JPH06261333A - Imaging device - Google Patents

Abstract

(57) [Summary] [Purpose] When a subject is divided into multiple areas for shooting, and the video signals in each area are combined to create a composite video, the effect of the saturation and brightness of the specific area is affected. The present invention provides an imaging device that can appropriately correct a composite video signal. A plurality of divided areas of a subject are photographed by an image pickup means including an optical lens 1 and an image pickup element 2, and a video signal of each of the thus photographed areas is AD.
It is stored in the memory 6 via the converter 5 and is also input to the integrator 15. Then, according to the integrated value of the image of the entire region from the integrator 15, the system controller 13 creates a control voltage for performing correction based on the image characteristics of all video signals in each region, and the DSP 14 generates the control voltage. Based on the above, the white balance correction and the brightness correction of the combined video signal read out from the memory 6 are appropriately performed, and a high quality photographed image is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus which obtains a high-definition image or a panoramic image by dividing a subject into a plurality of regions, photographing the subject, and synthesizing video signals in the respective regions.

[0002]

2. Description of the Related Art A so-called image synthesizing camera is known which divides a subject into a plurality of areas and synthesizes video signals obtained by photographing the divided areas to create a high-definition image or a panoramic image. FIG. 4 is a block diagram showing a configuration of an image synthesizing camera as a conventional image pickup apparatus of this type, and FIG.
It is a figure explaining an example of division of a subject at the time of photography with this image composition camera. The image synthesizing camera shown in FIG. 4 includes an optical lens 1, an image sensor 2, a sample hold circuit 3, a signal processing circuit 4, an A / D converter 5, a memory controller 7, a DSP 8, a D / A converter 9, and a recording circuit 10. , A recording medium 11 such as a magnetic disk is connected in this order, and a memory 6 is connected to the memory controller 7. Further, a synchronization signal generation circuit 12 and a system controller 13 to which a colorimetric sensor 14 is connected are provided, and the synchronization signal generation circuit 12 synchronizes the operation of each part such as a sample hold pulse and a clamp pulse. The clock is output and supplied to each unit. In addition, the system controller 13
Calculates the white balance correction value and the brightness correction value based on the color temperature of the external light detected by the color measurement sensor 14, and controls the overall operation of the image synthesizing camera.

In photographing, as shown in FIG. 5, the subject is divided into nine regions I to IX, and in consideration of the fact that the main part of the subject is often in the center of the photographing frame, the photographing is performed. The order is set to, for example, region V, region IV, region VI, region II, region VIII, region I, region III, region VII, region IX. First, the area V is photographed by directing the optical lens 1 of FIG. 4 toward the area V of the subject, an optical image of the area V of the subject is formed on the imaging surface of the image sensor 2, and the optical image is photoelectrically converted. An electric signal corresponding to the region V of the subject is output from the image sensor 2. The electric signal is input to the sample hold circuit 3, and the sample hold circuit 3 outputs a video signal corresponding to the region V of the subject.

This video signal is input to the signal processing circuit 4, and in the signal processing circuit 4, the color temperature of the external light input from the colorimetric sensor 14 is input to the video signal by a command signal from the system controller 13. The white balance (WB) correction is performed corresponding to, and the brightness correction and the γ conversion are further performed. The video signal subjected to the white balance correction, the brightness correction and the γ conversion in this manner is AD-converted into a digital signal by the AD converter 5 and input to the memory controller 7. Then, it is stored in a predetermined area of the memory 6 by the memory controller 7.

Next, the area IV is photographed by directing the optical lens 1 toward the area IV of the subject, and in the same manner as the case of the area V,
White balance correction, luminance correction, and γ conversion are performed on the video signal corresponding to the area IV of the subject, AD conversion is performed, and the result is stored in a predetermined area of the memory 6. And so on
VI, area II, area VIII, area I, area III, area VII, and area IX are sequentially stored in the memory 6 in order of the image signal of the object, and the object 6 corresponding to the entire area of the object is stored. The video signal is stored in the memory 6.

When the storage of the video signal of each area of the subject in the memory 6 is completed in this way, a video signal of the entire subject is generated based on the video signal corresponding to each area by a command signal from the memory controller 7. Are combined, and the combined video signal is output from the memory controller 7,
The DSP 8 processes the digital signal into a predetermined format. The video signal thus signal-processed is DA-converted into an analog signal by the DA converter 9, converted into a predetermined format by the recording processing circuit 10, and recorded on the recording medium 11.

In this conventional image synthesizing camera, it is desirable that the AE (automatic exposure) level and the white balance level of the video signals corresponding to the respective areas are all the same, so that the AE level and the white balance of the first area V are set. The correction value of each area after the area VI is set according to the level.

[0008]

The above-mentioned conventional image synthesizing camera requires a colorimetric sensor for measuring the color temperature of external light for white balance correction. The use of this colorimetric sensor reduces the manufacturing cost. However, there is a problem that the increase in the number of cameras and the miniaturization of the entire camera are hindered. In this case, it is conceivable to adopt the TTL method in which the white balance adjustment is performed by the output of the image sensor without using the colorimetric sensor, but the white balance adjustment is performed for each shooting of each area, and the white balance adjustment is performed for each area. Due to the video signal, the white balance state varies between areas. In order to prevent this, for example, it is conceivable to obtain a white balance control value in the first region V and use the control value fixed thereafter. However, in this case, the control value of the white balance largely depends on the color of the flower occupying most of the area V, and the control that correctly corresponds to the color temperature of the external color is not performed. In the case of FIG. 5, if the color of the flower is red, it is determined that the external color is the low color temperature light source,
It will be corrected in blue more than necessary.

This also applies to the brightness correction for the AE adjustment. For example, if a low brightness object occupies a large part in the area V photographed first, it is affected as a whole and as a whole. It will be overexposed considerably.

The present invention has been made in view of the current state of signal processing in such an image pickup apparatus as described above, and an object thereof is to divide a subject into a plurality of regions and photograph them so that each region is photographed. An object of the present invention is to provide an imaging device capable of performing appropriate correction processing on a composite video signal without being affected by the saturation and luminance of a specific area when the video signals are composited to create a composite video. .

[0011]

In order to achieve the above-mentioned object, the present invention provides an image pickup means for taking an image by dividing a subject into a plurality of areas and an image signal of each area output from the image pickup means. In an image pickup apparatus comprising a storage unit for storing and a synthesizing unit for creating a composite video signal by synthesizing the video signals of the respective stored regions, in at least two regions of the plurality of photographed regions It is characterized in that it has a correction means for correcting the composite video signal based on the image characteristics of the video signal.

[0012]

With the above structure, the image pickup means photographs the subject in each of the plurality of areas, and the video signals of the photographed areas are stored in the storage means. Then, the synthesizing means synthesizes the video signals in the respective areas to create a synthetic video signal, and the correcting means appropriately corrects the synthetic video signals based on the image characteristics of all the video signals in the areas. The high quality photographed image is obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a block diagram showing the structure of the first embodiment. This first embodiment is already shown in FIG.
In comparison with the configuration of the conventional image synthesizing camera described with reference to FIG. 1, the signal processing circuit 4 is removed, and instead of the DSP 8, a DSP 14 that performs signal processing including white balance correction, brightness correction, and γ conversion is used as a memory controller 7 and a DA. The output terminal of the sample hold circuit 3 is provided between the converter 9 and the converter 9, and is connected to the system controller 13 via the integrator 15. Since the configuration of the other parts of the first embodiment is the same as that of the conventional image synthesizing camera described above,
In FIG. 1, elements corresponding to those in FIG. 4 are designated by the same reference numerals.

Next, the operation of the first embodiment will be described. In the following description, as in the case of the conventional image synthesizing camera described above, as shown in FIG.
Divided into 9 areas of area IX, the main part of the subject is the shooting frame F
Considering that it is often located at the center of the image, the order of shooting is, for example, region V, region IV, region VI, region II, region VII.
It is assumed that I, region I, region III, region VII, and region IX are set.

First, the optical lens 1 is directed to the area V,
The video signal corresponding to the optical image of the region V of the subject formed on the image pickup surface of the image pickup device 2 by the optical lens 1 is output from the sample hold circuit 3 as an RGB signal and AD-converted by the AD converter 5. The data is input to the memory controller 7 and stored in a predetermined area of the memory 6 according to a command from the memory controller 7. At the same time, the RGB signals are input to the integrator 15, and the RGB signals are integrated in the area V. In the same manner, the video signals corresponding to the respective areas of the subject are sampled and held as the RGB signals in the order of area IV, area VI, area II, area VIII, area I, area III, area VII, and area IX. Is output from the AD converter 5, AD converted by the AD converter 5, and input to the memory controller 7.
The RGB signal is stored in a predetermined area of the memory 6 according to a command from the memory controller 7, and at the same time, the RGB signal is input to the integrator 15, and the RGB signal is integrated for each area.

When the integrator 15 completes the integration in the entire region, the integrated values corresponding to the obtained all captured images are input to the system controller 13, and the system controller 13 outputs R based on the integrated value. The white balance correction value is calculated so that the integrated value of the signal, the G signal, and the B signal becomes 1: 1: 1, and the corresponding white balance control signal is input to the DSP 8. On the other hand, in the memory controller 7, after the output of the white balance control signal, the video signal corresponding to each area of the subject is read from the memory 6, these video signals are combined and input to the DSP 14.

Further, in the system controller 13, 0.3R + 0.59G + 0.11B is calculated as a luminance signal based on the integrated value input from the integrator 15, and this signal level is set to a preset reference value. The brightness correction amount is calculated by comparison, and the corresponding brightness control signal is DS
Input to P14.

Therefore, the DSP 14 performs white balance correction on the composite video signal input from the memory controller 7 by the white balance control signal from the system controller 13 and brightness correction by the luminance control signal. Further, predetermined signal processing such as γ conversion is performed. In this way, the image signal of the subject, which has been subjected to various signal processing including white balance correction and brightness correction, is input to the DA converter 9 and DA converted into an analog signal, and the recording processing circuit 10 formats the image signal in a predetermined format. And is recorded on the recording medium 11.

Thus, according to the first embodiment,
The system controller 13 calculates the white balance correction value and the brightness correction value based on the integrated value of the video signal corresponding to the entire region of the subject, and the DSP 8 corresponds to the white balance correction value and the brightness correction value. With the white balance control signal and the brightness control signal, white balance correction and brightness correction are performed on the composite video signal input from the memory controller 7. For this reason, even if there is a region in which the saturation and luminance are significantly different from the others in the divided region of the subject, the effect is suppressed to a minimum, and proper white balance correction and luminance correction are always performed, resulting in high quality. It becomes possible to obtain high-definition images and panoramic images.

[Second Embodiment] In the second embodiment, the first
In contrast to the above embodiment, the integrator is configured to integrate the weighted video signal for each region. FIG. 2 is a circuit diagram showing the configuration of the integrator 15A of the second embodiment. The non-inverting input terminal of the operational amplifier 16 is grounded, the capacitor 22 is connected between the inverting input terminal and the output terminal, and the operational amplifier 16 is provided. The system controller 13 is connected to the output terminal of the. Further, between the output side of the sample hold circuit 3 and the inverting input terminal of the operational amplifier 16,
A resistor 21, a switch 18 and a resistor 20 connected in series,
A series connection circuit of the switch 17 and the resistor 19 is connected in parallel with each other. The configuration of the other parts of the second embodiment is the same as that of the first embodiment already described, and therefore illustration and description thereof will be omitted.

In the second embodiment, at the time of integration of the video signal of the region V having the highest object existence probability, the switches 17 and 1 are switched by the command signal from the system controller 13.
8 is closed and the gain of the integrator 15A is set to the maximum,
Next, area IV, area VI, area II,
At the time of integration of the video signal in the region VIII, the switch 18 is closed to set a medium gain. Further, when integrating the video signals of the regions I, III, VII, and IX where the subject existence probability is low, the switches 17 and 18 are opened to set the gain to a small value. In this way, the integrator 15A obtains an integrated value of a level corresponding to the existence probability of the subject. The other operations of the second embodiment are the same as those of the first embodiment already described. It should be noted that the gain may be set to 0 according to the conditions of shooting and the subject.

Thus, according to the second embodiment,
In addition to the effect obtained in the first embodiment, the integrator 15A
However, since the integrated value corresponding to the existence probability of the subject is calculated in each region, the accuracy of luminance correction is particularly improved.

[Third Embodiment] In the third embodiment, when the subject has a high saturation portion, the white balance correction is performed by reducing the influence of the high saturation portion. FIG. 3 is a block diagram showing the structure of the third embodiment. This third embodiment is different from the structure of the conventional image synthesizing camera described with reference to FIG.
The second memory 23 is newly connected between the memory controller 7 and the system controller 13, and the inverse γ conversion circuit 24 is newly connected between the signal processing circuit 4 and the DA converter 9.
A direct connection route is newly provided between the DA converter 9 and the DA converter 9. The configuration of the other parts of the third embodiment is the same as that of the conventional image synthesizing camera which has already been described with reference to FIG. 4. Therefore, in FIG. 3, the elements corresponding to FIG. is there.

In the third embodiment, for the video signal from the sample hold circuit 3, the signal processing circuit 4
Temporary white balance correction is performed by a preset gain, the video signal is further γ-converted, AD-converted into a digital signal by the AD converter 5, and stored in the memory 6 and the memory 23 via the memory controller 7. It In this case, in the memory 23, if the level difference between the signal of one pixel before and the signal of one line before is less than or equal to the reference value X, the memory 23 determines that the same color subject is not stored. Further, in the memory 23, when it is determined by the color difference signals R-Y and B-Y output from the DA converter 9 that it is a high saturation part, the reference value X is set to a large value and the same subject is detected. The image-processed video signal is stored with a high probability of judgment.

Then, in the system controller 13,
The video signal stored in the memory 23 is read out, the white balance correction value is calculated based on the integrated value obtained by the addition integration processing, and the corresponding white balance control voltage is output. In this state, by the memory controller 7,
A video signal is read from the memory 6, and this video signal is
The signal is input to the DA converter 9 in the same signal format as the output of the sample and hold circuit 3 without passing through the DSP 8, is DA converted into an analog signal, and is input to the inverse γ circuit 24.

Then, the video signal is inverse-γ converted by the inverse γ circuit 24, input again to the signal processing circuit 4, and white balance correction is performed by the control voltage obtained as described above, and γ converted. It is later input to the AD converter 5. The video signal AD-converted into a digital signal by the AD converter 5 is input to the DSP 8 via the memory controller 7, and the DSP 8 processes the signal into a predetermined format.
The recording medium 1 is DA converted into an analog signal by the converter 9 and converted into a predetermined format by the recording processing circuit 10.
It is recorded in 1.

As described above, according to the third embodiment, the memory 23 omits storing a part of the video signal of the high-saturation portion of the subject, and the system controller 13 causes the memory 23 to store the image signal.
Since the video signals read out from are added and integrated, and the white balance correction is performed based on the obtained integrated value, in addition to the effect obtained in the first embodiment, it is appropriate that the influence of the high saturation part of the subject is reduced. White balance correction is possible.

In each of the above-mentioned embodiments, the case where the subject is photographed in each area by changing the direction of the optical lens has been described, but the present invention is not limited to the above-mentioned embodiments. Alternatively, it is possible to provide a plurality of sets of photographing optical systems each having an optical lens and an image pickup device corresponding to each area, and switch the photographing optical systems to shoot a subject in each area.

[0029]

As described above, according to the present invention, the image pickup means for dividing a subject into a plurality of areas and photographing the image data, and the storage means for storing the image signals of the respective areas outputted from the image pickup means. And a synthesizing means for synthesizing the video signals of the respective stored regions to create a synthetic video signal, in the image pickup device, a video image in at least two or more regions with respect to the plurality of photographed regions. Since the correction means for correcting the composite video signal based on the image characteristics of the signal is included, the white balance correction and the brightness correction appropriate for the composite signal can be performed without being affected by the saturation and the brightness of the specific area. It is possible to perform correction processing such as.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a main part of a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a conventional image synthesizing camera.

FIG. 5 is a diagram illustrating an example of division of a subject.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical lens (imaging means) 2 Imaging element (imaging means) 6 Memory (storage means) 7 Memory controller 13 System controller (correction means) 15, 15A Integrator (correction means) 23 Memory (correction means) 24 Inverse γ conversion circuit

Claims (3)

[Claims] 1. An image pickup device for dividing an object into a plurality of regions and photographing the image data, a storage device for storing the image signal of each region output from the image pickup device, and a video signal for each of the stored regions. In an imaging device including a synthesizing unit that creates a synthesized video signal by synthesizing, the synthetic video signal is corrected based on image characteristics of the video signal in at least two regions of the plurality of photographed regions. An image pickup apparatus comprising: a correction unit for performing. 2. The image pickup apparatus according to claim 1, wherein the correction unit performs white balance correction of the composite video signal. 3. The image pickup apparatus according to claim 1, wherein the correction unit corrects a luminance level of the composite video signal.