JP6932053B2 - Imaging device - Google Patents

Description

The present invention relates to an image pickup apparatus, and particularly in a four-plate type image pickup apparatus using a CMOS image sensor having a small pixel pitch, the degree of modulation in the low frequency range is improved and the degree of modulation in the high frequency range is improved at the time of down conversion. The present invention relates to an image pickup device that can be relatively reduced.

[Explanation of prior art]
CCD (Charge Coupled Device) CDS (Correlated Double Sampling) that removes noise from the signal output from the image pickup element, dark current correction, and variable gain control (AGC), and output to the display device. Therefore, AFE (Analog Front End) with a built-in ADC (Analog Digital Converter) that converts digital video signal Vi has become widespread, and the ADC gradation of AFE, which was 10 bits in the past, is now generally 12 bits or 14 bits. rice field.
In addition, improvements have been made to CMOS (Complementary Metal Oxide Semiconductor) image sensors that enable high-speed readout by integrating drive circuits and readout circuits.

Furthermore, the integration of digital signal processing circuits has progressed, and not only video-dedicated memory-integrated DSPs (Digital Signal Processors) but also inexpensive general-purpose FPGAs (Field Programmable Gate Arrays) can store output signals of multiple lines for arithmetic processing. It has become easier to do.

As a result, a megapixel camera with more than one million pixels, an HDTV (High Definition TeleVision) camera, a high-speed imaging HDTV camera, an HDTV camera with a recording unit, and an HDTV with an Internet Protocol (IP) transmission unit (1080 x) 1920) Cameras, higher definition 4K (2160 x 3840) cameras, 8K (4320 x 7680) cameras and the like have been commercialized, and uncompressed recording devices using HDDs (Hard Disk Drive) have also been commercialized.

[Structure of image sensor: FIG. 17]
Here, the configuration of the image pickup device will be described with reference to FIG. 17A and 17B are cross-sectional explanatory views showing the configuration of an image sensor, in which FIG. 17A is a CCD sensor (image sensor), FIG. 17B is a conventional CMOS sensor (surface-illuminated CMOS image sensor), and FIG. A Back Side Illumination) type CMOS sensor (back side illumination type CMOS image sensor) is shown.
As shown in FIG. 17A, in the CCD sensor, the microlens 91, the color filter 92, and the photodiode 93 are laminated, and a metal wiring layer 94 is formed between the photodiode 93 and the color filter 92. ing.

The incident light collected by the microlens 91 passes through the color filter 92, is decomposed into R (red), G (green), and B (blue) components, and is incident on the photodiode 93 to generate an electric charge. Then, it is transferred in the vertical direction and the horizontal direction and converted into a voltage for each pixel.
Although the CCD sensor has high sensitivity, it consumes a large amount of power, and it is more difficult to integrate peripheral circuits than a CMOS image sensor.

The surface-illuminated CMOS image sensor shown in FIG. 17B has a configuration in which a transistor or the like is provided for each pixel, and although it has low power consumption and is easy to integrate, its sensitivity is low.
The back-illuminated CMOS image sensor shown in FIG. 17C has a metal wiring layer 93 provided on the back surface side of the photodiode 93, and has high sensitivity, low power consumption, and is easy to integrate.

In particular, a general low-priced surface-illuminated CMOS image sensor (4/3 type or less including 1.25 type at 8K or 2/3 type or less at 4K) has a pixel pitch of 5 wavelengths or less and a photodiode 93. Since the metal wiring layer 94 is laminated between the microlens (on-chip lens) 91 and the microlens (on-chip lens) 91, the degree of modulation in the low frequency range is low.

Further, in a four-plate camera having an RG1G2B image sensor that shifts oblique pixels with two green image sensors (G1) and (G2) and having a frame memory, the degree of oblique modulation is low.
Further, if an optical low pass filter (O-LPF; Optical Low Pass Filter) is inserted in order to suppress the moire of the folded false signal of the high frequency component outside the counter frequency, the degree of modulation is further lowered.

Furthermore, in the 2/3 type 4K and 1.25 type 8K, the pixel pitch of the image pickup element is about 2.5 μm, which is about 4.5 times the green wavelength of 0.55 μm, and the aberration of the high-magnification zoom lens is optically reduced. The degree of modulation in the low frequency range (modulation transfer function characteristic: MTF; Modulation Transfer Function) is reduced.

Further, in the conventional video signal processing device, the inclination direction of the contour portion of the video signal is determined. There is a device that generates interpolated pixel data by using a plurality of original pixel data in the video signal according to the determination result of the inclination direction of the contour portion, and generates a video signal in which the number of pixels is increased.

By the way, when down-converting the image of a UHDTV (Ultra High Definition TeleVision) camera to a 1K x 2K HDTV, the 1MHz of the 2K jump scanning HDTV is defined as 100%, which is 27 of the 2K HDTV. It is required to reduce the degree of modulation of 5.5 MHz to 50%.
Moreover, improvement of the modulation degree of a low region is always demanded by a broadcasting station.

Further, in a UHDTV camera using a surface-illuminated CMOS image sensor, it is known that the MTF at a low frequency decreases when the pixel pitch becomes 5 wavelengths or less of the center wavelength of the image pickup light.
For example, in the 2/3 type 4K and 1.25 type 8K image pickup elements, the pixel pitch is about 2.5 um, which is about 4.5 times the green wavelength of 0.55 um, and the aberration of the high magnification zoom lens is optical. The low frequency modulation degree drops because it cannot be corrected to.

[Related technology]
As the prior art relating to the image pickup apparatus, Japanese Patent Application Laid-Open No. 2013-207673 "Video Signal Processing Device and Method" (Patent Document 1) and Japanese Patent Application Laid-Open No. 2007-336384 "Image Processing Device and Method" (Patent Document 2). , International Publication No. 2016/031764, “Image Imaging Device and Imaging Method” (Patent Document 3).

Patent Document 1 describes that the characteristics for generating a high frequency signal component are different depending on the determination result in the inclination direction of the contour portion.
Patent Document 2 describes an image processing apparatus that suppresses moire of oblique aperture correction.
Patent Document 3 describes an imaging device that performs oblique contour correction with four plates of RGGB.

Japanese Unexamined Patent Publication No. 2013-207673 Japanese Unexamined Patent Publication No. 2007-3636384 International Publication No. 2016/031764

As described above, in a conventional image sensor using an image sensor having a pixel pitch of 5 wavelengths or less, when down-converting an image of a UHDTV camera, the degree of modulation in the high range is relative to the degree of modulation in the low range. There was a problem that it was difficult to reduce it.
Further, the conventional image pickup apparatus has a problem that the degree of modulation in the low frequency range is low.

The present invention has been made in view of the above circumstances, and when down-converting an image of a UHDTV camera using an image sensor having a pixel pitch of 5 wavelengths or less, high-frequency modulation is performed with respect to low-frequency modulation. It is an object of the present invention to provide an image pickup device capable of relatively lowering the degree and improving the degree of modulation in the low frequency range.

Above prior art the present invention for solving the problems, the pixel pitch is less than 5 times the center wavelength of the imaging light, red, a blue and two green CMOS imaging element, two green CMOS imaging an imaging apparatus for performing shifting oblique pixel elements, a color separation optical system for decomposing the input light for each color, red for outputting a video signal light decomposed by the color separation optical system photoelectric conversion for each color a color separation unit and a blue and two green CMOS image sensor, an interpolation processing unit for performing an interpolation process based on a signal from the color separation unit, the video signal from the interpolation processing section, was outline correction After that, it has a down converter unit that down-converts and outputs, and the down converter unit has a plurality of video signals of the pixel to be corrected for contour correction and the distance from the pixel to be corrected is 3 pixels or more. The difference from the video signal of the pixel is calculated, the contour correction signal is generated based on the difference addition signal obtained by adding the plurality of differences, and the contour correction signal is added to the video signal of the pixel to be corrected to perform contour correction. It is characterized in that it is provided with a contour correction unit to perform.

Further, in the above-mentioned imaging device, in the above-mentioned imaging device, the contour correction unit adds the video signal of a pixel whose distance from the pixel to be corrected is within 2 pixels to the video signal of the pixel to be corrected, and the addition is performed. It is characterized in that contour correction is performed by calculating the difference between the signal and the video signal of a plurality of pixels having a distance of 3 or more pixels from the pixel to be corrected.

Further, in the above-mentioned imaging device, in the above-mentioned imaging device, the contour correction unit includes a vertical contour correction unit that corrects a vertical contour, a horizontal contour correction unit that corrects a horizontal contour, an upper right diagonal contour, and an upper left diagonal. It is characterized by having an oblique contour correction unit that corrects the contour in the direction.

Further, the present invention is characterized in that, in the image pickup apparatus, the contour correction unit uses pixels having a distance of up to 68 pixels from the correction target pixel in generating the difference addition signal.

According to the present invention, an image pickup device that uses two green CMOS image sensors, red, blue, and two green CMOS image sensors whose pixel pitch is 5 times or less the center wavelength of the image pickup light, and obliquely shifts pixels with two green CMOS image sensors. a is a color separation optical system for decomposing the input light for each color, red for outputting a video signal light decomposed by the color separation optical system photoelectric conversion for each color, blue and two green CMOS imaging a color separation unit having an element, and the interpolation processing unit for performing an interpolation process based on a signal from the color separation unit, the video signal from the interpolation processing section, after the contour correction, down to output the down-converted The down converter unit has a converter unit, and the down converter unit determines the difference between the video signal of the pixel to be corrected for contour correction and the video signal of a plurality of pixels having a distance of 3 or more pixels from the pixel to be corrected. As an image sensor provided with a contour correction unit that calculates and generates a contour correction signal based on the difference addition signal obtained by adding the plurality of differences, and adds the contour correction signal to the video signal of the pixel to be corrected to perform contour correction. Therefore, there is an effect that the degree of modulation of the low range can be improved and the relative degree of modulation of the high range can be reduced by enhancing the ultra-low range and not performing the high range contour correction.

Further, according to the present invention, the contour correction unit adds the video signal of the pixel whose distance from the pixel to be corrected is within 2 pixels to the video signal of the pixel to be corrected, and the added signal and the added signal are added. Since the image pickup device performs contour correction by calculating the difference from the video signal of a plurality of pixels having a distance of 3 pixels or more from the pixel to be corrected, the relative modulation degree in the low frequency range is further reduced. There is an effect that can be done.

Further, according to the present invention, the contour correction unit includes a vertical contour correction unit that corrects the vertical contour, a horizontal contour correction unit that corrects the horizontal contour, an upper right diagonal contour, and an upper left diagonal contour. Since the image pickup device is provided with an oblique contour correction unit for correcting be.

Further, according to the present invention, since the contour correction unit is the image pickup device that uses pixels with a distance of up to 68 pixels from the correction target pixel in the generation of the difference addition signal, it is low without increasing the circuit scale. At cost, it has the effect of improving the degree of modulation in the low frequency range and reducing the relative degree of modulation in the high frequency range.

It is a block diagram which shows the schematic structure of this image pickup apparatus. It is a schematic explanatory drawing which shows the overlapping degree of each pixel of the bonding position of the image pickup element in the image pickup apparatus shown in FIG. It is a schematic explanatory drawing which shows the difference between the oblique resolution and the vertical-horizontal resolution by the oblique interpolation of G1 and G2 of each pixel of the four-plate image sensor. It is a block diagram which shows the structure of the video signal processing unit 104. It is a block diagram of the 1st vertical contour correction part. It is a block diagram of the 1st horizontal contour correction part. It is a schematic explanatory view which shows the outline of the oblique contour correction, (a) shows the upper right oblique contour correction, and (b) shows the upper left oblique contour correction. It is a block diagram of the 1st upper right diagonal contour correction part. It is a block diagram of the 1st upper left diagonal contour correction part. It is a general block diagram of the contour correction part of the 1st image pickup apparatus. It is a block diagram of the 2nd vertical contour correction part. It is a block diagram of the 2nd horizontal contour correction part. It is a block diagram of the 2nd upper right diagonal contour correction part. It is a block diagram of the 2nd upper left diagonal contour correction part. It is explanatory drawing of the signal after contour correction in the 1st and 2nd image pickup apparatus. It is explanatory drawing which shows the modulation degree in the 1st and 2nd image pickup apparatus, (a) is the modulation degree of the 1st image pickup apparatus, (b) is the modulation degree of the pre-correction signal and the contour correction post-correction signal of a 2nd image pickup apparatus. Shown. It is sectional drawing which shows the structure of the image sensor.

Embodiments of the present invention will be described with reference to the drawings.
[Outline of Embodiment]
The image pickup device according to the embodiment of the present invention uses a CMOS image pickup element having a pixel pitch of 5 or less of the center wavelength of the image pickup light, and performs contour correction in an image pickup device in which two green image pickup elements shift diagonal pixels. Peripheral pixel difference processing is performed to calculate the difference between the video signal of the pixel to be corrected and the video signal of a plurality of peripheral pixels having a distance (distance, distance) of 3 or more pixels from the pixel to be corrected. Since the contour correction signal is generated based on the difference addition signal obtained by adding the difference between the above and the contour correction signal is added to the video signal of the pixel to be corrected and down-converted, the degree of low frequency modulation is improved. At the same time, the degree of modulation in the high frequency range can be relatively reduced with respect to the degree of modulation in the low frequency range.

For example, when down-converting a 4K UHDTV to a 2K HDTV, the degree of modulation in the ultra-low frequency range of 1 MHz or less of the 2K jump scan HDTV is enhanced, and 1 MHz of the 2K jump scan HDTV is defined as 100%. It is possible to relatively reduce the 27.5 MHz modulation degree of a 2K HDTV.

Further, in the imaging device according to the embodiment of the present invention, the video signal of the pixel to be corrected is further added with the video signal of the pixel whose distance from the pixel to be corrected is within 2 pixels. Since the peripheral pixel difference processing for calculating the difference between the added signal and the video signal of a plurality of peripheral pixels having a distance of 3 pixels or more from the pixel to be corrected is performed, the ultra-low range It is possible to improve the degree of modulation and further reduce the degree of modulation in the high frequency range.

[Rough configuration of the imaging device according to the embodiment: FIG. 1]
The schematic configuration of the imaging apparatus (the present imaging apparatus) according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of the present imaging apparatus.
As shown in FIG. 1, the present imaging apparatus 102 includes a color separation optical system 105, a first green (G1, Green1) image sensor 103G1, a second green (G2, Green2) image sensor 103G2, and a red (R, Red) image sensor. It is a four-plate type image pickup device including the element 103R, the blue (B, Blue) image pickup element 103B, the video signal processing unit 104, and the CPU (Central Processing Unit) unit 106.
A lens 101 is attached to the image pickup apparatus.

Each part of the image pickup apparatus 102 will be described.
The color separation optical system 105 color-separates the incident light incident from the lens 101 into red (R), green (G1, G2), and blue (B).
The image pickup element 103 is a CMOS image pickup element, the image pickup element 103R photoelectrically converts red light, the image pickup elements 103G1 and 103G2 photoelectrically convert green light, and the image pickup element 103B photoelectrically converts blue light to light of each color. Generates a charge according to the strength of.
Here, in the image pickup device 103, pixels are arranged at a pixel pitch of 5 wavelengths or less with reference to the wavelength of green light (0.55 μm) which is the center wavelength of the image pickup light.
The color separation optical system 105 and the image sensor 103 correspond to the color separation unit described in the claims.

The video signal processing unit 104 performs various signal processing such as contour correction and down conversion.
The CPU unit 106 controls the entire image pickup apparatus, and in particular, the image pickup apparatus 102 controls the down converter unit, which will be described later, to realize appropriate contour correction.

Then, in the present image pickup device 102, the incident light is imaged by the lens 101, color-separated by the color-resolving optical system 105 for four plates, and the first green (G1) image sensor 103G1 and the second green (G2) image pickup are performed. Photoelectric conversion is performed by the element 103G2, the red (R) image sensor 103R, and the blue (B) image sensor 103B, various signal processing is performed by the video signal processing unit 104, and an HD-SDI (High Definition Serial Digital Interface) signal is output. do.
The video signal output from the imaging device 102 is not limited to HD-SDI, and may be compressed or encrypted.

The operation of this imaging device will be briefly described.
The light input from the lens 101 is separated into G1, G2, R, and B components in the color separation optical system 105, and is photoelectrically converted by the image sensor 103G1, 103G2, 103R, 103B, respectively, to become an electric signal.
Then, the signal of each color is subjected to gamma color correction and contour correction processing in the video signal processing unit 104, down-converted, and output to the outside as an HD-SDI video signal.
In the 4-plate type image pickup apparatus, the resolution is increased by performing the interpolation processing by shifting the oblique pixels using two green lights G1 and G2.

[Attachment position and resolution of image sensor: Fig. 2, Fig. 3]
Next, the bonding position and resolution of the image pickup elements in this image pickup apparatus will be described with reference to FIGS. 2 and 3.
FIG. 2 is a schematic explanatory view showing the degree of overlap of each pixel at the bonding position of the image pickup device in the image pickup device shown in FIG. 1, and FIG. 3 shows G1 and G2 of each pixel of the image pickup device of four plates. It is a schematic explanatory drawing which shows the difference between the oblique resolution and the vertical-horizontal resolution by oblique interpolation.

FIG. 2A shows an example of the bonding position of the pixels of the first green (G1) image sensor 103G1 and the second green (G2) image sensor 103G2 in the present image sensor. Further, FIG. 2B shows an example of the bonding position of the pixels corresponding to the Bayer arrangement.
At the pixel bonding positions of FIGS. 2 (a) and 2 (b), in general image processing, as shown in FIG. 3, the left-up image of (a) and the right-up image of (b) are G1G2. The vertical line image (c) and the horizontal line image (d) cannot be resolved by interpolation, and can be resolved by G1G2 interpolation.

[Structure of video signal processing unit 104: FIG. 4]
Next, the configuration of the video signal processing unit 104 of this imaging device will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the video signal processing unit 104.
As shown in FIG. 4, the video signal processing unit includes a chromatic aberration of magnification and a bonding error correction unit 107, an interpolation processing unit 108, a signal processing unit 110, a down converter unit 114, and a video signal output unit 180. , Is connected to the image sensor driving unit 190.

The Magnification Chromatic Aberration and Binding Error Correction Unit 107 corrects the Magnification Chromatic Aberration generated by the lens 101 with respect to the input G1 signal, G2 signal, R signal, and B signal, and the image sensor 103 and the color separation optical system 105. The bonding error is corrected and output to the interpolation processing unit 108.

The interpolation processing unit 108 includes a selection unit 115, an LPF (Low Pass Filter) unit 111, an LPF unit 112, an LPF unit 113, a subtraction unit 116, an addition unit 118, and an addition unit 119.
The selection unit 115 generates a G1 + G2 signal by alternately selecting and outputting a G1 signal and a G2 signal according to a clock signal from the image sensor driving unit 190.

Then, in the LPF unit 111 of the interpolation processing unit 108, the G1 + G2 signal from the selection unit 115 is delayed by the pixel delay unit 209 of the LPF unit 111, and the G1 + G2 signal not delayed by the addition unit 117 and the delayed G1 + G2 signal. Is added.
Further, the output of the pixel delay unit 209 is further delayed by the pixel delay unit 211, added to the output of the addition unit 209 by the addition unit 212, and the added signal is made uniform in the bit shift unit 210.
Then, the subtraction unit 116 of the interpolation processing unit 108 subtracts the output of the pixel delay unit 209 from the output of the bit shift unit 210 to generate a G difference signal.

The LPF units 112 and 113 include a delay unit that performs a delay corresponding to the delay time generated by the LPF unit 111 and a bit shift unit that aligns the sensitivities, and processes the R signal and the B signal, respectively.
The addition unit 118 adds a G difference signal to the signal obtained by processing the R signal by the LPF unit 112.
The addition unit 119 adds a G difference signal to the signal obtained by processing the G signal by the LPF unit 113.

The signal processing unit 110 performs signal processing such as gamma color correction for correcting the gradation of the image, and outputs a 4K video signal.
The down converter unit 114 is a characteristic portion of the image pickup apparatus, performs contour correction, and outputs a down-converted signal.

Specifically, the down converter unit 114 has a vertical contour correction unit that performs vertical contour correction, a horizontal contour correction unit that performs horizontal contour correction, and an oblique contour that performs diagonal contour correction for each of the G, R, and B signals. It is equipped with a correction unit, and after performing contour correction, which is a feature of this imaging device, down-converts 4K to 2K.
In particular, the down converter unit 114 of this imaging device includes a frame memory of a UHDTV camera, and generates a contour correction signal by difference processing of 68 pixels or more in the periphery.
Each contour correction unit will be described later.

The video signal output unit 180 converts and outputs a video signal according to the interface. Here, a 2K HD-SDI signal is output.
The image sensor driving unit 190 generates an image sensor pixel clock signal.

[First and second imaging devices]
The contour correction unit of this image pickup apparatus will be specifically described. The present imaging apparatus includes a first imaging apparatus having a different configuration of a contour correction unit and a second imaging apparatus.

[First imaging device]
The first imaging device does not calculate the difference between the video signal of the pixel close to the correction target pixel and the video signal of the correction target pixel in each contour correction unit so that the contour correction signal does not include a high frequency component. By doing so, the degree of modulation in the low frequency range is improved and the degree of modulation in the high frequency range is relatively reduced.

[Vertical contour correction unit of the first imaging device: FIG. 5]
Next, the configuration of the vertical contour correction unit (first vertical contour correction unit) of the down converter unit 114, which is a characteristic portion of the first imaging device, will be described with reference to FIG. FIG. 5 is a configuration diagram of the first vertical contour correction unit.
In the first imaging device, the first vertical contour correction unit 14 is provided corresponding to each of the G, R, and B signals (first vertical contour correction units 14G, 14R, 14B). , Since they all have the same configuration, they will be described here as a common first vertical contour correction unit 14.

The first vertical contour correction unit 14 corrects the vertical contour by comparing the video signals between the vertically arranged pixels in the lines (H) arranged in the vertical direction.
As shown in FIG. 5, the first vertical contour correction unit 14 includes a frame memory unit M0, a plurality of negative multipliers N0 to N31 and N37 to N68, a positive multiplier P4, and a plurality of adders 300. ~ 367, the image level determination device (image level determination unit) 28, the multipliers 29 and 32, the small amplitude large amplitude compression limiter (small amplitude large amplitude compression limiter) 31, and the correction signal addition unit 33. I have.

Here, the frame memory unit M0, the negative multipliers N0 to N31 and N37 to N68, the positive multiplier P4, and the plurality of adders 300 to 367 correspond to the difference addition unit described in the claim. The image level determination device 28 and the multipliers 29 and 32 correspond to the contour correction signal generation unit.

Each part of the first vertical contour correction part will be described.
The frame memory unit M0 holds the video signal and responds to the clock in order to obtain the difference between the video signal of the line to be corrected (let's say 34H) and the video signal of the lines 0H to 31H and 37H to 68H. Each line is output to the negative multipliers N0 to N31 and N37 to N68.

As a feature of the first imaging device, the difference between the video signal of the line to be corrected and the video signal of the line vertically separated from the correction target line by one pixel or two pixels is not calculated.
That is, the frame memory unit M0 of the first vertical contour correction unit 14 does not read the video data of 32H, 33H, 35H, and 36H.
That is, in the first imaging device, the difference from the correction target pixel is calculated using a plurality of lines (pixels) separated from the correction target line (pixel) by 3 pixels or more.

Further, the frame memory unit M0 outputs the correction target line (34H) to the positive multiplier P4, the image level determination device 28, and the contour correction signal addition unit 33.

The negative multipliers N0 to N31 multiply the video signal output from the frame memory unit M0 by a negative coefficient, and output the video signals to the adders 300 to 331, respectively.
The negative multipliers N37 to N68 multiply the video signal output from the frame memory unit M0 by a negative coefficient, and output the video signals to the adders 337 to 367, respectively.
The positive multiplier P4 multiplies the video signal of the correction target line (34H) output from the frame memory M0 by a positive coefficient.

The adders 300 to 367 add the outputs of the negative multipliers N0 to N31 and N37 to N68 and the positive multiplier P4, and output the difference addition signal from the adder 300. The adders 300 to 369 correspond to the difference addition unit in the claim.

Here, an instruction from the CPU 106 so that the difference addition signal output from the adder 300 becomes an appropriate signal based on the sum of the differences between the output from each negative multiplier and the output from the positive multiplier P4. Therefore, the coefficients of the positive multiplier P4 and / and the coefficients of the negative multipliers N0 to N31 and N37 to N68 are adjusted.
The negative multipliers N0 to N31 and N37 to N68 are set with a coefficient smaller than 1, and may be referred to as a divider.

That is, the difference addition signal output from the adder 300 is the peripheral 68 lines (centered on the correction target line) excluding the video signal of the correction target line (34H) and the 4 lines whose distance from the correction target line is within 2 pixels. It is the total difference from the video signal up to ± 34 lines).
In this way, the first imaging device does not perform high-frequency contour correction by generating a vertical contour correction signal that does not include the difference from the line within 2 pixels from the correction target line (not including 5H3H). I have to.

The image level determination device 28 determines the level of the image signal of the correction target line, and detects the dark portion by the threshold value determination.
The multiplier 29 variably adjusts the positive / negative and the amplification degree in order to attenuate the contour correction signal in the dark portion.

The CPU 106 controls the coefficients of the negative multipliers N0 to N31, N37 to N68 and the positive multiplier P4, and controls the positive / negative and the amplification degree of the amplification value multiplied by the multiplier 29 by the level control signal.

That is, in the CPU 106, the output from the adder 300 is the sum of the differences between the video signal of the correction target line (34H) and the video signals up to the peripheral 68 lines excluding the lines within 2 pixels from the correction target line. , The coefficient is controlled so that the level of the vertical contour correction signal is appropriate.

The small-amplitude large-amplitude compression limiter 31 compresses when the difference addition signal has a large amplitude, and limits the compression when the difference addition signal has a small amplitude.
The multiplier 32 multiplies the output from the small-amplitude, large-amplitude compression limiter 31 by the coefficients from the multiplier 29 to generate a vertical contour correction signal of appropriate polarity and level.
The correction signal addition unit 33 adds the vertical contour correction signal to the video signal (34H) of the correction target line output from the frame memory unit M0 to perform vertical contour correction, and outputs the corrected signal.

As described above, in the first imaging device, since the peripheral pixel difference processing with the video signal of the line within 2 pixels from the correction target line is not performed, the modulation degree of the ultra-low region can be enhanced and the modulation degree of the high region is relative. It lowers the target.
That is, in the first vertical contour correction unit 15, the high frequency contour correction by 5H3H is not performed, and the degree of modulation of the high frequency band is reduced.

[Operation of the first vertical contour correction unit: FIG. 5]
The operation of the first vertical contour correction unit 14 will be described with reference to FIG.
The pre-correction signal is input to the frame memory unit M0, accumulated at the clock timing, and output line by line to the negative multipliers N0 to N31, N37 to N68, and the positive multiplier P4.

Specifically, assuming that the correction target line output from the frame memory unit M0 is 34H, 0H, 1H, ... 31H are input to the negative multipliers N0 to N34, respectively, and 0H, 1H, ... 31H are input to the positive multiplier P4, respectively. H34 is input, and 37H, 38H, ... 68H are input to the negative multipliers N37 to N68, respectively.
32H, 33H, 35H, and 36H within 2 pixels from the correction target line are not output from the frame memory unit M0.

Then, the negative or positive coefficients are multiplied by the negative multipliers N0 to N31, N37 to N68, and the positive multiplier P4, and added by the adders 300 to 367, so that the video signal of the correction target line and other lines are added. The total difference from the video signal is calculated and output as a difference addition signal from the adder 300.

The difference addition signal is amplitude-adjusted by the small-amplitude large-amplitude compression limiter 31 and further amplified or attenuated by the multiplier 32 to an appropriate level according to the image level to generate a vertical contour correction signal. In the correction signal addition unit 33, the video signal of the correction target line and the vertical contour correction signal are added to perform contour correction in the vertical direction.
In this way, the operation of the first vertical contour correction unit 14 is performed.

In the present embodiment, a vertical contour correction signal is generated by performing peripheral pixel difference processing using a line having a distance (distance, distance) from the correction target line of 3 pixels or more and 34 pixels. However, it is also possible to use pixels of a line whose distance from the correction target line is larger than 34 pixels.
In either case, a vertical contour correction signal with an enhanced degree of modulation in the ultra-low region can be generated by not calculating the difference from the line whose distance from the correction target line is within 2 pixels.

[Structure of the first horizontal contour correction unit: FIG. 6]
Next, the configuration of the horizontal contour correction unit (first horizontal contour correction unit) of the first imaging device will be described with reference to FIG. FIG. 6 is a configuration diagram of the first horizontal contour correction unit.
The first horizontal contour correction unit corrects the horizontal contour by comparing the video signals between a plurality of pixels arranged in the horizontal direction on the same line.
The first horizontal contour correction unit 15 is also provided corresponding to each of the G, R, and B signals in the same manner as the first vertical contour correction unit described above, but here, the first horizontal contour correction unit 15 has a common configuration. This will be described as the horizontal contour correction unit 15 of 1.

As shown in FIG. 6, the first horizontal contour correction unit 15 includes a plurality of pixel delay units D0 to D67, a plurality of negative multipliers N100 to N131 and N137 to N168, and a plurality of positive multipliers P14. Adders 200 to 267, a video level determination device 48, multipliers 49 and 42, a small-amplitude large-amplitude compression limiter 41, and a correction signal adder 43 are provided.

That is, the first horizontal contour correction unit 15 is provided with pixel delay units D0 to D30, D313, D343, D36 to D67 instead of the frame memory unit M0 of the first vertical contour correction unit shown in FIG. Although the processing is performed on the pixels arranged in the horizontal direction, other basic configurations and operations are the same as those of the first vertical contour correction unit 14, so detailed description thereof will be omitted.

In the first horizontal contour correction unit 15, the pixel delay units D313 and D343 are three pixel delay units, so that the two pixels before and after the correction target pixel (34d) are not output, and the peripheral pixels. Not used for difference processing.
As a result, the high frequency contour correction by 5 pixels and 3 pixels is not performed, and the degree of modulation in the high frequency band is reduced.

That is, in the first horizontal contour correction unit 15, the sum of the differences between the video signal of the correction target pixel and the video signal of a plurality of pixels horizontally separated from the correction target pixel by 3 pixels or more in the horizontal direction is added from the adder 200. It is output as a difference signal, the amplitude correction of the addition difference signal is performed by the small amplitude large amplitude compression limiter 41, and the horizontal contour correction signal is adjusted by the multiplier 42 based on the determination result by the image level determination device 48. The generated, correction signal addition unit 43 adds the video signal of the correction target pixel (34d) and the horizontal contour correction signal, and performs contour correction in the horizontal direction.

Even in horizontal contour correction, peripheral pixel difference processing with pixels whose distance from the correction target pixel is within 2 pixels is not performed, so the degree of modulation in the ultra-low range can be increased and the degree of modulation in the high range is relatively high. It lowers it.

[Outline of diagonal contour correction: Fig. 7]
Next, the outline of the oblique contour correction performed by the oblique contour correction unit of the down converter unit 114 of the present imaging apparatus will be described with reference to FIG. 7. 7A and 7B are schematic explanatory views showing an outline of oblique contour correction, in which FIG. 7A shows an upper right oblique contour correction and FIG. 7B shows an upper left oblique contour correction.
The diagonal contour correction unit includes an upper right diagonal contour correction unit and an upper left diagonal contour correction unit, each of which performs upper right diagonal contour correction and upper left diagonal contour correction for the pixel to be corrected, and adds them to diagonal contour. Output as a corrected signal.

As shown in FIG. 7A, assuming that the pixel to be corrected is 4d of 4H, in the upper right oblique correction, 0d of 8H, 1d of 7H, 2d of 6H, 3d of 5H, 5d of 3H, 6d of 2H, 1H Peripheral pixel difference processing is performed using the 7d and 0H 8d pixels of the above, and a right diagonal upper contour correction signal is generated.

Further, as shown in FIG. 7B, in the upper left oblique correction, 0H 0d, 1H 1d, 2H 2d, 3H 3d, 5H 5d, 6H 6d, 7H 7d, 8H 8d pixels Peripheral pixel difference processing is performed using the above to generate an obliquely upper left contour correction signal.

[Structure of the first upper right diagonal contour correction unit: FIG. 8]
Next, the configuration of the upper right oblique contour correction unit (first upper right oblique contour correction unit) of the first imaging device will be described with reference to FIG. FIG. 8 is a configuration diagram of the first upper right oblique contour correction unit.
As shown in FIG. 8, the first upper right oblique contour correction unit 16a includes a frame memory M8, a plurality of negative multipliers N200 to N231 and N237 to N268, a positive multiplier P54, and a plurality of adders 400. ~ 467, an image level determining device 58, a multiplier 59, 52, a small amplitude large amplitude compression limiter 51, and a correction signal adding unit 53.

Then, in the first upper right oblique contour correction unit 16a, the frame memory unit M8 outputs the video signal of the correction target pixel (34d of 34H) to the positive multiplier P54, and as shown in FIG. 7A. The pixels arranged from the lower left to the upper right of the correction target pixel are output to the respective negative multipliers N200 to N231 and N237 to N268, and the total difference is calculated by the adders 400 to 467.

Here, as a feature of the first upper right diagonal contour correction unit 16a, similarly to the first vertical contour correction unit 14 and the first horizontal contour correction unit 15, the pixels within 2 pixels from the correction target pixel are peripheral pixels. Not used for difference processing.
That is, 32d of 36H, 33d of 35H, 35d of 33H, and 36d of 32H are not output from the frame memory unit M8.

That is, the first upper right diagonal contour correction unit 16a calculates the difference between the video signal of the pixel separated from the correction target pixel by 3 pixels or more and the video signal of the correction target pixel to generate the right diagonal upper contour correction signal. ..
As a result, the degree of modulation in the ultra-low region can be increased and the degree of modulation in the relatively high region can be relatively reduced.

[Structure of the first diagonally upper left contour correction unit: FIG. 9]
Next, the configuration of the upper left oblique contour correction unit (first upper left oblique contour correction unit) of the first imaging device will be described with reference to FIG. FIG. 9 is a configuration diagram of the first upper left oblique contour correction unit.
The configuration of the upper left diagonal contour correction unit 16b is the same as that of the upper right diagonal contour correction unit 16a shown in FIG. The difference is that the pixels are arranged.

Even in the first left diagonal contour correction unit 16b, the pixels within 2 pixels from the correction target pixel are not used for the peripheral pixel difference processing, and the image signal of the pixel separated from the correction target pixel by 3 pixels or more and the image of the correction target pixel are not used. The difference from the signal is calculated to generate the diagonally upper left contour correction signal.

[General configuration of contour correction unit of the first imaging device: FIG. 10]
Here, the general configuration of the contour correction unit of the first image pickup apparatus described so far will be described with reference to FIG. FIG. 10 is a general configuration diagram of a contour correction unit of the first image pickup apparatus.
As shown in FIG. 10, the contour correction unit 18 of the first imaging device represents all of the vertical contour correction unit, the horizontal contour correction unit, the right diagonal upper contour correction unit, and the left diagonal upper contour correction unit. The difference from the correction target pixel is calculated using a plurality of pixels separated from the correction target pixel by 3 pixels or more, and a contour correction signal is generated based on the difference.

In the configuration of FIG. 10, when the correction target pixel is 0d of 34H, the pixels read from the frame memory unit M8 are (34-34m) H of −34nd to (34-3m) H of -3nd, (34 + 3m). ) It can be described as 3nd of H to 34nd of 68H.

m and n are constants that take any of +1, 0, and -1, respectively. When m = 1, n = 0, the configuration of FIG. 10 becomes a vertical contour correction unit, and m = 0, n. When = 1, it becomes a horizontal contour correction unit.
Similarly, when m = -1, n = 1, it becomes the upper right diagonal contour correction part, and when m = 1, n = -1, it becomes the upper left diagonal contour correction part.

Here, in each contour correction unit in the first image pickup apparatus, the range of pixels for which peripheral pixel difference processing is performed is defined as pixels in which the distance (distance) from the correction target pixel is 3 pixels or more and 68 pixels. It can be less or more.
However, in the oblique contour correction unit, the range of peripheral pixel difference processing is set so that the distance from the correction target pixel is 68 pixels or more, for example, 136 pixels, and a negative multiplier and an adder are provided accordingly. Is desirable.

[Second imaging device]
In addition to the configuration of the first imaging device, the second imaging device adds a video signal of a pixel close to the correction target pixel to the video signal of the correction target pixel in each contour correction unit, so that a low frequency passing component is obtained. Is strengthened, the contour correction of the low region is performed strongly, and the relative modulation degree of the high region is further reduced.

[Structure of Second Vertical Contour Correction Unit: FIG. 11]
Next, the configuration of the vertical contour correction unit (second vertical contour correction unit) of the second imaging device will be described with reference to FIG. FIG. 11 is a configuration diagram of the second vertical contour correction unit.
As shown in FIG. 11, in the second vertical contour correction unit 24, in addition to the configuration of the first vertical contour correction unit 14 shown in FIG. 5, the distance from the correction target line is within 2 pixels. It has a configuration in which the video signal is added to the video signal of the correction target line.
The same reference numerals are given to the components equivalent to the first vertical contour correction unit.

Specifically, the second vertical contour correction unit 24 has the configuration of the first vertical contour correction unit 14, and further, positive multipliers P32, P33, P35, P36 and adders 332,333,335. It is equipped with 336.

Then, in the second vertical contour correction unit 24, the frame memory unit M0 reads out 32H, 33H, 35H, and 36H whose distance from the correction target line (34H) is within 2 pixels, and each is a positive multiplier. Output to P32, P33, P35, P36.
In each of the positive multipliers P32, P33, P35, and P36, an appropriate positive coefficient is multiplied by the control from the CPU unit 106, and the result is output to the adders 332, 333, 335, and 336, respectively.

That is, in the second vertical contour correction unit 24, the addition signal obtained by adding the video signal of the line within 2 pixels from the correction target line to the video signal of the correction target line at an appropriate level and the distance from the correction target line are calculated. The vertical contour correction signal is generated by calculating the difference between the video signals of a plurality of lines having three or more pixels.

As a result, in the second vertical contour correction unit 24, 5H3H can be added to generate a low frequency passing component, the low frequency contour can be further corrected (emphasized), and the high frequency modulation degree can be relatively corrected. It can be reduced to.

[Structure of Second Horizontal Contour Correction Unit: FIG. 12]
Next, the configuration of the horizontal contour correction unit (second horizontal contour correction unit) of the second imaging device will be described with reference to FIG. FIG. 12 is a configuration diagram of the second horizontal contour correction unit.
As shown in FIG. 12, the second horizontal contour correction unit 25 includes positive multipliers P132, P133, P135, P136 and adders 233,233, in addition to the configuration of the first horizontal contour correction unit 15. It has 235 and 236.
Further, instead of the pixel delay units D313 and D343, which are the three pixel delay units provided in the first horizontal contour correction unit 15, pixel delay units D31 to D36 that perform one pixel delay are provided.

Then, in the second horizontal contour correction unit 25, the pixel delay units D31, D32, D35, and D36 respectively set 32d, 33d, 35d, and 36d in which the distance from the correction target pixel (34d) is within 2 pixels. It is output to the positive multipliers P132, P133, P135, P136, and after level adjustment, it is output to the adder 232, 233, 235, 236.

Then, the second horizontal contour correction unit 25 adds the video signal of the pixel whose distance from the correction target pixel is within 2 pixels to the video signal of the correction target pixel at an appropriate level, and adds the addition signal and the video signal. A horizontal contour correction signal is generated by calculating the difference from the video signals of a plurality of pixels having a distance of 3 or more pixels from the correction target pixel.
As a result, even in the horizontal contour correction, the degree of modulation in the low region is further enhanced, and the degree of modulation in the high region is relatively lowered.

[Structure of the second upper right diagonal contour correction unit: FIG. 13]
The configuration of the second upper right diagonal contour correction unit will be described with reference to FIG. FIG. 13 is a configuration diagram of a second upper right oblique contour correction unit.
As shown in FIG. 13, the second upper right oblique contour correction unit 26a includes the positive multipliers P232, P233, P235, and P236 in addition to the configuration of the first upper right oblique contour correction unit 16a shown in FIG. , The adder 432, 433, 435, 436 and.

Then, similarly to the second vertical contour correction unit 24 and the second horizontal contour correction unit 25, the video signal of the correction target pixel (34d of 34H) is a pixel whose distance from the correction target pixel is within 2 pixels. The vertical contour correction signal is generated by calculating the difference between the addition signal obtained by adding the video signal at an appropriate level and the video signal of a plurality of pixels having a distance of 3 pixels or more from the correction target pixel. ..

[Structure of the second upper left diagonal contour correction unit: FIG. 14]
The configuration of the second upper left oblique contour correction unit will be described with reference to FIG. FIG. 14 is a configuration diagram of a second upper left oblique contour correction unit.
As shown in FIG. 14, the second upper right oblique contour correction unit 26b includes the positive multipliers P332, P333, P335, and P336 in addition to the configuration of the first upper left oblique contour correction unit 26b shown in FIG. , The adder 532, 533, 535, 536.

Then, similarly to the second upper right oblique contour correction unit 26a, the video signal of the pixel whose distance from the correction target pixel (34d of 34H) is within 2 pixels is added to the video signal of the correction target pixel to obtain the addition signal. The vertical contour correction signal is generated by calculating the difference from the video signals of a plurality of pixels having a distance of 3 pixels or more from the correction target pixel.

[Signals after contour correction of the first and second imaging devices: FIG. 15]
Next, the signal after contour correction (signal after contour correction) in the first and second imaging devices will be described with reference to FIG.
15A and 15B are explanatory views of the contour-corrected signal in the first and second imaging devices, where FIG. 15A is a signal before correction, FIG. 15B is a contour correction signal based on a 7H component / 7 pixel component, and (c). ) Is a contour correction signal based on the 9H component / 9 pixel component, (d) is a contour correction signal based on the 11H component / 11 pixel component, (e) is a contour correction signal based on the 13H component / 13 pixel component, and (f) is a contour correction signal based on the 13H component / 13 pixel component. , The contour-corrected signal of the first imaging device, (g) is the contour-corrected signal of the second imaging device, (h) is the contour correction signal by the 5H component / 5 pixel component, and (i) is the 3H component. The contour correction signal by the / 3 pixel component is shown.

The contour correction signal based on the 3H component / 3 pixel component in (i) is a contour correction signal based on the difference between the video signal of the line / pixel separated by one pixel from the correction target pixel and the correction target pixel. It is not generated by the first and second imaging devices.
Similarly, the contour correction signal based on the 5H component / 5 pixel component in (h) is a contour correction signal based on the difference between the video signal of the line / pixel separated by 2 pixels from the correction target pixel and the correction target pixel. It is not generated by the first and second imaging devices.

The contour-corrected signal of the first imaging device shown in (f) is a contour corrected by a contour correction signal consisting of 68H67H ... 13H11H9H7H component / 68 pixel 67 pixel ... 13 pixel 11 pixel 9 pixel 7 pixel component. This is the corrected signal.
The contour correction signal does not include the 5H3H component / 5 pixel 3 pixel component, and emphasizes the ultra-low frequency contour.

Then, the down converter unit 114 of the first imaging device outputs every other generated signal (f) and down-converts it. The 27.5 MHz modulation degree when 10 kHz is used as a reference is set to 35%, which is constant without being increased as compared with that before the correction.

Further, the contour-corrected signal of the second image pickup apparatus shown in (g) is obtained by adding the 5H3H component / 5 pixel 3 pixel component to the correction target pixel component to perform contour correction. That is, the contour-corrected signal including the 5H3H component / 5-pixel 3-pixel component LPF output and corrected by the contour-correcting signal of 68H67H ... 13H11H9H7H component / 68-pixel 67-pixel ... 13-pixel 11-pixel 9-pixel 7-pixel component. Is.
By correcting the low frequency passage of the 5H3H component / 5 pixel 3 pixel component, the outline of the ultra-low frequency band can be further emphasized.

The down converter section 114 of the second imaging device outputs the generated (g) signal every other signal and down-converts it to reduce the modulation factor of 27.5 MHz based on 10 kHz to 15%. There is.

[Modulation degree in the first and second imaging devices: FIG. 16]
Next, the degree of modulation in the first and second imaging devices will be described with reference to FIG. 16A and 16B are explanatory views showing the degree of modulation in the first and second image pickup devices, where FIG. 16A is a first image pickup device and FIG. 16B is a pre-correction signal and a post-correction signal of the second image pickup device. Indicates the degree of modulation of.
As shown in FIG. 16A, in the first imaging device, the contour correction by the 3H5H component / 3 pixel 5 pixel component is not performed, and the 1 MHz MTF based on 10 kHz is corrected from 65% before the correction. Later, it improves to 70%, and the 1 MHz standard 27.5 MHz MTF decreases from 35/65 = 54% to 35/70 = 50%.
That is, in the first imaging device, the degree of modulation in the low region can be improved and the relative degree of modulation in the high region can be sufficiently reduced.

FIG. 16B shows a case where the 3H5H component / 3 pixel 5 pixel component LPF output is added to the video signal of the pixel to be corrected, and the 1 MHz MTF based on 10 kHz is changed from 65% before correction to 70% after correction. It improves and the 1MHz standard 27.5MHz MTF decreases from 35/65 = 54% to 15/70 = 21%.
In the second imaging device, the modulation degree in the low frequency range can be improved and the relative MTF in the high frequency range can be significantly reduced as in the case of the first imaging device.

[Effect of Embodiment]
According to the first and second image pickup devices according to the embodiment of the present invention, a CMOS image pickup element having a pixel pitch of 5 or less of the center wavelength of the image pickup light is used, and two green image pickup elements perform oblique pixel shift. In the four-plate image sensor, the down converter unit 114 uses an image signal of a pixel to be corrected for contour correction and an image of a plurality of peripheral pixels in which the distance (distance, distance) from the pixel to be corrected is 3 pixels or more. Peripheral pixel difference processing for calculating the difference from the signal is performed, a contour correction signal is generated based on the difference addition signal obtained by adding the plurality of differences, the contour correction signal is added to the video signal of the pixel to be corrected, and the image is down. Since the conversion is performed, the visually important low-frequency contour and the degree of modulation can be improved, and the high-frequency modulation degree can be relatively reduced by not performing the high-frequency contour correction. There is.

In particular, according to the first and second imaging devices, when down-converting a 4K UHDTV to a 2K HDTV, the ultra-low range of the HDTV of 2K jump scanning of 1 MHz or less is enhanced to enhance the ultra-low frequency of 2K jump scanning. There is an effect that the 27.5 MHz modulation degree of 2K HDTV, which is defined as 100% of 1 MHz of HDTV, can be reduced to 50%.

Further, according to the second imaging device, the low-frequency passing signal is obtained by adding the video signal of the pixel to be corrected to the image signal of the pixel to be corrected and the distance from the pixel to be corrected to be within 2 pixels. Since the peripheral pixel difference processing is performed to calculate the difference between the generated low-frequency passing signal and the video signal of a plurality of peripheral pixels having a distance of 3 pixels or more from the pixel to be corrected, it is ultra-low. It has the effect of enhancing the contour correction signal of the region, improving the modulation degree of the ultra-low region, and significantly reducing the modulation degree of the high region.

Further, according to the first and second imaging devices, in the down converter, in addition to the vertical contour correction and the horizontal contour correction, the upper right diagonal contour correction and the upper left diagonal contour correction are performed. Modulation Hall It is possible to strongly correct the low right diagonal and left diagonal contours, which has the effect of improving visually important diagonal contours.

Further, according to the first and second image pickup devices, although the low frequency MTF is high, the low frequency MTF is electronically corrected without using an expensive and large super 35 mm size large image sensor. Therefore, there is an effect that the degree of freedom of 8K4K2K video production can be increased at low cost.

According to the first and second imaging devices, the range of pixels for which peripheral pixel difference processing is performed in each contour correction unit of the down converter 114 is such that the distance (distance) from the correction target pixel is 3 to 68 pixels. Since the pixels are used, there is an effect that the degree of modulation in the low frequency range can be improved and the degree of modulation in the high frequency range can be reduced without increasing the circuit configuration.

The range in which the peripheral pixel difference processing is performed is not limited to this, and the distance from the correction target pixel may exceed 68 pixels, and may include a farther pixel such as 136 pixels, and the degree of modulation in the low frequency range may be adjusted. It has the effect of further improving and reducing the degree of modulation in the high frequency range.

In addition, the 2 / 3-inch 4K image sensor for news reports and the 1.25-inch 8K image sensor for relay have the same pixel spacing of 2.5 μm and a pixel pitch of about 4.5 times the green wavelength, which is super. The aberration at the telephoto is large, the aperture is dark, and the MTF is low, but according to the first and second image sensors, those characteristics can be tolerated and the MTF at low frequencies can be improved. , There is an effect that the price of the image sensor can be reduced.

INDUSTRIAL APPLICABILITY In a 4-plate type image pickup device using a CMOS image sensor having a small pixel pitch, the present invention can improve the degree of modulation in the low range and relatively reduce the degree of modulation in the high range during down-conversion. Suitable for equipment.

14, 24 ... Vertical contour correction unit, 15, 25 ... Horizontal contour correction unit, 16a, 26a ... Upper right diagonal contour correction unit, 16b, 26b ... Upper left diagonal contour correction unit, 18 ... Contour correction unit, 28, 48, 58, 68 ... Video level judge, 29, 32, 42, 49, 52, 59, 62, 69 ... Multiplier, 31, 41, 51, 61 ... Small amplitude Large amplitude compression limiter, 33, 43, 63 ... Correction signal Adder unit, 101 ... Lens, 102 ... Imaging device, 103, 103G1, 103G2, 103R, 103B ... Imaging element, 104 ... Video signal processing unit, 105 ... Color separation optical system, 106 ... CPU unit, 107 ... Magnification chromatic aberration Lamination error correction unit, 108 ... interpolation processing unit, 110 ... signal processing unit, 114 ... down converter unit, 180 ... video signal output unit, 190 ... image pickup element drive unit, 111, 112, 113 ... LPF unit, 116 ... subtraction Instrument, 117,118,119,212,200-267,300-367, 400-467,500-567 ... Adder, 209,211 ... Pixel delay part, 210 ... Bit shift part, M0, M8 ... Frame memory part , N0 to N68, N100 to N168, N200 to N268, N300 to N368 ... Negative multipliers, P4, P14, P54, P64, P32, P33, P35, P36, P132, P133, P135, P136, P232, P233 P235, P236, P332, P333, P335, P336 ... Positive multiplier, D0 to D67 ... Pixel delay, 91 ... Microlens, 92 ... Color filter, 93 ... Photodiond, 94 ... Metal wiring layer

Claims (4)

An image pickup device that uses two green CMOS image sensors, red, blue, and two green CMOS image sensors whose pixel pitch is 5 times or less the center wavelength of the image pickup light, and diagonally shifts the pixels with the two green CMOS image sensors.
A color separation optical system for decomposing the input light for each color, the red output image signal by photoelectric conversion for each color light decomposed by the color separation optical system, a blue and two green CMOS image sensor And the color separation part with
An interpolation processing unit that performs interpolation processing based on the signal from the color separation unit, and an interpolation processing unit.
It has a down converter unit that down-converts and outputs the video signal from the interpolation processing unit after performing contour correction.
The down converter unit calculates the difference between the video signal of the pixel to be corrected for contour correction and the video signal of a plurality of pixels having a distance of 3 or more pixels from the pixel to be corrected, and the plurality of An imaging device including a contour correction unit that generates a contour correction signal based on a difference addition signal obtained by adding differences and adds the contour correction signal to the video signal of the pixel to be corrected to perform contour correction. .. The contour correction unit adds the video signal of the pixel whose distance from the pixel to be corrected is within 2 pixels to the video signal of the pixel to be corrected, and the added signal and the pixel to be corrected The imaging device according to claim 1, wherein the contour correction is performed by calculating the difference between the video signals of a plurality of pixels having an interval of 3 pixels or more. The contour correction unit includes a vertical contour correction unit that corrects the vertical contour, a horizontal contour correction unit that corrects the horizontal contour, and an oblique contour correction unit that corrects the upper right diagonal contour and the upper left diagonal contour. The imaging apparatus according to claim 1 or 2, wherein the image pickup apparatus is provided with. The imaging device according to any one of claims 1 to 3, wherein the contour correction unit uses pixels having a distance of up to 68 pixels from the correction target pixel in generating the difference addition signal.

Images