JP6176775B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus, and more particularly to reduction of fixed pseudo signals.

  For example, in an HDTV (High Definition TeleVision) image pickup device, a vertical streak-like fixed pseudo signal that repeats horizontally, which is peculiar to a video signal, is generated even when there is no light to be imaged due to the influence of a drive circuit of an image pickup tube. In particular, horizontal shading (such as ringing and non-constant vertical streaks due to the temperature characteristics of bypass capacitors, inductors, and FPGAs) changes slowly at low temperature startup. In order to extract a high-quality video signal, it is necessary to remove this vertical streak-like fixed pseudo signal and horizontal shading. A conventional method for solving this problem will be described.

One of the conventional methods is that in an HDTV image pickup apparatus using an image pickup tube, images in a horizontal scanning line period (line) in a vertical blanking period are added and averaged in the vertical direction, and one line of image data is stored in memory. The fixed pattern noise is removed by subtracting from the video of the effective horizontal scanning line period (line) (see Patent Document 1). In another method, the video in the horizontal scanning line period of the vertical effective period is added and averaged in the vertical direction in the process of auto black processing, one line of image data is stored, and the horizontal scanning line period of the vertical effective period ( The fixed pattern noise is removed by subtracting from the video of the line (see Patent Document 2).
However, CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor) solid-state imaging devices for HDTV have four vertical-optical black (V-OB) lines and are effective V- with less noise. There are few OB lines. Video CMOS solid-state imaging devices with more scanning lines such as UHDTV also have as few as one effective V-OB line with less noise. Therefore, even if the video of the V-OB line is averaged in the vertical direction and subtracted from the video in the horizontal scanning line period (line) of the vertical effective period, the vertical streak-like fixed pseudo signal is affected by noise and white scratches. Removal will be incomplete.

Japanese Patent Laying-Open No. 2005-094626 JP 2006-287392 A

  In order to solve this drawback, an object of the present invention is to realize removal of a vertical streak-like fixed pseudo signal in an imaging apparatus using a solid-state imaging device having a V-OB.

  In order to solve the above-mentioned object, in an imaging apparatus using a solid-state imaging device having vertical optical black (Vertical-Optical Black: V-OB), V (in order to eliminate other components as white scratches and noise) V -Subtract fixed pattern noise (vertical streak component) with a power-of-two pixel period from the OB signal (and remove the H-shading component in pixel units. If it is 0 dB, the left half is 1% or less and 5% or more and the right half is 0%. 1% or more, and when starting at +36 dB, the left end is 63% or less and 315% or more, the right half is 0% or less and 63% or more, the first end is wide and the second half is narrow, and after startup the horizontal sawtooth (H-Saw) The width of horizontal shading (H-shading) is calculated by adding the component of the vertical power of 2 to each component of the horizontal jumping (H-Top-Frame) and horizontal ringing (H-ringing) components. Amplification and horizontal shading (H-shading) The pixel signal outside the range of the first variable threshold (white scratch or black scratch) is interpolated with the average of the left and right pixels (if there is no continuous scratch) (if there is a continuous scratch) (the weighted average value of the left and right pixels) Alternatively, the imaging device is characterized in that it interpolates with a calculated value (of a cubic curve value) and adds a component of a power cycle vertical stripe of 2 and subtracts it from an effective pixel signal as an H-shading correction signal (FIG. 4A). And the common superordinate concept of FIG. 4B).

In the imaging apparatus described above, the first variable threshold value is set in accordance with the amplification degree and horizontal shading (H-shading) (the first end is wide at the start and the second half is narrow, and the upper and lower ranges of the H-shading waveform after the start). After interpolating a pixel signal (dark current abnormality or noise) that is significantly different from the second variable threshold of a fraction of the range with the weighted average value of the left and right four pixels, the weighted average value of the left and right four pixels and the first The signal obtained by interpolating the pixel signal that is significantly different from the second variable threshold value, which is a fraction of the variable threshold range, with the weighted average value is averaged by the power cycle of 2, and the component of the power cycle vertical stripe of 2 is added. Thus, the image pickup apparatus subtracts the effective pixel signal as an H-shading correction signal (FIG. 4A).
In the imaging apparatus, after interpolating a pixel signal outside the range of the first variable threshold according to the amplification factor and the H-shading component with a cubic curve value of four left and right pixels, the V-OB signal is converted into a horizontal signal. It is decomposed into each component of sawtooth (H-Saw) component, horizontal image rising edge (H-Top-Frame) component and horizontal ringing (H-ringing) component, and the composition of each component is converted to horizontal shading (H- It is an imaging apparatus characterized by using a correction signal (shading) (FIG. 4B).

  Further, in the above image pickup apparatus, V-OB white scratches are stored by shading immediately before power-off at the time of dark part adjustment or power-off at the time of light-off. White scratches are the weighted average value or cubic curve value of 4 pixels on the left and right. ) An imaging apparatus characterized by interpolating with a calculated value. (Fig. 4B)

  According to the present invention, in an imaging device using a solid-state imaging device having a V-OB, a fixed pattern noise (longitudinal streak) with a horizontal period (whether it changes gently at low temperature startup or has many white scratches at high temperature). It is possible to stably remove horizontal shading without generating any component.

The block diagram which shows one Example of the television camera of this invention. FIG. 3 is a schematic diagram illustrating a pixel configuration of an image sensor. The block diagram which shows the structure of the real-time horizontal shading correction | amendment part of one Example of this invention. The block diagram which shows the circuit structure of the real-time horizontal shading component detection part of one Example of this invention. (Weighted average interpolation of left and right four pixels with a first interpolation variable threshold value for removing white scratches and black scratches after vertical stripe component removal, and a second interpolation variable threshold value for dark current abnormality and noise removal, (Noise average part of power cycle (about 8 pixels) and horizontal shading component average part.) The block diagram which shows the circuit structure of the real-time horizontal shading component detection part of one Example of this invention. (After removal of white scratches such as power-off after removing vertical streak components, an interpolation unit outside the range of the second variable threshold from the cubic curve value of the left and right 4 pixels, and a noise averaging unit of the ringing period or more (about 32 pixels) , Detection and synthesis of H-Saw and H-Top-Frame components) The schematic diagram of the interpolation variable threshold value of the real-time horizontal shading component detection of one Example of this invention. ((A) Schematic diagram of V-OB value (b1) V-OB waveform from which vertical streak component has been removed, and first interpolation variable threshold value with a wide initial start point (for white scratches and black scratches) and a narrow second half Schematic diagram (b2) Schematic diagram of the first interpolation variable threshold values above and below the V-OB waveform with the vertical stripe component removed and the normal H-Shading waveform (for removing white scratches and black scratches) (c) Vertical stripe component removal (D) Schematic diagram of second interpolation variable threshold (for dark current abnormality and noise removal) (d) Schematic diagram of waveform after LPF (e) Schematic diagram of H-Shading waveform with added vertical streak component ) The schematic diagram which shows the component detection and a synthesis | combination of the real-time horizontal shading component detection part of one Example of this invention. ((A) Schematic diagram of V-OB value (b) Schematic diagram of V-OB waveform with vertical streak component removed (c) V-OB waveform with vertical streak component and white and black scratches removed (d) H-Saw component (E) Schematic diagram of H-Top-Frame component (f) Schematic diagram of H-Ringing component) 4 is a timing chart illustrating an example of the present invention. The block diagram which shows the conventional television camera.

  FIG. 1 is a block diagram showing an embodiment of a television camera of the present invention, FIG. 2 is a schematic diagram showing a pixel configuration of an image sensor, and an embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of a real-time horizontal shading correction unit, and a block diagram showing a circuit configuration of a real-time horizontal shading component detection unit according to an embodiment of the present invention (removal of white scratches and black scratches after removal of vertical stripe components) A first interpolation variable threshold value for use, a weighted average value interpolation of left and right four pixels at a second interpolation variable threshold value for dark current abnormality and noise removal, and a noise averaging unit having a power cycle of 2 (about 8 pixels) 4A of the horizontal shading component average unit) and a block diagram showing the circuit configuration of the real-time horizontal shading component detection unit of the embodiment of the present invention (after removing the white scratches such as the power off after removing the vertical streak component, left Detection and synthesis of the second variable threshold out-of-range interpolation from the cubic curve value of the right 4 pixels, the noise averaging part above the ringing period (about 32 pixels), H-Saw component and H-Top-Frame component) FIG. 4B, FIG. 5A of a schematic diagram of an interpolation variable threshold value for real-time horizontal shading component detection of one embodiment of the present invention, and component detection and synthesis of the real-time horizontal shading component detection unit of one embodiment of the present invention. 5B of the schematic diagram shown and FIG. 6 of the timing chart explaining the Example of this invention are demonstrated.

The difference between FIG. 1 and FIG. 7 of the block diagram showing the conventional television camera is that, in order to solve the above object, 8A of the video signal processing unit with a real-time shading correction function, In order to eliminate as scratches and noise, subtract the component of the power-cycle vertical stripe of 2 from the V-OB signal as small as about 1 scan line (and remove the H-shading component in pixel units), and if it is 0 dB, the left end 1 % And 5% or more, right half 0% or less and 1% or more, and + 36dB, left edge 63% or less and 315% and right half 0% or less and 63% or more) According to each amplification factor and H-shading component When starting up, the first end is wide and the second half is narrow. When normal, pixel signals (white scratches and black scratches) outside the first variable threshold range above and below the H-Shading waveform (if there are no continuous scratches) Interpolated on average (if there are continuous flaws), left and right 4 pixel weights After interpolating with the average value, pixel signals (dark current abnormality and noise) that are significantly different from the weighted average value of each of the left and right four pixels (each H-shading component) and more than a fraction of the first variable threshold range Add a component of the vertical power of 2 to the interpolated (weighted moving average) signal with a cubic curve value to make an H-shading correction signal, or a V-OB signal as small as about 1 scan line to a power of 2 H-shading of periodic longitudinal stripes, H-SAW, H-Top-Frame, H-Ringing, decomposed into each component, and the function of combining each component of H-shading as an H-shading correction signal, that is, shading in real time The function to correct is included.
In the above image pickup apparatus, V-OB white scratches with as little as about one scanning line are stored with light shielding immediately before dark power adjustment with light shielding or immediately before power turn-off at the time of power turn-off. You may interpolate with the calculated value (of the cubic curve value). The power supply turn-off may be set as a soft control, and the power supply may be turned off after storing the white scratch of the V-OB by shielding light immediately before the power supply turn-off at the time of power supply turn-off.

In FIG. 1, 1 is a television camera, 2 is a lens, 3 is a prism, 4R, 4G and 4B are CCD, 5R, 5G and 5B are CDS, 6R, 6G and 6B are VGA, 7R, 7G and 7B are A / A. A D conversion unit, 8A is a video signal processing unit with a vertical stripe correction function, 9 is a video signal output unit, 10 is a TG, and 11 is a CPU.
In FIG. 1, incident light from a subject is imaged by a lens unit 2, and the formed incident light is decomposed into red light, green light, and blue light by a prism unit 3 of a television camera 1. The (Charge Coupled Device) part 4R is incident, the green light is incident on the CCD part 4G, and the blue light is incident on the CCD part 4B.

The red light incident on the CCD unit 4R is photoelectrically converted by the CCD unit 4R to become a red signal. The red signal is denoised by a CDS (correlated double sampling) unit 5R, amplified to a predetermined level by a VGA (variable gain amplifier) unit 6R, and converted to a digital signal by an A / D conversion unit (Analog Digital converter) 7R. As a result, an R signal is obtained. The CDS, VGA, and A / D converter are often integrated into an AFE (Analog Front End).
Similarly, the green light incident on the CCD unit 4G is photoelectrically converted by the CCD unit 4G to become a green signal. From the green signal, noise or the like is removed by the CDS unit 5G integrated with the AFE, amplified to a predetermined level by the VGA unit 6G, converted into a digital signal by the A / D conversion unit 7G, and converted into a G signal.
Similarly, the blue light incident on the CCD unit 4B is photoelectrically converted by the CCD unit 4B to become a blue signal. The blue signal is denoised by the CDS unit 5B integrated with the AFE, amplified to a predetermined level by the VGA unit 6B, converted into a digital signal by the A / D conversion unit 7B, and becomes a B signal.

The R signal, the G signal, and the B signal are subjected to various video signal processing such as color correction, contour correction, gamma correction, and knee correction in the video signal processing unit 8A with a real-time shading correction function, and the video output unit 9 performs video signal processing. Is output.
A CPU (Central Processing Unit) 11 controls each part of the television camera 1. A TG (Timing Generator) 10 is a timing signal generator for driving the image sensor 4 and the CDS circuit 5.

The timing signal generated by the TG 10 may jump into 4R, 4G, or 4B of the image sensor, or 5R, 5G, or 5B of the CDS, thereby degrading the image quality.
A jump signal by TG 10 (hereinafter referred to as TG noise) is a fractional cycle of a power of 2 (such as two, four, or eight) of the system clock. The TG noise is generally a signal having a period of 1/8 or 1/4, and this appears in the video as a fixed pattern noise having a vertical stripe shape. Also, in TG10, when asynchronous frequency division is performed with respect to the horizontal sync signal of the video signal, the phase of the TG noise changes when the power is turned on or when the clock signal is turned on again when the mode of the device is switched. To do.

  Therefore, in order to extract this pattern, horizontal addition averaging is performed for each pixel of powers of 2 such as 2 or 4 or 8. This extracts a fixed pattern that is repeated every 2 power pixels, such as 2 or 4 or 8, and subtracts it from the original video to correct vertical stripes, thereby reducing image quality degradation due to fixed pattern noise. To prevent.

  As shown in FIG. 2, the pixel configuration of the image sensor 4 is composed of effective video pixels and vertical and horizontal BL (blanking) pixels. The BL pixel is composed of an OB (Optical Black) and a non-pixel portion where no pixel exists.

  In order to obtain a correction effect even during normal imaging, OB (V-OB) of a vertical BL pixel having a fixed pattern is used. There are about four V-OB lines, and there are about two V-OBs that can be used for fixed pattern noise extraction with little noise, and a fixed pattern is extracted from these two lines of V-OBs.

An embodiment of the present invention will be described below with reference to FIGS. 3, 4A, 4B, 5A, 5B, and 6. FIG.
FIG. 3 is a block diagram of a real-time horizontal shading correction unit. FIG. 4A is a block diagram illustrating a circuit configuration of a real-time horizontal shading component detection unit according to an embodiment of the present invention. (Weighted average interpolation of left and right four pixels with a first interpolation variable threshold for removing white scratches and black scratches after removal of vertical streak components, and a second interpolation variable threshold for dark current abnormality and noise removal). FIG. 4B is a block diagram illustrating a circuit configuration of a real-time horizontal shading component detection unit according to an embodiment of the present invention. (Detection and synthesis of H-Saw component, H-Top-Frame component, and H-Ringing component after removal of memory white scratches such as power-off after vertical stripe component removal). FIG. 5A is a schematic diagram of an interpolation variable threshold value for real-time horizontal shading component detection according to an embodiment of the present invention. FIG. 5B is a schematic diagram illustrating component detection and synthesis of the real-time horizontal shading component detection unit according to an embodiment of the present invention. FIG. 6 is a timing chart for explaining an embodiment of the present invention.
FIGS. 3, 4A, 4B, 5A, and 5B show only one channel, but in actuality, the same circuit is composed of three RGB channels.
Here, an example of removing periodic fixed pattern noise of 8 pixels due to TG noise will be described with reference to FIGS.

FIG. 3 is a block diagram of the fixed pattern correction unit. The fixed pattern correction unit is included in 8A of the video signal processing unit with a real-time shading correction function in FIG. The fixed pattern correction unit includes adders 12a to 12c, switches 13a to 13b, flip-flops 14a to 14h, an average value calculation unit (bit shift division unit) 15, an offset removal unit 16, and subtractors 17a to 17b.
The fixed pattern correction unit adds the signals of the two lines of the vertical OB part of the input signal every 8 pixels, calculates the average value for each 8 pixels, removes the offset, and subtracts it from the input signal. The fixed pattern noise with a period of 8 pixels superimposed on the signal is removed.
Details of the operation will be described below.

  FIG. 6 shows a timing chart. add_enable is a signal that is controlled to High when the addition process is performed, and controls the switch 13a in FIG. add_enable is controlled to a period High of 1920 pixels corresponding to the effective image portion in the effective image period in the vertical OB portion in the vertical blanking period. At this time, the switch 13 is controlled to the a side by add_enable, and the adder 12 adds the input signal and the result of adding the previous 8 pixels of data stored in the flip-flops 14a to 14h to the flip-flop 14a again. By repeating this every 8 pixels, a pattern of 8 pixel periods is extracted to the flip-flops 14a to 14h.

  Add_enable is controlled to Low except during the previous addition period. At this time, the switch 13a is controlled to the b side by add_enable, and the data stored in the flip-flops 14a to 14h goes around the flip-flop every 8 pixels. Thereafter, the average noise is averaged by the average value calculator 15 to reduce the random noise, the offset is removed by the offset remover 16, and then subtracted from the input signal to remove the fixed pattern of the 8-pixel cycle. Get. “reset” becomes “High” one line before the above addition processing, and resets the flip-flops 14a to 14h.

In this embodiment, eight flip-flops are used, but by using eight flip-flops, it is possible to extract and remove a pattern with a 4-pixel cycle or a fixed pattern noise (vertical stripe component) with a 2-pixel cycle. It is.
As another example, when removing periodic fixed pattern noise of four pixels, a configuration using four flip-flops can be used to form a pattern of four pixel periods or a fixed pattern noise (vertical length of two pixels). Muscle component) can be extracted and removed.

  Further, if the number of flip-flops in FIG. 3 is increased and a power of 2 such as 16, 32, or 64 is used, the system clock has a 16-minute period, a 32-minute period, a 64-minute period, or the like. Vertical streak-like fixed pattern noise having a period of a power of 2, that is, a power of 2 such as 16, 32, or 64, can be extracted.

  Hereinafter, with respect to an embodiment of the present invention, for removal of white scratches and black scratches after removal of fixed pattern noise (vertical streak component) having a power cycle of 2 in the real-time horizontal shading component detection unit of the embodiment of the present invention. FIG. 4A is a block diagram showing a circuit configuration (between the weighted average values of the left and right four pixels at the first interpolation variable threshold, dark current abnormality, and second interpolation variable threshold for noise removal), and one embodiment of the present invention A difference from the first embodiment will be described with reference to FIG. 5A of a schematic diagram of an interpolation variable threshold value for real-time horizontal shading component detection.

4A is a block diagram illustrating a circuit configuration of a real-time horizontal shading component detection unit according to an embodiment of the present invention. In FIG. 4A, 18 is a horizontal shading component detection unit, and 19 is a fixed pattern noise (vertical streak) having a power-of-two pixel period. Component) A first interpolation variable threshold value for removing white scratches and black scratches after removal, and 20 is an interpolation unit outside the range of the second variable threshold value from the weighted average value of the left and right four pixels for dark current abnormality and noise removal. Is a first variable threshold value determination unit, which is a noise average unit having a power cycle of 2 (about 8 pixels) and a horizontal shading component average unit.
In FIG. 4A, 14a to 14p flip-flops, 12a to 12r adders, and 15 bit shift division units generate weighted average interpolation signals of 4 pixels on the left and right. Then, the first variable threshold value determination unit 21 and the second variable threshold value out-of-range determination unit 22 control the weighted average interpolation of the left and right four pixels. The 14a-14p flip-flops, 12a-12r adders, and 15 bit shift division units average noise of 2 power cycles (about 8 pixels).

  In FIG. 5A, (a) Schematic diagram of V-OB value, (b1) V-OB waveform with fixed pattern noise (vertical streak component) removed in power-of-two pixel period and activation (for removing white scratches and black scratches) Schematic diagram of the first variable interpolation threshold with the first edge wide and the second half narrow, (b2) V-OB waveform with vertical streak component removed, and upper and lower of normal H-Shading waveform (for removing white scratches and black scratches) (C) Schematic diagram of the first interpolation variable threshold value, (c) Schematic diagram of the V-OB waveform from which the vertical streak component is removed, and the second interpolation variable threshold value (for dark current abnormality and noise removal), (d) After LPF It is the schematic diagram of a waveform, (e) The schematic diagram of the H-Shading waveform which added the vertical stripe component.

  4A and 5A, after removing fixed pattern noise (vertical streak component) with a power-of-two pixel period, when starting at low temperature, as shown in FIG. 5A (b1), the gain and H-shading components are matched. At the time of start-up, the first variable threshold value out-of-range interpolation section having a wide initial edge and a narrow latter half interpolates white scratches and black scratches with significant levels by weighted average values of left and right four pixels. Normally, as shown in Fig. 5A (b2), this is the first interpolation variable threshold out-of-range interpolation section that is far away from the H-Shading waveform. Most white and black scratches are weighted averages of the left and right four pixels. Interpolate by value. In addition, in order to remove dark current anomalies and noises that are slightly apart from the weighted average value of the left and right four pixels (a little apart from the H-Shading waveform) and outside the second variable threshold range, Interpolated by weighted average value, averaged noise of 2 power cycles (about 8 pixels), added and averaged in line memory, and after removing offset, fixed pattern noise (vertical stripe component) of 2 power pixels cycle ) Is used as a horizontal shading correction signal.

That is, the second embodiment utilizes the fact that the temperature of the CCD and peripheral circuits is low and the horizontal shading is large but the level of white scratches is low when starting at a low temperature. When the temperature of the CCD or the peripheral circuit is low, the horizontal shading is large, but since the level of white scratches is low, the horizontal shading correction error is small. When the temperature of the CCD or the peripheral circuit is high, the horizontal shading is small. Therefore, even if the level of white scratches is high, the horizontal shading correction error is small.
You may acquire and utilize the temperature information of CCD or a peripheral circuit from CCD, the surrounding temperature sensor information, and the average value of V-OB.

  Hereinafter, the H-Saw component, the H-Top-Frame component, and the H-Saw component after removing the fixed pattern noise (vertical stripe component) of the power-of-two pixel period of one embodiment of the present invention will be described. FIG. 4B is a block diagram showing a circuit configuration of a real-time horizontal shading component detection unit (for detecting and combining ringing components), and a schematic diagram showing component detection and synthesis of the real-time horizontal shading component detection unit according to an embodiment of the present invention. FIG. 5B is used to explain the difference from the second embodiment.

In FIG. 4B of the block diagram illustrating the circuit configuration of the real-time horizontal shading component detection unit according to an embodiment of the present invention, the light is shielded immediately after the removal of the vertical streak component and before the power supply turn-off at the time of dark part adjustment or the power supply turn-off. After removing the white scratches memorized in this way, from the cubic curve value of the left and right 4 pixels, the second variable threshold out-of-range interpolation unit, the noise averaging unit more than the ringing period (about 32 pixels), horizontal sawtooth (H- Saw) component, horizontal image rising edge (H-Top-Frame) component and horizontal ringing (H-ringing) component detection and synthesis, 22 is the range of the second variable threshold from the cubic curve value of the left and right 4 pixels An external determination unit 23 is an H-SAW detection unit.
4B, 14a-14p flip-flops, 12a-12i adders, 17a-17f subtractors, and 15 bit shift division units generate cubic curve value interpolation signals of 4 pixels on the left and right. . Then, the third curve value interpolation of the left and right four pixels is controlled by the white flaw information and the second variable threshold out-of-range determination unit from the cubic curve values of 22 left and right four pixels. In addition, the flip-flops of 14a to 14p and 14ζ to 14η, the adders of 12a to 12r and 12ε to 12η, and the 15 bit shift division unit perform noise averaging over the ringing period (about 32 pixels).

  5B, (a) a schematic diagram of the V-OB value, (b) a schematic diagram of a V-OB waveform from which fixed pattern noise (vertical streak component) having a power of 2 pixel periods is removed, and (c) a vertical streak component and It is a V-OB waveform from which white scratches are removed, (d) a schematic diagram of an H-Saw component, (e) a schematic diagram of an H-Top-Frame component, and (f) a schematic diagram of an H-Ringing component.

  In FIG. 4B and FIG. 5B, after removing fixed pattern noise (vertical streak component) having a power-of-two pixel period, there is only one scanning line that is shielded from light before dark power adjustment during light shielding or immediately before power-off at power-off. -OB white scratches are memorized, white scratches are interpolated with a cubic curve value of 4 pixels on the left and right, and are interpolated outside the range of the second variable threshold from the cubic curve values of the 4 pixels on the left and right, and the ringing period or more (about 32 pixels) ) Noise average, the definite integral of the average of the differences is the HSAW component, the HSAW component is subtracted from the noise averaged signal longer than the ringing period (about 32 pixels), and the horizontal image rises (H-Top-Frame) ) The component is extracted, and the HSAW component and the H-Top-Frame component are subtracted from the signal interpolated outside the range to extract the horizontal ringing (H-ringing) component.

  4B and 5B, after adding the horizontal ringing (H-ringing) component, the horizontal rising edge (H-Top-Frame) component, and the horizontal sawtooth (H-Saw) component to remove the offset A signal obtained by adding fixed pattern noise (vertical streak component) having a power-of-two pixel period is used as a horizontal shading signal.

1: Television camera, 2: Lens, 3: Prism,
4R, 4G, 4B: CCD, 5R, 5G, 5B: CDS, 6R, 6G, 6B: VGA,
7R, 7G, 7B: A / D converter,
8: Video signal processing unit,
8A: Video signal processing unit with a real-time shading correction function,
9: Video signal output unit, 10: TG, 11: CPU,
12a to 12r, 12ε to 12η: adders, 13a to 13d: switches,
14a-14p, 14ζ-14η: flip-flop,
15: bit shift division unit, 16: offset removal unit, 17a to 17f: subtractor,
18: Horizontal shading component detection unit,
19: a first variable threshold out-of-range interpolation unit;
20: Out of range interpolation unit of second variable threshold from weighted average value of left and right 4 pixels,
21: First variable threshold value determination unit,
22: a second variable threshold out-of-range determination unit from a cubic curve value of left and right four pixels,
23: H-SAW detector,

Claims (2)

In an imaging device using a solid-state imaging device having vertical optical black (Vertical-Optical Black: V-OB),
Subtract fixed pattern noise (vertical streak component) with a power-of-two pixel period from the V-OB signal, and shift the pixel signal outside the first variable threshold range according to the amplification level and horizontal shading (H-shading). as a horizontal shading (H-shading) correction signal is 4 pixels (the weighted average value or cubic curve value) interpolating calculation value, which is subtracted from the effective pixel signal,
After interpolating the pixel signal outside the range of the first variable threshold according to the amplification degree and horizontal shading (H-shading) with a cubic curve value of four left and right pixels, the V-OB signal is converted into a horizontal sawtooth (H -Saw) component and horizontal image rising portion (H-Top-Frame) component and horizontal ringing (H-ringing) component are decomposed into components, and the composition of each component is converted into a horizontal shading correction signal. An imaging apparatus characterized by the above . 2. The imaging apparatus according to claim 1, wherein the V-OB white scratch is stored by shading immediately before dark power adjustment when the light is shielded or immediately before the power is turned off when the power is turned off, and the white scratch is interpolated with the calculated values of the left and right pixels. An imaging device that is characterized .

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