wide range of a times in the vertical direction and b times in the horizontal direction with respect to the image frame displayed as one screen. Becomes

Therefore, this background plane memory 23B
Even when the camera is zoomed to the wide angle side at the background image of the image frame for one screen at the center position when the background image is written in the entire range of G, the values of a and b above Within the wide-angle range corresponding to, all the background images in the zoom range are written in the background plane memory 23BG.

In the background plane memory 23BG, the background image of the image frame for one screen obtained during the preparation period, that is, the initial background plane, is panned, tilted, and zoomed during real-time actual image-capturing recording. The amount of change (increase) in the background when the above is performed is gradually added and written.

The moving object plane may of course have the same structure as the background plane.

Next, the recording operation during the preparation period will be described with reference to FIG. The image pickup signal from the camera unit 1 is A /
The signal is supplied to the D converter 21, and for example, one pixel sample is converted into an 8-bit digital image signal and supplied to the signal processing circuit 22. In the signal processing circuit 22, the image of the scene captured by the camera unit 1 is used as a background plane (initial background plane) composed of a static background of a stationary image and a still image of each moving object moving on the background. It is separated into a moving body plane consisting of drawings.

Then, in the signal processing circuit 22, the separated initial background plane is written in the central address shown in FIG. 5 of the background plane memory 23BG. In addition, n separated moving object planes are written in the moving object plane memories 23A1 to An (n is a natural number), respectively. A specific example for separating the background plane and the moving object plane will be described later.

As described above, the plane memory 23 is separated into the background plane and the plurality of moving object planes.
The image information of each still image written in the BG and 23A1 to 23An is as shown in FIG.
As shown in the time chart of (4), it is recorded in the disk 11 in advance in the preparation period before the image pickup and recording are actually started by the video camera.

In this case, the plane information for one screen is composed of 480 lines × 720 pixels as shown in FIG. 4, and the data of one pixel is the luminance signal Y and the color information U, V. Since it is composed of 16 bits, each still image information for one screen has an information amount of about 5.6 Mbits. The data can be recorded on the disc 11 without being compressed as it is, but if the recording rate of the data on the disc is 1.2 Mbps, it takes about 5 seconds to record one still image. It takes 20 seconds with 4 planes.

Therefore, in this example, the image information written in the plane memories 23BG and 23A1 to 23An is supplied to the compression circuit 24, and the plane information is appropriately compressed and supplied to the recording processing circuit 25. To be done. In the recording processing circuit 25, data processing conforming to the recording format of the disk 11 is performed, for example, the data has a sector structure. The output data of the recording processing circuit 25 is sequentially supplied to the recording magnetic head 13 via the head drive circuit 27 and is magneto-optically recorded on the disk 11.

In the compression circuit 24, the data compression rate is 1/1
If it is 0, for example, the plane information of four sheets can be recorded with the preparation time of 2 seconds. In the case of transmitting a full frame of moving image data having the same information amount at 1.2 Mbps, the data compression rate is 1/100 or more. Therefore, compared with this, the deterioration of the image quality of the plane information is very small.

[Actual Image Recording and Recording Period] In this example, even in the image capturing and recording period after the actual image capturing and recording start key is operated in the video camera unit 1, first, in the same manner as the above-described preparation period, the signal The processing circuit 22 separates the background still image and each moving object still image from the image pickup signal. Then, the separated still image is compared with the initial background plane and moving object plane information registered in the background plane memory 23BG and the moving object plane memories 23A1 to 23An to generate change information.

As for the background still image, as shown in FIG. 5, the direction of change and the amount of change (pan, pan, and so on) are based on the position of the image frame of the still image BGs of the initial background plane on the background plane memory 23BG. Information Vs of tilt direction and amount, further zoom ratio, etc.) and image information ΔPs of the background still image change are generated as change information for the background plane. Further, for each moving object, the image information ΔPm of the difference between the moving direction and the moving amount Vm of the moving object and the moving object plane due to the movement change such as rotation or shape change is generated.

Then, the change information generated as described above is recorded on the disk 11 in real time. That is, the change information generated as described above is supplied to the compression encoding circuit 26, compression encoding is performed at an appropriate compression rate, and the head drive circuit 27 is performed via the recording processing circuit 25.
Supply to. As a result, on the disk 11, as shown in the time chart of FIG. 6A, the change information ΔPs and Vs regarding the background image, and the change information Δ regarding each moving object.
Pm1 to ΔPmn and Vm1 to Vmn are recorded.

In this case, as will be described later, the change information to be recorded has a smaller number of bits as compared with the case where image information is data-compressed and transmitted, and even at a low recording transmission rate of 1.2 Mbps, You can record more than enough in real time. A specific example of the above-described change information detection method will be described later.

Along with this recording, the signal processing circuit 22 causes the image information corresponding to the change in the background still image, that is, the pan,
A process of writing the image information of the area increased as the background due to the tilt or the like into the background plane memory 23BG is also performed. For example, when the image frame position changes due to panning, tilting, etc., and the background still image of the captured portion becomes the still image BGp shown by the one-dot chain line in FIG. 5, the image information shown by hatching in FIG. 5 is stored in the memory 23BG. Added to. In this way, the information about the background plane stored in the background plane memory 23BG becomes the information about the background image having a wider range than one screen. However, in this imaging / recording mode, the initial background plane is the basis for generating the change information about the background.

Data is recorded on the magneto-optical disk 11 as follows. That is, the head drive circuit 2
By being supplied to the recording magnetic head 13 via 7, the magnetic field modulated by the recording data is applied at a predetermined position of the disk 11. Further, the laser beam from the optical pickup 14 is applied to the same position on the disk 11. At the time of this recording, the recording track is irradiated with laser light having a constant power larger than that at the time of reproduction. Data is recorded on the disk 11 by thermomagnetic recording by this light irradiation and the modulation magnetic field by the magnetic head 13.
The magnetic head 13 and the optical pickup 14 are both configured to be able to move in the radial direction of the disk 11 in synchronization with each other.

At the time of recording, the output of the optical pickup 14 is supplied to the address decoder 29 via the RF amplifier 28, and the absolute address wobble-recorded in the pre-groove provided along the track of the disk 11 is recorded. The data is extracted and decoded. Then, the detected absolute address data is transferred to the recording processing circuit 25.
Is supplied to the disc 11 and inserted into the recording data,
Recorded in. Further, the absolute address data is supplied to the system controller 3 and used for recognition of the recording position and position control.

The TOC (Table Of Information) provided on the innermost circumference of the disc contains information on which track, and in which sector the background plane information, moving object plane information and change information of each scene are recorded. C
It is recorded in a disc management area called an ontents area.

During this recording, the signal from the RF amplifier 28 is supplied to the servo control circuit 15, and the control signal for the constant linear velocity servo of the spindle motor 12 is formed from the signal from the pre-groove of the disk 11. The spindle motor 12 is speed-controlled.

[Embodiment of Plane Separation Processing Circuit] FIG. 7
FIG. 4 is a block diagram of an embodiment of a plane separation processing circuit for separating a background plane and a plurality of moving object planes in the signal processing circuit 22.

That is, 1-pixel 8-bit image data from the A / D converter 21 through the input terminal 41 is supplied to the frame memory 42 and the subtraction circuit 44.
And the subtraction circuit 45. Further, the input image data is supplied to the moving object plane separation circuit 62 via the AND gate 61.

The frame memory 42 stores 1-pixel 8-bit data for one frame, and the subtraction circuit 44
Pixel data corresponding to the same sampling position in the previous frame is subtracted from the input pixel data. This subtraction circuit 4
The difference output of 4 is supplied to the absolute value conversion circuit 46, converted into an absolute value, and supplied to the comparison circuit 47.

The threshold value θ1 is supplied to the comparison circuit 47 through the terminal 48. When the absolute value of the difference output from the absolute value conversion circuit 46 is less than the threshold value θ1, it becomes “1”, and the threshold value θ1. In the above case, a determination output that is "0" is obtained. This determination output is supplied to the weight coefficient control circuit 49.

In FIG. 7, 23 BGs is a background plane memory having a capacity capable of storing a background image (720 pixels × 480 lines) for one screen. Memory 23BG
A background plane image (still image) is stored in s.

Reference numeral 50 is a weight coefficient memory in which the weight coefficient of one frame is stored. This weight coefficient memory 5
In 0, for example, a 3-bit weighting coefficient is stored.

Frame memory 42, background memory 23BG
The s and weight coefficient memory 50 are commonly address-controlled by the output of the address control circuit 43 so that the same address is designated.

In the subtraction circuit 45, the image data from the background plane memory 23BGs is subtracted from the input pixel data, the difference output of this subtraction circuit 45 is supplied to the absolute value conversion circuit 51, and the absolute value of the difference output is obtained. The absolute value of the difference from the absolute value conversion circuit 51 is supplied to the comparison circuit 52,
The absolute value of the difference output between the input pixel data and the background pixel data is compared with the threshold value θ2 through the terminal 53, and
From the comparison circuit 52, a determination output that becomes “1” when the value is less than 2 and becomes “0” when the threshold value θ2 or more is obtained. The determination output from the comparison circuit 52 is supplied to the weight coefficient control circuit 49.

The difference output between the input pixel data from the subtraction circuit 45 and the background pixel data is also supplied to the multiplication circuit 54, and is multiplied by the weighting coefficient α generated from the weighting coefficient control circuit 49. The multiplication output of the multiplication circuit 54 is the addition circuit 5
5 and is added to the background pixel data from the background plane memory 23BGs, and the addition output is written to the background plane memory 23BGs.

The weighting factor from the weighting factor control circuit 49 is
The weight coefficient read out from the weight coefficient memory 50 while being written in the weight coefficient memory 50 is supplied to the weight coefficient control circuit 49.

The weight coefficient control circuit 49 determines whether the pixel data is a moving pixel from the determination outputs of the comparators 47 and 52.

In the above configuration, the background plane memory 23BGs, the subtraction circuit 45, the multiplication circuit 54, and the addition circuit 55 form a digital filter using the background plane memory 23BGs as a one-frame delay element.
That is, when the weighting factor is α, the input pixel data of the kth frame is Zk, and the background image data read from the background plane memory 23BGs is X (k−1), k
The background pixel data (estimated value) Xk of the frame is represented by the following equation.

Xk = α · (Zk−X (k−1)) + X (k−1) = (1−α) · X (k−1) + α · Zk In this example, one scene in which the background does not change In between, α is fixed at 1/16, for example. The white noise included in the input image is removed by repeating the operation represented by the above equation over a plurality of frames, and the S / N of the background image stored in the background plane memory 23BGs is improved.

Also, when the background changes, such as when the scene changes, that is, when the image-capturing scene changes to another image-capturing scene, the response time is shortened and the influence of colored noise is avoided. And the weighting factor α is 1
Multiply by 2 from / 16 every frame. That is, the background image is gradually updated by using the weighting coefficient α that increases exponentially as 1/16 → 1/8 → 1/4 → 1/2 → 1. Therefore, the weighting factor α is 5
There are types, and each is represented by 3 bits.
The weighting coefficient α is set to a power of 2 because the multiplication circuit 54
This is because the shift register or the selector is realized.

In this example, after the initial state has passed, the background still image data is stored in the background plane memory 23BGs. The subtraction circuit 45 and the absolute value conversion circuit 51 detect the absolute value of the difference between the current pixel and the background pixel. The absolute value of this difference is compared with the threshold value θ2 by the comparison circuit 52, and when the absolute value of the difference is less than the threshold value θ2, it is determined that the current pixel belongs to the background image, and Processing is performed.

That is, at this time, the weighting coefficient α is 2 ⁻⁴
It is fixed at (= 1/16). Then, in the multiplication circuit 54, the output of the subtraction circuit 45 is multiplied by this weighting coefficient α, and the output of the background plane memory 23BGs and the addition circuit 5 are added.
It is added at 5. Then, the added output is written to the same address in the background plane memory 23BGs,
The background plane memory is updated. The weight coefficient at this time is written in the weight coefficient memory 50.

When the comparison circuit 52 determines that the absolute value of the difference between the current pixel and the background pixel is greater than or equal to the threshold value θ2, the current pixel detected by the subtraction circuit 44 and the absolute value conversion circuit 46 Whether the absolute value of the difference from the corresponding pixel in the frame is less than the threshold value θ1 or more than the threshold value θ1 is examined as the output of the comparison circuit 47. When the output of the comparison circuit 47 is less than the threshold value θ1, the following processing is performed.

That is, when the value is less than the threshold value θ1, the background coefficient is changed due to a scene change or the like, and the weighting coefficient α (= 1/16) initially stored in the weighting coefficient memory 50. Is read out, and the weighting coefficient α is multiplied by the output signal of the subtraction circuit 45 by the multiplier 54. Therefore, the background pixel update made in this frame is similar to the one described above, where Xk = 15/16 · X (k−1) + 1/16 · Zk.

When the background pixel is updated, the weighting factor control circuit 49 doubles α, and it is determined whether or not the doubled new weighting factor is larger than 1. If it is smaller, this doubled weight coefficient α is stored in the weight coefficient memory 50. Starting with a weighting factor of 1/16, (1/8 → 1/4 → 1/2 →
1) and the weighting factor α changes for each frame.

The background is switched, the weighting factor α changes as described above, and the same background pixel updating process as described above does not proceed until 5 frames after α = 1. Therefore, even if the colored noise is erroneously detected as a new background pixel and undergoes the process of changing the weighting coefficient, the correct background pixel is stored. The way of changing the weighting coefficient α is set so that the responsiveness at the time of updating the background pixel is improved and the colored noise can be removed.

When the comparison circuit 47 determines that the absolute value of the difference between the current pixel and the previous frame pixel is greater than or equal to the threshold value θ1, it is determined that the current pixel is a moving pixel. In this case, the background plane memory 2
The 3BGs are not updated. The motion pixels are subjected to motion plane separation processing as described below.

In the weighting factor control circuit 49, the comparison circuit 52 detects that the absolute value of the current pixel and the background pixel is greater than or equal to the threshold value θ2, and the output of the comparison circuit 47 determines that the current pixel is the current pixel. The absolute value of the difference from the previous frame pixel is
When it is equal to or more than the threshold value θ1, it is detected as a moving pixel.

The motion pixel detection signal from the weighting coefficient control circuit 49 is supplied to the AND gate 61, and the input digital pixel data from the input terminal 41 input to this AND gate is gate-controlled. This AND gate 61
Goes high and opens when the current pixel is a motion pixel. Therefore, when the input pixel (current pixel) is not a moving pixel, the output of the AND gate 61 becomes "0",
When the input pixel is a motion pixel, the pixel data (this is data other than “0”; hereinafter, this is referred to as non-zero data) is output from the AND gate 61.

Reference numeral 62 denotes a moving object plane separation circuit, which includes a difference memory (frame memory) 62M capable of storing pixel data for one frame, and the output of the AND gate 61 is input to this memory 62M. This memory 62M receives the address control signal from the address control circuit 43, and the above-mentioned frame memory 42 and background plane memory 23BG.
It receives the same address control as the s and weight coefficient memory 50.

Therefore, the background image is removed from the current image in the difference memory 62M, and a difference image consisting of only the images of a plurality of moving objects consisting of a set of moving pixels consisting of non-zero data is stored. . And FIG.
As shown in, as data of pixels other than the non-zero pixel data of the moving object, “0” data is written in the memory 62M.

In this way, one 2
The pixel data of a plurality of moving objects in the three-dimensional image are
Written as non-zero pixel data having a level other than "0", the pixel data of the still image portion of the background image other than the pixels of the moving object is stored as all "0" data. Therefore, if a plurality of moving objects do not overlap each other, the pixel data in the difference memory 62M are sequentially scanned, and non-zero pixel data that is not "0" are associated and merged (integrated) by neighboring pixels. , It becomes possible to separate the moving object plane which consists of only each of the moving objects.

Reference numeral 63 denotes a microcomputer, which scans the difference memory 62M of the moving body plane separation circuit 62, separates planes for each moving object as follows, and outputs information on the separated moving object planes to corresponding addresses. In, the data is written in each of the moving object plane memories 23A1 to 23An. In addition, the moving body plane memory 23
All “0” s are written in advance in all the addresses of A1 to 23An, and only the pixels of each moving object have the same address as the difference memory 62M.
It is written in any of the moving object plane memories.

10 and 11 are flowcharts of the processing for separating the moving object plane of the microcomputer 63. That is, in the process of separating the moving object in this case, first, in step 101, non-zero pixel data is searched (since the moving pixel is not 0, the moving pixel is searched). Then, if non-zero pixel data is found in step 102, the process proceeds to step 103 to check whether the pixel data around it is non-zero. In the case of this example, as shown in FIG. 9, the data of 8 pixels a to h on the upper, lower, left, and right sides of the pixel of interest x is checked.

Then, in the next step 104, 8
If none of the data of the pixels a to h is non-zero, the pixel of interest x is regarded as an isolated point and the step 104 is performed.
Then, the procedure returns to step 101 to search for the next motion pixel.

In step 104, if any one of the eight pixels a to h is a non-zero pixel, the process proceeds from step 104 to step 105, and the pixel d to the left of the target pixel x and above (one line before). It is checked whether or not the pixel and b are non-zero pixels, and the process proceeds to the next step 106.

In the next step 106, it is determined whether the left and upper pixels d and b are both non-zero,
If both are not non-zero, that is, they are not motion pixels,
In step 107, a new number is set as the memory number of the moving object plane memory (hereinafter, simply referred to as the memory number). Then, in step 108, the memory number is stored in correspondence with the address of the pixel.
After that, the routine proceeds to step 109, where it is judged whether or not the scanning of all the pixels of the difference memory 62M is finished. When all the scanning is finished, this processing routine is finished. If all the scans have not been completed, the process returns to step 101 and the search for the next motion pixel is started.

If it is determined in step 106 that at least one of the left and upper pixels d and b is a non-zero pixel, the process proceeds from step 106 to step 110, and both are non-zero. To be determined. When it is determined that both are non-zero, the process proceeds from step 110 to step 111, and the memory numbers stored in the microcomputer 63 for both pixels d and b are checked. And next step 1
In step 12, it is determined whether or not the memory numbers of both pixels d and b match.

As a result of the determination in step 112, when the memory numbers of both pixels d and b match, the process proceeds from step 112 to step 108, and the memory number is stored in correspondence with the address of the target pixel x. .

If it is determined in step 112 that the memory numbers of both pixels d and b do not match, the process proceeds from step 112 to step 113 to select the memory number of the left pixel d. And stores the memory number in association with the target pixel x,
The memory number of the left pixel d and the memory number of the upper pixel b are related, and information (called merge information) indicating that the pixel is a pixel of one moving object even if the memory numbers are different is stored.

This is because the moving object is a pixel at a skipped position in the data of a certain horizontal scanning line, but as a result of searching the pixels of the subsequent line, it is found that the moving object is connected as a pixel of the same moving object. The case is shown.

As a result of the discrimination in step 110, when neither is non-zero, this step 110
From step S115 to step 115, it is determined whether or not the left pixel d is non-zero. As a result of the determination, when the left pixel d is non-zero, the procedure proceeds to step 116, the memory number of the pixel d is checked, and then step 10
In step 8, the memory number corresponding to the address of the target pixel x is stored.

As a result of the determination in step 115, the left pixel d
Is not non-zero, that is, when it is determined that the upper pixel b is non-zero, the process proceeds to step 117, the memory number of the upper pixel b is checked, and then step 1
08, corresponding to the address of the target pixel x,
The memory number is stored.

As described above, after step 108, the routine proceeds to step 109, where it is judged whether or not the search for all the pixels in the difference memory 62M is completed,
If not, the process returns to step 101 and the above processing routine is repeated, and when the search for all pixels is completed,
This processing routine ends.

As a result of the pixel search of the difference memory 62M, the internal memory of the microcomputer 63 stores the same memory number and associated memory for each moving object with respect to the address of the pixel included in each moving object. The number is stored with the information associating both memory numbers.
The microcomputer 63 sets the memory numbers of the pixels recognized as the same moving object to the memory number No. of one moving image plane memory.
Correspond to. As a result, each moving object can be separated as separate moving image planes as follows.

That is, the microcomputer 63 uses the difference memory 6
The moving pixel data is sequentially read from 2M. The read output of the difference memory 62M is the moving picture plane memory 23.
It is input to each of A1 to 23An. Further, the microcomputer 63 sets the read pixel as described above and supplies the write pixel address (which may be the same as the read pixel address) only to the moving picture plane memory of the stored memory number No, and the moving pixel Is written in the moving picture plane memory having the memory number No.

Thus, the moving object plane memory 23A
Each of 1 to 23An has one moving object,
It is separated and stored separately.

In the above method of separating the moving object plane, the difference memory 62M is searched for pixels horizontally and vertically as in the television scanning, and the pixels included in the same moving object are merged. When one motion pixel is detected, the surrounding pixels are sequentially searched to track non-zero pixels and merged, and the merged pixel data is sequentially written to one motion object plane memory at the same time. In this way, the moving object plane memory for one moving object may be completed.

Even if two moving objects overlap each other at a certain point of time, the moving objects can be observed separately after a lapse of a predetermined time. By rewriting, the moving object plane information including only the moving objects can be stored in each moving object plane memory by the above method.

[Generation of Change Information of Background Image and Change Information of Moving Object] Next, a configuration example of a change information generation circuit for the initial background plane and a change information of each moving object in the signal processing circuit 22 will be described. This will be described with reference to FIG.

These pieces of change information are obtained from the current image information obtained by shooting with the video camera unit 1, the background plane memory 23BG and the moving object plane memories 23A1 to 23A.
It is generated using n data. The circuit of FIG. 12 operates from the time when the imaging / recording start key is operated after the above-described preparation period has elapsed.

That is, the image pickup data from the A / D converter 21 is separated into the background plane information for one screen and the plane information for each moving object by the plane separation circuit of the signal processing circuit 22 described above. Information about one frame of the background image and each moving object is stored in the frame memory 7
1BG and 71A1 to 71An. The frame memories 71BG and 71A1 to 71An have a two-frame buffer configuration. When the background image and the information of the moving object are being written to one frame memory, the background plane from the other frame memory and The information data of the moving object plane is read out and the data is used for generating the change information.

That is, the background image information from the frame memory 71BG is supplied to the image frame position change detection circuit 72BG, and the image information of each moving object from the frame memories 71A1 to 71An is supplied to the motion change detection circuit 72A1.
~ 72An. Then, the still image information of the initial background plane from the background plane memory 23BG is supplied to the image frame position change detection circuit 72BG, and the moving object plane information stored in the moving object plane memories 23A1 to 23An during the preparation period is It is supplied to the motion change detection circuits 72A1 to 72An.

In the image frame position change detection circuit 72BG, the background image information of the initial background plane and the frame memory 71BG
Background image information is compared, pattern matching processing between them is performed, and image information ΔPs such as the hatched portion shown in FIG. 5 excluding the matching portion is obtained. At the time of this comparison processing, the information Vs on the moving direction and the moving amount of the camera is referred to. With this information Vs, the search time for matching can be shortened.

Although this information Vs is not shown, the camera unit 1 is provided with a sensor means such as a gyroscope for detecting the moving direction and distance when the camera is moved by tilting or panning. This sensor means is used for detection. Further, for example, when the present device is attached to a tripod for an image pickup device to perform shooting,
A sensor for detecting the pan and tilt directions of the camera and the amount of movement is provided on the tripod.
Alternatively, s may be obtained.

The change information Vs and ΔPs for the initial background plane thus obtained are supplied to the compression encoding circuit 26.

In the motion change detection circuits 72A1 to 72An, the moving objects stored in the moving object plane memories 23A1 to 23An and the frame memories 71A1 to 71A are stored.
By pattern matching with each moving object image from An, the motion vector, that is, the direction of motion and the amount of motion for that moving object are obtained.

In this case, since the moving object is stored in the memory as a moving object plane in advance, if the shape does not change, pay attention to a specific representative point or a representative block, and the representative point or the representative block. By performing the pattern matching with respect to, the motion vector for the entire moving object can be extracted, and the matching process can be performed in a relatively short time. The same can be said when detecting the image frame position information of the background image.

When the moving object changes its direction or shape, the pattern matching causes a large error.
Therefore, in this example, together with the motion vector, the error amount is transmitted as motion change information.

In this way, the motion change detection circuits 72A1-7A7
The motion vector and the matching error information for the moving object in each moving object plane memory obtained by 2An are supplied to the compression encoding circuit 26.

The compression coding circuit 26 compresses the input data. As described above, the amount of data after compression is much smaller than that of image information, and it is possible to easily record the data on the disc in real time.

When the camera is zoomed,
The zoom ratio information is included in the change information, and the information of the background plane and the moving object plane is passed through a low-pass filter (data thinning) according to the zoom ratio for comparison with the image pickup signal.

The post-movement position of the moving object in each moving object plane memory can be easily detected as an address on the memory by using the detected motion vector. Therefore, it is possible to recognize a state in which the moving objects overlap with each other by making the pixel addresses of the plurality of moving objects the same. As described above, when a plurality of moving objects are overlapped with each other, the depth between the moving objects is detected depending on which pixel of the moving object appears as the pixel of the part in the current image. Then, the depth information is transmitted together with the motion information. Note that the depth information is also obtained for the background image and the moving object.

Further, as the motion change information about the moving object, a predicted motion vector as in the following example and the object deformation information may be transmitted. That is, in the example of FIG. 13, the frame information of each moving object extracted from the input image information from the frame memories 71A1 to 71An is supplied to the difference calculation circuits 73A1 to 73An.

In addition, the moving object plane memories 23A1-2
The 3A moving object plane information is used as the prediction circuits 74A1 to 74A7.
4An, and is supplied to 4An, and the motion vector predictor generating circuit 75A1
Based on the predicted motion vector from ~ 75An, the frame image data of each predicted moving object after the movement is obtained from this. Then, the predicted frame image data of each moving object is converted into the difference calculation circuits 73A1 to 73A1.
73An and is supplied to the frame memories 71A1 to 71A1.
The difference from the frame information of each moving object extracted from the input image information from An is calculated.

The difference calculation circuits 73A1 to 73An output the difference of the image of the moving object to the compression encoding circuit 26 as output data. In addition, the difference calculation circuit 73A
1 to 73An obtain the difference of the motion vector from the difference of the image of the moving object and supply it to the compression encoding circuit 26 as output data and also to the predictive motion vector generating circuits 75A1 to 75An for the next frame. Generate a motion vector predictor for each moving object.

In the above example, the background image and the still image of the moving object are separated from the input image. However, when the background image and the moving object are previously separated from each other, it is possible to take a picture with the camera. In advance, each of them is individually imaged and written in the background plane memory 23BG and the moving object plane memories 23A1 to 23An,
It can be recorded on the disk 11.

In the above embodiment, the preparation period is set before the actual image recording and recording, and the background plane and the moving object plane are separated and recorded on the disc during the preparation period. Since the amount of information is very small, it is possible to execute recording of still image plane information to recording of motion change information in real time without providing a preparation period. For example, assuming that one scene is 10 seconds, in the above example, the recording of four pieces of plane information can be performed in 2 seconds.
By accumulating the motion change information in the buffer memory, real-time image recording can be performed without providing a preparation period.

[Explanation of Re-Recording] After recording one scene as described above, the background plane memory 23BG stores all the background images used in the scene, as described above. ing. On the disk 11, the still image BGs of the initial background plane and the still image B
Although the changed still image information (increase information) for Gs is recorded, if the contents of the background plane memory 23BG after recording is recorded as the background plane information instead of the initial background plane, the image frame in the background plane information is recorded. By recording the information indicating the position as the background information of each frame, it is possible to easily form the background still image of each frame on the reproducing side. Moreover, there is no deterioration of the reproduced image.

In view of the above points, the present invention reproduces the information recorded on the disk 11 and re-records it.

That is, as shown in FIG. 6B, first, as the background plane information, the information of the background plane memory 23BG after the recording, that is, the still image information BGL of the enlarged image frame is recorded. Next, in this example, the still image information of the reproduced n moving object planes is recorded as it is.

Next, the change information is recorded. At the time of this recording, the change image information ΔP for the initial background plane is recorded.
The recording of s is not performed, the change position with respect to the image frame position of the initial background plane is detected and generated, and only this information is recorded.

That is, first, the information ST of the image frame position of the initial background plane on the recorded enlarged background plane BGL is recorded. This is the background plane memory 23BG
For example, the address information of the upper left corner of the still image of the enlarged background plane may be used. Next, the changed image frame position information FLs obtained from the information Vs of the image frame position change direction and amount of change of the background image of each reproduced frame is recorded as the background image information of the frame. The image frame position information FLs may also be address information of the upper left corner of the image frame in the still image on the enlarged background plane in the background plane memory 23BG.

However, when the reproduction side is configured to obtain the image frame position information of the background image of the frame from the information Vs, the information Vs of the change direction and the change amount may be re-recorded as it is. Good.

By re-recording as described above,
With respect to the background image, it is not necessary to record the information Ps corresponding to the image change of each frame (or field), and the amount of recorded information can be reduced. Moreover, even in the case of re-recording, there is no deterioration of the image quality of the image, unlike the case of the recording of the copy in the VTR, for example.

In the above example, only for the background plane,
Although the initial plane information was updated and the recorded data was reduced by re-recording, the plane information is similarly updated and re-recorded for the moving object plane to further reduce the recorded data amount. You can

As for the moving object, it is possible to reduce the motion information by recording, as the still image plane information, a plurality of pieces of still image information having different image contents, instead of the information of the enlarged image frame.

That is, for example, assuming a moving image of a car, still images of the front view, side view, and rear view of the car are prepared as car planes, and plane numbers are given to the respective planes.
Then, in obtaining the change information about the car in the captured and input current image, by recording the plane number with a small difference (change amount) from the car plane and the change amount, the record data as the change information is recorded. The amount can be reduced.

[Description of Disc Reproducing Device for Digital Image Signal] FIG. 14 is a block diagram of an embodiment of the disc reproducing device of this example. In this example, the same parts as those of the disc recording apparatus of the example of FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

When the disk 11 is loaded into the apparatus, the apparatus first takes in the TOC area of the disk, and the system controller 3 records the recording positions of the background plane and the moving object plane of each scene and the movement change information thereof. Recognize position.

Then, the system controller 3 first reproduces the information of the background plane and the plurality of moving object planes of the scene to be reproduced from the TOC area information.

These pieces of image information taken out from the disk 11 are supplied from the RF circuit 28 to the reproduction processing circuit 81, where data of a predetermined recording format such as a sector structure is decoded and the decoded data is expanded. And the plane separation circuit 82. And
In this circuit 82, each plane information compressed at a low compression rate is decompressed and separated for each plane information. The background plane information is stored in the background plane memory 83BG, and the animal body plane information is stored in the animal plane information. It is written in the body plane memories 83A1 to 83An, respectively. This completes the preparation for starting moving image reproduction.

Next, the image frame position information, motion change information, depth information, etc. of the background image of the scene are TOC from the disc.
RF is extracted in real time by referring to area information
The data is supplied to the data decompression / decoding circuit 84 via the circuit 28 and the reproduction processing circuit 81. Then, the motion change information and the like are decompressed and decoded, and supplied to the signal processing circuit 85.

Further, the signal processing circuit 85 includes a background plane memory 83BG and a moving object plane memory 83A1.
Each still image information from 83An is also supplied. In the signal processing circuit 85, the background plane memory 8
A background image at the image frame position based on the image frame position information is read from the 3BG, and the moving object plane memory 8 is added to this background image.
The images of the moving objects from 3A1 to 83An are combined using the motion change information and the depth information of the moving objects from the decompression decoding circuit 84.

In other words, a composition is performed in which a moving object is pasted on a frame or field basis at a position according to the motion change information and an overlap according to the depth information (there is also an overlap with the background image) on the background image. The original moving image is obtained.

At this time, the image frame position for the background image is
By operating the image frame position changing key of the key group 4, it is possible to change the recorded image frame position information in the vertical and horizontal directions. That is, when the image frame position change key is operated, the image frame position is changed in the direction specified by the change key with respect to the image frame position determined by the reproduced image frame position information, and the changed image is displayed. The background image at the frame position is read from the background plane 83BG. That is, the image frame position change key can change the image frame position of the background image during reproduction to any position within the range of the background plane.

A reproduction zoom key is provided, and when the reproduction zoom key is operated, the background image of the image frame enlarged or reduced according to the zoom ratio is read from the memory 83BG.
At this time, the data is interpolated or thinned according to the zoom ratio so as to fit the data of one screen of 720 pixels × 480 lines. In this way, regardless of the image frame position at the time of image capturing, the user can also enjoy making a desired picture on the reproducing side.

The moving image data from the signal processing circuit 85 is returned to the original analog signal by the D / A converter 86, is derived from the output terminal 87, and the reproduced image is reproduced on the image monitor device connected to this output terminal. Is projected.

As described above, the information of the background plane and the moving object plane for each scene is first read from the disc, and then the change information is sequentially read from the disc, whereby the moving image of each scene can be reproduced. it can. In this case, since the amount of change information of each scene is very small, the change information of one scene is not extracted from the disk in time with the real time of the moving image, but a buffer memory is provided and the change information of each scene follows each plane information. It is also possible to take out the motion change information, store it in the buffer memory, and perform a process of sequentially reading out the motion change information from the buffer memory in accordance with the moving image.

In such a case, since the moving image reproduction processing and the extraction of the reproduction signal from the disc can be separated, the plane information of the next scene can be recorded on the disc during the reproduction of the previous scene. Can be extracted from and stored in another plane memory. By doing so, it is possible to continuously reproduce a plurality of scenes without interruption.

As described above, according to the present invention, the input image is divided into the background image and the moving object plane, which is recorded with high image quality, and at the same time, the change of the background image and the change of movement of the moving object plane are performed together. Since recording and synthesizing are performed at the time of reproduction, it is possible to record a moving image with high image quality and smooth motion even in the case of a recording medium having a low recording transmission rate.

For example, a compression method of image data called so-called MPEG is conventionally known, but this method sends image information of one frame (still image) at the very beginning, and then the first. This is a method of taking the difference from the image frame of and recording the residual by compressing the data. The number of bits of the image data of the first one frame in this MPEG is, for example, 400 K bits when the data is compressed. This 400 K-bit image has a relatively high image quality.

Since this 400 K-bit image is one frame of information, if this is expressed in bps, one second is:
Since it consists of 30 frames, it corresponds to 12 Mbps.
Therefore, a fairly high quality image is obtained. MP
In the EG, since only the residual information is recorded as the subsequent information, the reproduced image is deteriorated,
The image of the first one frame itself has a good image quality.

On the other hand, according to the above-described configuration of the present invention, the information of the plurality of image planes of the background plane and the moving object plane is recorded as the image data of 12 Mbps equivalent to MPEG, and the bit number is small. The moving image plane is moved based on the motion change information recorded by the number and is combined with the background plane to reproduce the moving image, so the image quality is good and the motion vector Since the information is real-time information, the movement is not jerky and is good.

It should be noted that the motion information separated from the background plane is not recorded separately in the moving object plane composed of still images of a plurality of moving objects as in the above example, but is recorded in a plurality of moving objects. The present invention can also be applied to an apparatus for compressing motion information including the data and recording the data separately from the background plane.

In the above example, the magneto-optical disk is used as the image data transmission medium, but it goes without saying that a tape or other recording medium can be used in the present invention.

[0144]

As described above, according to the present invention, an image is divided into background still image information (background plane) and motion information, and still image information of the background image is recorded on a recording medium. , The background change in one scene of the movie is
In a recording device that records as a difference from the recorded background still image, by reproducing the recorded information and re-recording the still image information of the background image and its change,
The amount of recorded information can be reduced.

For example, when the still image information of the background image is rewritten to the background still image of the enlarged image frame obtained after the end of recording, this has all the changes necessary for the background. It is not necessary to record the image information corresponding to the background change of each field or frame, and instead, the information of a small number of bits that indicates which image frame in the still image is the background is recorded. This is enough, and the amount of recorded data is reduced accordingly.

Further, as for the motion information, when the still picture planes of a plurality of moving objects and their changes are recorded, the still picture planes of each moving object are re-recorded. The amount of recorded information can be reduced by re-recording the amount of change as the amount of information to be recorded.

Further, in the present invention, the image is divided into a still image of the background plane and a still image of the moving object of the moving object plane, and the information of the plurality of still image planes is not compressed or high image quality is maintained. In addition to recording at low compression rate at low speed, motion change information is recorded at high speed with a small number of bits, and on the playback side, the plane of the moving object with good image quality is moved based on the motion change information, Since a moving image is reproduced by synthesizing with a plane, it is possible to obtain a reproduced image with good image quality and good motion without jerky motion.

[Brief description of drawings]

FIG. 1 is a block diagram of a disk recording apparatus as an embodiment of a digital image signal recording apparatus according to the present invention.

FIG. 2 is a diagram for explaining an essential part of the present invention.

FIG. 3 is a diagram for explaining a signal recording timing in the example of FIG.

FIG. 4 is a diagram for explaining the example of FIG. 1.

FIG. 5 is a diagram for explaining an example of a background plane memory 23BG used in an embodiment of the present invention.

FIG. 6 is a time chart for explaining a main part of the present invention.

FIG. 7 is a block diagram of an embodiment of a main part of a digital image signal recording apparatus according to the present invention.

8 is a diagram for explaining the operation of the example in FIG. 7. FIG.

9 is a diagram for explaining the operation of the example in FIG. 7. FIG.

10 is a diagram showing a part of a flowchart of the operation of the example of FIG. 7. FIG.

11 is a diagram showing a part of a flowchart of the operation of the example of FIG.

FIG. 12 is a block diagram of an embodiment of a main part of a digital image signal recording apparatus according to the present invention.

FIG. 13 is a block diagram of another embodiment of the main part of the digital image signal recording apparatus according to the present invention.

FIG. 14 is a block diagram of an embodiment of a reproducing apparatus for a digital image signal recorded by the recording apparatus of the present invention.

[Explanation of symbols]

 22 signal processing device 23BG background plane memory 23A1-23An animal body plane memory 24 compression circuit 26 compression encoding circuit 31 background plane 32-34 animal body plane memory 62 animal body plane separation circuit 62M difference memory 72BG image frame position change detection circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 7/137 Z

Claims (4)

[Claims] 1. A means for dividing still image information of a background image and information of a moving object moving on the background image from an input digital image signal in advance, and a memory means for storing the still image information of the background image. A means for separating a still picture of a background picture from an input digital image signal and obtaining change information of the separated still picture with respect to the background picture of the memory means, still picture information of the memory means, the change information and the motion. Means for recording the information of the object on a recording medium, means for updating the still image information of the memory means based on the change information, and means for reproducing the signal recorded on the recording medium to update the memory means. Means for re-forming the change information by using the still image information, and re-recording the updated still image information in the memory means, the re-formed change information and the moving object information in the recording medium. And a digital image signal recording apparatus. 2. The digital image signal recording apparatus according to claim 1, wherein, with respect to the information on the moving object moving on the background image, each of the moving objects moving on the background image based on the input digital image signal in advance. Separating means for separating one to a plurality of moving object plane information consisting of still images, memory means for individually storing each of the separated moving object plane information, the input digital image signal and the memory means Change information detecting means for detecting change information for the still image stored in the memory means as the plane information, still image information of the plurality of plane information in the memory means, and the change information detecting means Change information from the memory means, a means for updating the still image information of the memory means, and a signal recorded on the recording medium. A means for reproducing and re-forming the change information by using the updated still picture information of the memory means, the updated still picture information of the memory means, and the re-formed change information. A device for recording a digital image signal, comprising a means for re-recording on a medium. 3. The still image information of the plane information of the memory means is recorded without compression or at a low compression rate, and the change information is compressed and recorded. The apparatus for recording a digital image signal according to claim 1 or 2. 4. The digital image signal recording apparatus according to claim 1, wherein the digital image signal is obtained by A / D converting an image pickup output of a video camera.