JP2002354292A - Image processor and its image processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor and its image processing method capable of suppressing the generation of a false signal generated on an image read out from an image pickup element of high resolution by thinning. SOLUTION: In the image processor 10, a system control part 12 instructs a driving signal generation circuit 14 on a prescribed thinning ratio by a control signal 102, the circuit 14 respectively supplies a driving signal 106 generated by considering the prescribed thinning ratio and a timing signal 104 to an image pickup element 16 and a contour correction control circuit 20, an image pickup signal 108 read out in a thinned state from the element 16 in response to the driving signal 106 is converted into picture data 110, the control circuit 20 generates correction control signals 112, 114 for optimum contour correction from the timing signal 104 and supplies the signals 112, 114 to a moving picture processing circuit 220 and a recording processing circuit 222 in a signal processing part 22, and respective circuits 220, 222 apply contour correction corresponding to the control signals 112, 114 to picture data 118.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and an image processing method thereof, and is applied to, for example, a digital camera or an image input apparatus. An apparatus and a method suitable for use in image processing.

[0002]

2. Description of the Related Art As the number of pixels in a digital camera increases, the frame rate in moving image shooting in a movie mode has become a problem. Vertical thinning-out reading has been proposed to increase the frame rate in reading from an image sensor. Below 1.5 million pixels, ie 1
The case of 280 × 1024 pixels will be described as an example. The image sensor is C
A CD (Charge Coupled Device) is used. Drive speed
Assuming 12.2725 MHz, 1H = 1560 clocks and 1V = 1050H indicate that 1V requires 133 msec. The number of frames read from this is about 7.5 frames / sec. In this case, the moving image display is not smooth.

As is clear from the above relationship, the vertical 1 /
In case of 2 thinning, 1V = 525H to about 15 frames / sec, vertical 1
In the case of / 4 thinning out, 1V = 262.5H to about 30 frames / sec. As described above, by performing the vertical thinning-out reading,
The frame rate speed is improved, and particularly in the latter case, a moving image display that is smooth and comfortable is provided.

VR used for display while maintaining the vertical resolution
Japanese Patent Application Laid-Open No. 9-247543 discloses a digital electronic image pickup device which does not require an AM (Video Random Access Memory) and enables high-speed reading of an image pickup signal. A solid-state imaging device for selecting a first imaging mode for reading out a first number of pixels and a second imaging mode for reading out a second number of pixels less than the first imaging mode; Signal processing means for generating an image signal by processing an output signal of a solid-state image sensor, display means for displaying the image signal, storage means for storing the image signal as a digital image signal, signal processing means and display means A data switching unit for inputting and outputting a signal between the storage unit and the storage unit, and when generating an image signal to be stored in the storage unit, operates in the first imaging mode and is input to the display unit. When an image signal is generated, the solid-state imaging device and a control unit that controls the data switching unit are configured to operate in the second imaging mode.

[0005]

By the way, it is known that an image subjected to the above-mentioned thinning-out processing is sequentially and strongly affected by aliasing distortion as the thinning-out rate increases. The output image may be degraded in image quality.

[0006] Although different from the image quality deterioration caused by the thinning-out processing, there is a case where a reproduced image is deteriorated by image encoding for saving the memory capacity when storing the image in the replay memory. The television receiver disclosed in JP-A-9-83958 for the purpose of improving image quality deterioration due to image encoding
/ D conversion circuit, a filter circuit provided before or after the circuit, an encoding / decoding circuit for encoding a digital video signal, storing it in a memory, reading it out from the memory and decoding it, and an encoding / decoding circuit Selecting means for selecting a digital video signal to a decoding / decoding circuit or a digital video signal from the encoding / decoding circuit; and contour correcting means for performing contour correction on the digital video signal from the selecting means. By switching the filter circuit in accordance with the selection, an appropriate image quality is maintained in a real-time moving image as in the related art, while noise due to encoding is reduced to improve image quality deterioration.

[0007] In the former example, when the vertical resolution is desired to be maintained, the first imaging mode is merely selected and satisfied with respect to image quality deterioration. Further, the latter television receiver has a filter characteristic of a filter circuit between a case where a real-time moving image is output without passing through an encoding / decoding circuit and a case where a moving image reproduced from the encoding / decoding circuit is output. It is described that image quality deterioration due to encoding is improved by switching the gain or peaking frequency of the contour correction of the contour correction circuit individually or by combining them. However, the application is a television receiver that displays two types of moving images, and is different from the image processing apparatus of the present invention.

The present invention solves such disadvantages of the prior art, and provides an image processing apparatus and an image processing method capable of suppressing the generation of a false signal occurring in an image subjected to thinning-out reading from a high-resolution image sensor. The purpose is to do.

[0009]

In order to solve the above-mentioned problems, an image processing apparatus according to the present invention provides an image processing apparatus for converting an image signal obtained from all pixels representing an image into a thinned image signal at a predetermined thinning rate. In an image processing apparatus that performs signal processing by using an image pickup apparatus, an image pickup unit that outputs an image pickup signal obtained by photoelectrically converting each of all pixels, and a drive signal used to generate and read out the image pickup signal And a drive signal generating means for generating a drive signal in consideration of a predetermined thinning rate, and a control signal for performing signal processing control based on a timing relationship between the drive signals indicating the predetermined thinning rate. A digital image signal read in consideration of a predetermined thinning ratio in response to the drive signal, and supplied to the digital image signal. A signal processing means for performing signal processing for moving image display or recording in response to the control signal of, and a system control means for instructing a predetermined thinning rate to the drive signal generation means, wherein the signal processing means It is characterized by including moving image processing means for performing contour correction processing and performing processing for moving image display, and recording processing means for performing contour correction processing on a digital image pickup signal and performing recording processing.

In the image processing apparatus according to the present invention, the system control means instructs the drive signal generation means to determine a predetermined thinning rate, and the drive signal generation means generates a drive signal in consideration of the predetermined thinning rate. In response to the drive signal, the imaging means reads out an imaging signal in consideration of a predetermined thinning ratio and converts it into a digital imaging signal, and the control means performs signal processing control based on the supplied timing relationship. A control signal to be generated is output to the signal processing means, and the digital image pickup signal supplied by the signal processing means is processed in response to a control signal from the control means, and a signal processing for moving image display or contour correction processing and recording is performed. Signal processing by the moving image processing means and the recording processing means, respectively. In association with the thinning ratio is prevented degradation in image quality appropriately subjected to Guo correction process.

According to another aspect of the present invention, there is provided a solid-state imaging device in which imaging elements for photoelectrically converting incident light from an object scene are arranged in an array and an obtained imaging signal is output. Means for supplying a drive signal used for driving the generation and readout of the image pickup signal to the image pickup means, and for the readout, a drive signal generating means for generating a drive signal in consideration of a predetermined thinning rate; Control means for generating a control signal for performing signal processing control based on the timing relationship of the drive signal shown; and an image pickup signal read out in consideration of a predetermined thinning rate in response to the drive signal and supplied in digital form. A signal processing unit for performing a moving image display or recording signal process in response to a control signal from the control unit on the digital image pickup signal, and a predetermined thinning ratio is indicated to the drive signal generation unit. System control means, wherein the signal processing means performs a contour correction process on the digital imaging signal, performs a video display process, and performs a contour correction process on the digital imaging signal. Recording processing means for performing processing for

In the solid-state imaging device according to the present invention, the system control unit instructs the drive signal generation unit to specify a predetermined thinning ratio, and the drive signal generation unit generates a drive signal in consideration of the predetermined thinning ratio. In response to the drive signal, the imaging means reads out an imaging signal in consideration of a predetermined thinning ratio and converts it into a digital imaging signal, and the control means performs signal processing control based on the supplied timing relationship. A control signal to be generated is output to the signal processing means, and the digital image pickup signal supplied by the signal processing means is processed in response to a control signal from the control means, and a signal processing for moving image display or contour correction processing and recording is performed. Signal processing for moving image processing and recording processing means respectively. In association with the thinning ratio is prevented degradation in image quality appropriately subjected to correction processing.

Further, in order to solve the above-mentioned problem, the image processing method of the present invention performs signal processing on an image signal which is thinned out at a predetermined thinning rate among image signals obtained from all pixels representing an image. In the image processing method to be performed, the method includes a first step of supplying a predetermined thinning rate as a first control signal, and a drive signal of an operation timing in consideration of the predetermined thinning rate in accordance with the first control signal. A third step of generating an image signal by photoelectric conversion in response to the drive signal, and obtaining a predetermined thinning rate of all the generated image signals in accordance with the drive signal. A fourth step of outputting the obtained image signal as a digital image pickup signal, a fifth step of generating a second or third control signal for performing contour correction based on the timing of the drive signal, Second or third is supplied to the image signal
And a sixth step of performing contour correction processing in the moving image display mode or the recording processing mode in accordance with the control signal.

According to the image processing method of the present invention, a first control signal is output in response to a predetermined thinning rate, and various drive signals of operation timings are considered in accordance with the first control signal in consideration of the predetermined thinning rate. Generating an image signal from the photoelectric conversion in response to the drive signal, and among the generated image signals, an image signal obtained at a predetermined thinning rate in accordance with the drive signal is output as a digital imaging signal. Generating a second or third control signal for performing contour correction based on the timing of a drive signal, and according to the second or third control signal supplied to the digital imaging signal, a moving image display mode or a recording processing mode, respectively. By performing the contour correction processing of
Even when reading is performed at a frame rate corresponding to the thinning ratio, image quality correction can be appropriately performed in each mode.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an image processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

In this embodiment, first, the image processing apparatus 10 will be described as a basic configuration of the present invention, and a digital camera 30 to which a solid-state imaging device is applied will be described. Illustrations and descriptions of parts not directly related to the present invention are omitted. Here, the reference numerals of the signals are represented by the reference numbers of the connecting lines in which they appear.

As shown in FIG. 1, the image processing apparatus 10
Basically, a system control unit 12, a drive signal generation circuit 14, an image sensor 16, an analog / digital conversion unit (ADC: Analog
toDigital Converter) 18, a contour correction control circuit 20, and a signal processing unit 22. It is desirable to dispose an optical system 16a on the incident light side of the image sensor 16.

The system control unit 12 includes, for example, a CPU (Cent
ral Processing Unit). Although not shown, the system control unit 12 includes a ROM (Read Only Memory) in which an operation procedure of the image processing apparatus 10 is written. The system control unit 12, for example,
A control signal 102 for controlling the operation of each unit is generated using information 100 supplied from an operation unit (not shown) in response to a user operation and information (not shown) in the ROM. The information 100 also includes setting information indicating a thinning ratio.

The drive signal generation circuit 14 includes a timing generation circuit and a driver circuit (not shown).
The timing generation circuit is supplied with a clock used as a reference for operation from a signal generation circuit (not shown). The timing generation circuit controls the supplied clock and control signal 10
Various timing signals are generated based on 2. These timing signals include a field shift gate pulse,
A vertical transfer pulse, a horizontal transfer pulse, and the like are included. The timing generation circuit supplies the generated timing signal 104 to the driver circuit and the contour correction control circuit 20. The driver circuit receives the timing signal and converts the timing signal into a driving signal of each level used in the image sensor 16. The drive signal generation circuit 14 outputs these drive signals 106 to the image sensor 16
To supply.

The image pickup device 16 includes a CCD (Charge Coupled D)
evice: charge coupled device (MOS) or MOS (Metal Oxide Semiconduc)
A solid-state imaging device of the tor: metal oxide semiconductor type is applied in an array. In the image sensor 16, the signal charge obtained by the photoelectric conversion in accordance with the supplied drive signal 106 is read into the vertical transfer path by a field shift at a predetermined timing, for example, during the OFF period of the electronic shutter in the signal reading period. The signal charge obtained by line shifting the vertical transfer path is supplied to a horizontal transfer path, and the signal charge passing through the horizontal transfer path is transferred to a charge / output by an output circuit (not shown).
The voltage is converted to an analog voltage signal 108, and the ADC 18
Is output to The image sensor 16 is a CCD type, and performs pixel thinning-out reading and all-pixel reading in accordance with a signal charge reading mode.

It is preferable that an optical low-pass filter and a color filter are integrally provided on the incident light side of the image sensor 16.

The ADC 18 has a function of converting an analog voltage signal 108 output from the image sensor 16 into digital image data. ADC 18 converts the digital image data
110 is supplied to the signal processing unit 22. Although not shown, a correlated double sampling circuit (CDS: Correlated Doppler) for removing a noise component included in the analog voltage signal 108 is provided at a stage preceding the ADC 18.
Double Sampling) should be installed. For example, using a CCD type image pickup device, there is basically provided a clamp circuit that clamps various kinds of noise generated by the device by a timing signal from a timing generator, and a sample hold circuit that holds the signal by the timing signal.

Although not shown, the contour correction control circuit 20 includes a thinning ratio extraction unit and a correction control unit. The thinning-out ratio extracting unit receives the timing signal 104 supplied from the drive signal generation circuit 14 and extracts the thinning-out ratio included in the timing signal 104. For the extraction, for example, a field shift gate pulse is used for the thinning, and the thinning ratio extraction unit checks the supply interval of this pulse in the vertical / horizontal direction to obtain the thinning ratio. That is, in the case of the vertical direction, the thinning rate is obtained from the row interval to which the pulse is supplied when viewed in the column direction of the image sensor 16, and in the case of the horizontal direction, the thinning ratio is obtained from the column interval to which the pulse is supplied when viewed in the row direction of the image sensor 16. Can be

The correction control section has a function of generating correction control signals 112 and 114 to be supplied to the signal processing section 22. The correction control unit generates correction control signals 112 and 114 according to the configuration of the contour correction process employed in the signal processing unit 22.

The signal processing section 22 includes a moving image processing circuit 220 and a recording processing circuit 222. Signal processing unit 2 in FIG.
Reference numeral 2 denotes, before the branch point 116 of the input signal supplied to both the moving image processing circuit 220 and the recording processing circuit 222, although not shown, data correction and color difference matrix processing have already been performed. The moving image processing circuit 220 and the recording processing circuit 222 are supplied with a signal 118 of luminance data Y and color difference data C _r and C _b and correction control signals 112 and 114, respectively.

The moving image processing circuit 220 and the recording processing circuit 222 include the contour correction processing circuit 24 shown in FIG. The contour correction processing circuit 24 includes a contour extraction filter 240, a gain adjustment unit 242, and an adder 244. 2 shows a case where the contour correction processing circuit 24 is provided in the moving image processing circuit 220.

The contour extraction filter 240 uses a band pass filter (BPF). As the predetermined thinning ratio, for example, no thinning, predetermined half, 1 /
Three types of BPFs may be provided corresponding to the case of 4. In this case, the correction control signal 112 becomes a filter selection signal. Further, digital filters corresponding to these three types may be provided, and the correction control signal 112 may be supplied so that the coefficient of each tap is read from the table and set.

In this case, the predetermined thinning ratio is merely three in the above case, but it is needless to say that the present invention is not limited to this. This is because the condition for defining the thinning ratio is determined by the pixel arrangement, the color arrangement of the color filter segments, and the reading of the signal charges in the thinning element.

Since the frequency at which the aliasing distortion occurs differs depending on the thinning ratio, the contour extraction filter 240 is selected in consideration of the filter characteristics so that the aliasing component is not emphasized. Further, the contour extraction filter 240 is changed to perform contour extraction only in the horizontal direction when thinning-out reading is performed in the vertical direction from the image sensor 16. This is because the digital image data 110 in the vertical direction is affected by the thinning distortion, so that the outline correction is performed only in the horizontal direction. The contour extraction filter 240 supplies the component 120 whose contour has been extracted to the gain adjustment unit 242.

The gain adjuster 242 sets the gain in response to the correction control signal 112 and adjusts the strength of the contour correction.
In this adjustment, since the influence of aliasing distortion increases as the thinning ratio increases, it is preferable to adjust the gain to a low gain so that the aliasing component is not emphasized in this tendency. Gain adjusting section 242 outputs gain-adjusted component 122 to adder 244.

The adder 244 inputs the signal 118 of the luminance data Y and the chrominance data C _r and C _b to the terminal 244a, and inputs the gain-adjusted component 122 to the terminal 244b. Although not shown, the input timing is adjusted so that image data at the same position in the image is added. The component 122 in the adder 244 is used as image data after the contour correction.

Returning to FIG. 1, the moving image processing circuit 220 includes an outline correction processing circuit 24, an RGB conversion circuit (not shown) and a D / A conversion unit. Contour correction processing circuit 24, a digital image (luminance data Y and contour correction, color difference data C _r,
C _b ) is supplied to an RGB conversion circuit. The RGB conversion circuit converts the digital image into RGB data having a size corresponding to the screen configuration of a monitor (not shown) and supplies the RGB data to the D / A unit. The D / A unit converts the supplied RGB data into an analog signal 126 and outputs it.

The recording processing circuit 222 includes a contour correction processing circuit, a compression / decompression unit, and a storage unit (not shown). The contour correction processing circuit is a moving image processing circuit 220.
And performs contour correction in response to a correction control signal 114 supplied for recording.
The contour correction processing circuit supplies the digital image whose contour has been corrected to the compression / decompression unit. The compression / decompression unit performs compression processing on the supplied digital image. The compression / decompression unit performs, for example, JPEG (Joint Photographic image co
The compression circuit includes a compression circuit that performs processing on a digital image according to the ding Experts Group) standard and a decompression circuit that performs expansion processing on a digital image that has been compressed according to the standard described above. The compression / decompression unit supplies the compressed digital image to the storage unit.

The storage section stores digital images compressed using a semiconductor memory such as SmartMedia (registered trademark), for example. The storage unit is not limited to this, and may use an optical recording medium, a magneto-optical recording medium, or a magnetic recording medium. At this time, the storage unit
A recording / reproducing unit required for each recording medium is provided.

With such a configuration, the image processing apparatus 10
Even when a digital image is read at a frame rate corresponding to the thinning ratio, appropriate image quality correction is performed on the digital image in each mode.

Next, the operation of the image processing apparatus 10 will be briefly described (see FIG. 3). After turning on the power, the image processing apparatus 10 receives a preset thinning ratio, and
The control signal 102 is supplied to the drive signal generation circuit 14 at a predetermined thinning rate from step 12 (step S10).

The drive signal generation circuit 14 generates various drive signals at operation timings in consideration of a predetermined thinning rate in accordance with the control signal 102 (step S12). The drive signal 106 is supplied to the image sensor 16. Further, the drive signal generation circuit 14
The timing signal 104 used to generate the drive signal is supplied to the contour correction control circuit 20.

Next, the incident light incident via the optical system 16a is photoelectrically converted by the image pickup device 16. This photoelectric conversion period corresponds to an exposure period. The imaging element 16 reads the imaging signal as an image signal in response to the drive signal 106 (imaging: step S14). In reading out the image pickup signal, the signal charges accumulated in each image pickup element are field-shifted to the vertical transfer path according to the thinning ratio. The image sensor 16 transfers the signal charges read out to the vertical transfer path toward the horizontal transfer path according to the vertical drive signal. Further, in the image sensor 16, the signal charges from the vertical transfer path are line-shifted and supplied to the horizontal transfer path, and the horizontal transfer path is transferred toward the output amplifier. The output amplifier performs charge / voltage conversion on the signal charges and outputs an analog voltage signal (imaging signal) 108 to the ADC 18.

The ADC 18 converts the supplied analog voltage signal 108, which is an image signal corresponding to the thinning rate, into a digital signal (step S16). As a result, the digital image data 110 is supplied from the ADC 18 to the signal processing unit 22.

On the other hand, the contour correction control circuit 20 receives the timing signal 104 and generates correction control signals 112 and 114 for performing optimal contour correction based on the timing signal 104 (step S18). For this generation, a thinning-out ratio is obtained from a timing signal by a thinning-out ratio extracting unit. The correction control unit generates correction control signals 112 and 114 for controlling the degree of contour correction in accordance with the obtained thinning ratio. Correction control signal generated by contour correction control circuit 20
112 and 114 are supplied to the moving image processing circuit 220 and the recording processing circuit 222, respectively. The moving image processing circuit 220 and the recording processing circuit 222 may be supplied at the same time to operate, but in this embodiment, one of the two modes is operated.

The signal processing unit 22 performs data correction processing such as gamma correction and white balance adjustment on the supplied digital image data 110, and performs matrix processing on the data-corrected image signal ( Step S20). An image signal supplied by the matrix processing is the luminance data Y and color difference data C _r, the signal 118 converted into C _b. The signal 118 is supplied to the moving image processing circuit 220 and the recording processing circuit 222, respectively.

Next, the mode of the signal processing section 22 is determined (step S22). Correction control signal 11 to video processing circuit 220
If 2 is supplied (YES), the mode is determined to be the video processing mode,
Proceed to step S24. If the correction control signal 114 is supplied to the recording processing circuit 222 (NO), the process proceeds to step S26.
In steps S24 and S26, contour correction processing in each mode is performed.
The characteristics of the contour extraction filter are made different according to the thinning rate, and the gain is adjusted so that the gain decreases as the thinning rate increases. The contour extraction filter is controlled so as to lower the frequency of the BPF in accordance with the thinning ratio and to make the aliasing distortion inconspicuous.

In the moving image mode, the digital image data (brightness data Y and color difference data C _r , C _b ) whose contours have been corrected are R
After performing GB conversion into RGB data, D / A conversion processing is performed on the RGB data to output an analog signal 126 to a monitor (display: step S28).

In the recording mode, digital image data (luminance data Y and color difference data C _r , C _r ,
_b ) is subjected to compression processing and recorded on the recording medium of the storage unit (compression / recording: step S30).

Next, after the display is completed (step S28), it is determined whether or not there is an instruction to perform the processing in the recording mode (step S3).
2). When the correction control signal 114 is supplied to the recording processing circuit 222 (YES), steps S26 and S30 are sequentially performed via the connector A. If the correction control signal 114 has not been supplied after the predetermined time (NO), the image processing is terminated only by the moving image processing.

Next, after the recording process is completed (step S30),
It is determined whether there is an instruction to perform the processing in the moving image mode (step S34). When the correction control signal 112 is supplied to the moving image processing circuit 220 (YES), steps S24 and S28 are sequentially performed via the connector B. If the correction control signal 112 has not been supplied after the predetermined time (NO), the image processing is terminated only by the recording processing.

As described above, in the image processing in each mode, the contour of the image is corrected according to the thinning ratio to prevent the image from being deteriorated.

Next, a modified example of the above-described image processing apparatus 10 will be briefly described. This embodiment has a configuration in which a distortion reduction circuit 246 is newly added to the contour correction processing circuit 24 used in the previous embodiment. Components common to the previous embodiment include:
The same reference numerals are given and the description is omitted. Distortion reduction circuit 24
For 6, a low-pass filter or the like is used. The supplied luminance data Y and color difference data C _r, since it increases in proportion to the thinning effects of aliasing distortion due to read decimated digital image data 118 including the C _b, be eliminated aliasing in accordance with the thinning ratio desired.

The contour correction processing circuit 24 of this embodiment also receives the correction control signal 112 supplied from the contour correction control circuit 20 to the distortion reduction circuit 246 and receives control. Distortion reduction circuit 246
Changes the characteristics of the filter according to the thinning ratio. The characteristics of the filter are such that the greater the thinning ratio, the stronger the distortion reduction processing. The distortion reduction circuit 246 performs processing based on this tendency on the digital image data 118 and outputs digital image data 128. The image displayed using the image data 128 is blurred due to the influence of the distortion reduction processing. The blurred image data 128 is supplied to the contour extraction filter 240 and the adder 244.

The contour extraction filter 240 extracts the contour component signal 120 from the image data 128 and supplies it to the gain adjustment unit 242. In this case, it goes without saying that the contour extraction filter 240 focuses on the contour extraction function rather than the aliasing distortion. The gain adjustment unit 242 adjusts so as to emphasize the extracted outline component, unlike the case where the outline correction is slightly suppressed due to the influence of the aliasing distortion in the previous embodiment. This is to eliminate the influence of the aliasing distortion reduction processing. As a result, the image data 122 is supplied to the end 244b of the adder 244 as an image with improved blur. The adder 244 adds the image data 128 and the image data 122 and satisfies the frame rate to be read out while reducing the influence of aliasing and reducing the number of false signals.
Is output.

The operation of the present embodiment differs from that of the first embodiment in that the contour correction processing (steps S24 and S26) of the flowchart shown in FIG. , 114, a large gain adjustment may be performed on the signal 120 of the component whose contour has been extracted.

Finally, a digital camera 30 to which the solid-state imaging device of the present invention is applied will be described. The digital camera 30 of FIG. 5 shows a more specific configuration having the same components as the image processing device 10 described above.

The digital camera 30 includes an optical system 32, an operation unit 34, a system control unit 36, a drive signal generation circuit 38, a signal generation unit 40, an aperture adjustment mechanism 42, an imaging unit 44, a preprocessing unit 46, and a signal processing unit. 48, a contour correction control circuit 50, a storage unit 52, and a monitor 54 are included.

These parts will be described sequentially. Optical lens system
32 is configured by combining a plurality of optical lenses, for example. Although not shown, the optical lens system 32 has a zoom mechanism that adjusts the positions of these optical lenses and adjusts the angle of view of the screen according to an operation signal 300 from the operation unit 34, and the distance between the subject and the camera 30. It includes an AF (Automatic Focus) adjustment mechanism that adjusts the focus according to the image. The operation signal 300 is supplied to the system control unit 36 via the system bus 200. The optical lens system 32 is supplied with drive signals for operating these mechanisms from a drive signal generation circuit 38 described later.

The operation section 34 is provided with, for example, a mode changeover switch and an item selection operation section (not shown). The item selection operation unit outputs an operation signal 300 from a cross key or the like for moving a cursor to an item displayed on a monitor screen or selecting an item displayed on the monitor screen, and outputs the operation signal 300 to the system control unit 36 via the system bus 200. The release shutter switch is used in each of a plurality of stages.
A pressing operation for selecting one of the preliminary imaging mode and the main imaging mode can be performed.

The system control unit 36 has, for example, a CPU, and calculates exposure parameters and generates control signals to each unit in accordance with a ROM in which operation procedures are written and various signals supplied to the system control unit 36. ing. System control unit 36
Supplies a control signal 302 corresponding to the operation signal 300 to the drive signal generation circuit 38.

In this case, although not shown, the system control unit 36 controls the AE (Automatic) based on the signal charges photoelectrically converted by the imaging unit 44.
Aperture and exposure time are calculated as exposure parameters as matic exposure (automatic exposure) processing. After the control signal 302 corresponding to the calculated value is supplied to the timing signal generator 380, the drive signal 306 corresponding to the signal 304 from the timing signal generator 380 is supplied from the driver 382 to the aperture adjustment mechanism 42. Is done. Note that the exposure parameter may be calculated by the signal processing unit 48 instead of the system control unit 36. The system control unit 36 generates the control signal 30
8 is also supplied to the drive signal generating circuit 38, the pre-processing unit 46, the signal processing unit 48, the storage unit 52, and the monitor 54, though not explicitly shown, via the system bus 200.

The drive signal generation circuit 38 includes a timing signal generation section 380 and a driver 382. The timing signal generator 380 includes a circuit that uses the system clock 310 supplied from the signal generator 40 and generates various timing signals 420 for operating each unit based on the control signal 308. The timing signal generator 380 supplies the generated timing signal 304 to the driver 382. Driver 382
Is the zoom adjustment mechanism of the optical lens system 32 and AF
In addition to the adjustment mechanism, the drive signal 306 is also supplied to the aperture adjustment mechanism 42 and the imaging unit 44 in accordance with each.

The signal generator 40 generates a system clock 310 by an oscillator (not shown) according to the control from the system controller 36, and supplies the system clock 310 to the timing signal generator 380. The system clock 310
For example, the system control unit 36 via the system bus 200
And the signal processing section 48 as operation timing.

The aperture adjustment mechanism 42 is a mechanism for adjusting the cross-sectional area of the incident light beam (that is, the aperture opening area) so as to supply the optimal light beam of the incident light to the image pickup section 44 in photographing the subject. A drive signal is also supplied from the drive signal generation circuit 38 to the aperture adjustment mechanism 42. This drive signal is a signal for an operation performed in accordance with the control from the system control unit 36 described above.

The imaging unit 44 includes an optical low-pass filter 44
a, a color filter 44b and an image sensor 44c.
The imaging element 44c is arranged such that the photoelectric conversion devices are arranged in an array, and a plane (imaging plane) orthogonal to the optical axis of the optical lens system 32 is formed. On the incident light side of the image sensor, an optical low-pass filter 44a and a color filter 4a are provided.
4b is integrally formed. Optical low-pass filter 44
“a” is an optical member having a function of limiting the spatial frequency of an optical image to a Nyquist frequency or lower corresponding to each image sensor, and the color filter 44b is an optical member having a function of color-separating incident light. In this embodiment, imaging is performed using a single-plate type color filter.

As described above, the imaging device 44c has a CCD or
A MOS type solid-state imaging device is applied. Imaging unit 44
Then, the signal charge obtained by the photoelectric conversion in accordance with the supplied drive signal 306 is read as a predetermined timing, for example, by a field shift during the off period of the electronic shutter in the signal readout period to the vertical transfer path. A signal charge obtained by line-shifting the vertical transfer path is supplied to a horizontal transfer path, and the signal charge passing through the horizontal transfer path is converted into an analog voltage signal 31 by charge / voltage conversion by an output circuit (not shown).
It is set to 2 and output to the pre-processing unit 46. In the case of the CCD type, the image pickup section 44 performs pixel thinning-out reading and all-pixel reading in accordance with a signal charge reading mode.

The pre-processing section 46 includes a CDS section and an A / D conversion section (not shown). It is the same component as the image processing device 10. The preprocessing unit 46 outputs the digital image data 314 converted by the A / D conversion unit to the signal processing unit 48 via the system bus 200.

Although not shown, the image data 314 may be temporarily stored in a non-destructive type frame memory and the data may be repeatedly read.

The signal processing section 48 includes a data correction section 480, a color difference matrix section 482, a moving image processing circuit 484, and a recording processing circuit 48.
6 are included. Data correction unit 480, color difference matrix unit
The 482 and the moving image processing circuit 484 are the same components as those of the image processing apparatus 10, and therefore, description thereof will be omitted to avoid complication. The recording processing circuit 486 is different only in that a storage unit is separately prepared. Image data 316 is supplied to the signal processing unit 48 via the system bus 200. The image data 316 is subjected to data correction processing and chrominance matrix processing to generate luminance data Y and chrominance data C _r ,
Image data 318 of the C _b are respectively supplied to the video processing circuit 484 and the recording processing circuit 486.

Moving picture processing circuit 484 and recording processing circuit 486
Performs contour correction processing according to the correction control signals 320 and 322 from the contour correction control circuit 50. The moving image processing circuit 484 outputs an analog RGB signal 324 generated by performing RGB conversion processing and D / A conversion processing on the image data subjected to the contour correction to the monitor 54 via the system bus 200. The recording processing circuit 486 performs compression processing on the contour-corrected image data, and
6 is output to the storage unit 52 via the system bus 200.

The contour correction control unit 50 calculates the thinning ratio using the timing signal 328 supplied from the timing signal generating unit 380, and calculates the moving image processing circuit 484 and the recording processing circuit 486.
Are generated and output to the moving image processing circuit 484 and the recording processing circuit 486, respectively.

As described in the above embodiment, the storage section 52 is preferably a semiconductor memory or the like as a recording medium.
In the case of performing large-capacity recording, for example, an optical disk or the like is used, and a storage unit 52 is provided with a modulation unit for modulating image data and a head used for writing / reading image data.

The monitor 54 uses, for example, a liquid crystal display device with a backlight. The monitor 54 is a system control unit 36
Has a function of considering the size of the screen, adjusting the timing, and displaying the image signal supplied via the system bus 200 in accordance with the above control.

The operation of the digital camera 30 is basically performed according to the flowchart of FIG. However, the digital camera 30 performs preliminary imaging and main imaging by a stroke accompanying a pressing operation of the release shutter button.
After displaying the captured image on the monitor 54 in the former imaging, and displaying it on the monitor 54 in the latter imaging,
The image data is recorded on the recording medium of the storage unit 52.

With this configuration, even in the digital camera 30, even when thinning is performed so as to match the frame rate when reading out the image pickup signal from the image pickup device, the influence of aliasing distortion is suppressed, and the contour is set so that image quality does not deteriorate. By performing the correction processing, it is possible to display and record an image with few false signals.

With the above configuration, an image sensor having a high number of pixels is provided, and aliasing caused by thinning out and reading out an image signal at a predetermined frame rate without impairing smoothness when displaying a moving image is provided. The contour correction processing is performed in each mode so as to avoid a factor of image quality deterioration such as distortion and a decrease in resolution, and particularly, high-quality display in a moving image can be performed.

[0073]

As described above, according to the image processing apparatus and the solid-state imaging device of the present invention, the system control unit instructs the drive signal generation unit to specify the predetermined thinning ratio, and the drive signal generation unit also considers the predetermined thinning ratio. Generated drive signal,
The imaging means and the control means are supplied to the imaging means, respectively. The imaging means reads out an imaging signal in consideration of a predetermined thinning ratio in response to the drive signal, converts the read out imaging signal into a digital imaging signal, and the control means generates a control signal for performing signal processing control. And outputs the signal to the signal processing means. The digital image signal supplied from the signal processing means is subjected to contour correction processing and signal processing for moving image display or contour correction processing and signal processing for recording in response to a control signal from the control means. The moving image processing means and the recording processing means respectively perform the contour correction processing for moving image display or recording on the digital image pickup signal to prevent the image quality from deteriorating according to the thinning ratio, thereby satisfying the read frame rate. It is possible to provide images with little influence of aliasing distortion and few false signals, especially for high-quality display in video processing. To.

Further, according to the image processing method of the present invention,
A first control signal is output in response to the predetermined thinning rate, and various drive signals having operation timings in consideration of the predetermined thinning rate are generated in accordance with the first control signal. Generating an image signal, outputting an image signal obtained at a predetermined thinning rate as a digital imaging signal,
On the other hand, a second or third control signal for performing contour correction based on the timing of the drive signal is generated, and a moving image display mode or a recording process is performed in accordance with the second or third control signal supplied to the digital imaging signal. By performing the contour correction processing of the mode and performing the image quality correction appropriately in each mode even when reading at the frame rate according to the thinning ratio,
It is possible to provide an image with less influence of aliasing distortion and less false signals while satisfying the frame rate to be read, and it is particularly effective for high-quality display in moving image processing.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a basic configuration of an image processing apparatus according to the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of an outline correction processing circuit used in each of the moving image processing circuit and the recording processing circuit of FIG. 1;

FIG. 3 is a flowchart illustrating an operation procedure of the image processing apparatus of FIG. 1;

FIG. 4 is a block diagram illustrating a schematic configuration of a modification of the contour correction processing circuit of FIG. 2;

FIG. 5 is a block diagram illustrating a schematic configuration of a digital camera to which the solid-state imaging device according to the invention is applied.

[Explanation of symbols]

 10 Image processing device 12, 36 System controller 14, 38 Drive signal generator 16, 44c Image sensor 18 A / D converter (ADC) 20, 50 Contour correction controller 22, 48 Signal processor 220, 484 Video processor 222, 486 Recording processing circuit 240 Contour extraction filter 242 Gain adjustment unit 244 Adder 246 Distortion reduction circuit

Claims (19)

[Claims] 1. An image processing apparatus for performing signal processing on an image signal thinned out at a predetermined thinning ratio among image signals obtained from all pixels representing an image, the apparatus comprising: An imaging unit that outputs an imaging signal obtained by photoelectric conversion, and a driving signal used for driving the generation and reading of the imaging signal is supplied to the imaging unit, and the reading is performed in consideration of the predetermined thinning ratio. Drive signal generating means for generating a control signal for performing signal processing control based on a timing relationship of the drive signal indicating the predetermined thinning rate; and the predetermined thinning in response to the drive signal. The imaging signal read out in consideration of the ratio is supplied as a digital signal, and the digital imaging signal is displayed or recorded in response to a control signal from the control means. Signal processing means for performing signal processing of the following, and system control means for instructing the predetermined thinning ratio to the drive signal generation means, wherein the signal processing means performs contour correction processing on the digital imaging signal, and displays a moving image. An image processing apparatus comprising: moving image processing means for performing processing for image processing; and recording processing means for performing contour correction processing on the digital imaging signal and performing processing for recording. 2. The apparatus according to claim 1, wherein each of the moving image processing means and the recording processing means includes a filter for extracting a contour component of an image included in the supplied digital image pickup signal, and the extracted contour. An image processing apparatus, comprising: a gain adjustment unit that adjusts the intensity of gain correction for a component; and a unit that adds the digital imaging signal and the gain-corrected contour component. 3. The apparatus according to claim 1, wherein each of the moving image processing means and the recording processing means performs horizontal contour extraction on a digital image signal which has been decimated and read in a vertical direction. An image processing apparatus characterized by the above-mentioned. 4. The apparatus according to claim 1, wherein each of the moving image processing unit and the recording processing unit changes a filter characteristic of the filter according to the thinning ratio. apparatus. 5. The image processing apparatus according to claim 3, wherein each of the moving image processing unit and the recording processing unit changes a filter characteristic of the filter according to the predetermined thinning ratio. apparatus. 6. The apparatus according to claim 1, wherein the control unit performs the thinning-out reading in the vertical direction and the predetermined thinning-out ratio and / or the gain in accordance with the magnitude of the gain. An image processing device for generating a control signal. 7. The apparatus according to claim 1, further comprising: a distortion suppression unit configured to reduce distortion generated in the digital imaging signal due to thinning-out reading. An image processing apparatus for supplying an output signal of the means to the signal processing means. 8. An image pickup device for arranging an image pickup device for photoelectrically converting incident light from an object scene to output an obtained image pickup signal, and a drive signal used for generating and reading out the image pickup signal. Is supplied to the image pickup means, and the readout is performed by a drive signal generating means for generating a drive signal in consideration of a predetermined thinning rate, and performing signal processing control based on a timing relationship of the drive signal indicating the predetermined thinning rate. Control means for generating a control signal to be applied, and an image pickup signal read in consideration of the predetermined thinning ratio in response to the drive signal is supplied as a digital signal, and the digital image signal is supplied to the control signal from the control means. Signal processing means for performing signal processing for responding moving image display or recording; and system control means for instructing the drive signal generation means for the predetermined thinning ratio. The signal processing unit includes a moving image processing unit that performs an outline correction process on the digital imaging signal and performs a process for displaying a moving image, and a recording processing unit that performs an outline correction process on the digital imaging signal and performs a recording process. A solid-state imaging device characterized by including: 9. The apparatus according to claim 8, wherein each of the moving image processing unit and the recording processing unit extracts a contour component of an image included in the supplied digital image pickup signal; A solid-state imaging device comprising: a gain adjustment unit that adjusts the intensity of gain correction for a component; and a unit that adds the digital imaging signal and the gain-corrected contour component. 10. The apparatus according to claim 8, wherein each of the moving image processing means and the recording processing means performs horizontal contour extraction on a digital image signal which has been decimated and read in the vertical direction. A solid-state imaging device characterized by the above-mentioned. 11. The apparatus according to claim 8, wherein each of the moving image processing unit and the recording processing unit changes a filter characteristic of the filter according to the predetermined thinning ratio. Solid-state imaging device. 12. The solid-state imaging device according to claim 11, wherein each of the moving image processing unit and the recording processing unit changes a filter characteristic of the filter according to the predetermined thinning ratio. apparatus. 13. The apparatus according to claim 8, wherein the control means controls the control signal according to the thinning-out reading in the vertical direction, the thinning-out ratio and / or the magnitude of the gain. A solid-state imaging device characterized by generating: 14. The apparatus according to claim 8, further comprising: a distortion suppression unit configured to reduce distortion generated in the digital imaging signal due to thinning-out reading. A solid-state imaging device for supplying an output signal of the means to the signal processing means. 15. An image processing method for performing signal processing on an image signal thinned out at a predetermined thinning rate among image signals obtained from all pixels representing an image, the method comprising: A first step of supplying as a first control signal; a second step of generating various drive signals of operation timing in consideration of the predetermined thinning rate in accordance with the first control signal; A third step of responsively generating the image signal by photoelectric conversion, and outputting, as a digital imaging signal, an image signal obtained at the predetermined thinning ratio according to the drive signal, out of all the generated image signals. A fourth step of generating a second or third control signal for performing contour correction based on the timing of the drive signal, and a second step of supplying the digital imaging signal. Or a sixth step of performing contour correction processing in a moving image display mode or a recording processing mode in response to a third control signal, respectively. 16. The method according to claim 15, wherein in the contour correction processing, horizontal contour extraction is performed on a digital image signal read when the predetermined thinning is performed in a vertical direction. An image processing method comprising: 17. The image processing method according to claim 15, wherein the contour correction process changes a filter characteristic according to the predetermined thinning ratio. 18. The image processing method according to claim 16, wherein the contour correction process changes a filter characteristic according to the predetermined thinning ratio. 19. The method according to claim 15, wherein the digital imaging signal is subjected to a decimated readout before being supplied to a sixth step. An image processing method, comprising: performing a distortion suppression process to reduce the height; and adjusting the contour correction process in a direction to enhance the contour correction process in a sixth step.