JP3820608B2 - Video signal processing circuit - Google Patents

Description

【００１９】
これに対し、垂直成分をＹVとして求めると、次の（2）のようになる。
【数２】

【００２０】
この垂直成分ＹVを、次の（3）式のように、ある係数αを積算して前記輝度信号ＹA’，ＹB’に加算し、最終的な輝度信号ＹA，ＹBを得る。そして、それらの差分であるＹA−ＹBが、輝度垂直差分回路４０から出力される。
【数３】

【００２１】
セットアップ回路３８の出力信号は、γ補正回路２４によるγ補正の後、垂直成分補正回路４２に供給される。他方、輝度垂直差分回路４０による差分信号は、ベースクリップ回路４４によるベースクリップ処理の後、アンプ４６でＫ倍され、垂直成分補正回路４２に供給される。垂直成分補正回路４２では、Ｋ倍された差分信号Ｋ×（ＹA−ＹB）によって入力信号ＹHが補正され、補正後の輝度信号ＹWが出力される。この輝度信号ＹWは、アパーチャ補正回路４８，１Ｈ遅延回路５０，５２によって、水平，垂直方向のアパーチャ補正が行われ、その後コアリング回路５４によるコアリング及び輝度のゲイン処理，加算器５６による遅延信号加算の後、最終的な輝度信号ＹWとして出力される。
【００２２】
このように、本実施例によれば、２ライン加算が行われるため、ｆs／２のモワレが相殺されるようになり、水平解像度が向上する。また、垂直成分が補正されるため、垂直解像度も向上する。更に、Ｒ，Ｂの原色フィルタを用いているため、色再現性にも優れている。
【００２３】
【実施例２】
次に、図３，図４を参照しながら実施例２について説明する。図３には、実施例２における色フィルタ配列が示されている。同図に示すように、基本的な配列自体は、上述した図８の背景技術と同様であるが、透明フィルタＷ'の分光特性が異なる。すなわち、本実施例では、図９（A）に示した分光特性ではなく、図４にグラフＧＡで示した分光特性となっている。同図中、シアンフィルタＣyはグラフＧＢ，イエローフィルタＹeはグラフＧＣ，緑フィルタＧはグラフＧＤである。本実施例の透明フィルタＷ'は、それらＣy，Ｙe，Ｇに対して、次の（4）式で表わされる。
【００２４】
【数４】

なお、この（4）式中、「＋」は、フィルタの重ね合わせではなく、平均透過率を表わす。
【００２５】
この結果、透明フィルタＷ'は、短波長側で感度の少ないフィルタとなる。また、緑フィルタＧは、一般にシアンフィルタＣｙとイエローフィルタＹｅの重ね合わせで構成していたが、グラフＧＤで示す緑フィルタＧ単独で構成してもよい。以上のような分光感度特性を有するフィルタＷ'，Ｇ，Ｃy，Ｙeを図３に示すように配列することによってフィルタアレイが構成されている。
【００２６】
次に、図５を参照しながら本実施例の信号処理回路について説明する。図３の色フィルタ配列の撮像素子（図示せず）から出力された映像信号のうち、１ラインで輝度信号が構成され、２ラインで色信号が構成される。例えば、第１フィールドの輝度信号，すなわち図３に示すラインｎ，ｎ+2，……の輝度信号ＹAは、（5）式で表わされる。また、第２フィールドの輝度信号，すなわち図３に示すラインｎ+1，ｎ+3，……の輝度信号ＹBは、（6）式で表わされる。これらをグラフで示すと、図４のＧＥのようになる。
【００２７】
【数５】

【数６】

【００２８】
他方、色信号は、次の（7）〜（9）式のようにして求められる。
【数７】

【数８】

【数９】

【００２９】
これらの信号が図５のＯＢクランプ回路１０から出力される。これらのうち、色信号は画素補間回路６０に供給され、ここで各画素出力に対する画素補間処理が行われた信号がマトリクス回路６２に供給される。マトリクス回路６２によるマトリクス処理によって得られた映像信号ＲL，ＧL，ＢLは、ホワイトバランス回路６４によるホワイトバランス処理，γ補正回路６６によるγ補正の後、他のマトリクス回路６８に供給される。そして、マトリクス回路６８によるマトリクス処理によって色差信号ＲL−ＹL，ＢL−ＹLが得られる。これら色差信号は、色差ゲイン回路７０において、色成分に生じた偽信号が除去された後ベースクリップ回路３６に供給され、最終的な色差信号ＲL−ＹL，ＢL−ＹLが得られる。
【００３０】
他方、各フィールドの輝度信号ＹA，ＹBは、セットアップ回路７２によるセットアップ処理の後にトラップフィルタ７６に供給される。トラップフィルタ７６では、ｆｓ／２トラップの処理が行われ、処理後の信号がγ補正回路６６によるγ補正の後にフィールド／フレームメモリ７８に供給される。フィールド／フレームメモリ７８では、映像もしくは状況に応じたフィールド／フレーム切換えの処理が行われる。そして、処理後のフィールドもしくはフレームの信号に対して、前記実施例１と同様のアパーチャ補正が行われ、加算器５６から最終的な輝度信号ＹWが出力される。
【００３１】
ところで、本実施例によれば、透明フィルタＷ'の分光特性が図４に示したように設定されている。これにより、Ｗ'，Ｇの色フィルタの平均透過率とＣy，Ｙeの色フィルタの平均透過率が同じになり、図１０に斜線で示すような分光感度差が生じない。このため、インターレースモニター時のフリッカ，あるいは、ノンインターレースモニタープリンタによるフレーム信号に基づくプリントアウトなどにおけるラインフロークが低減され、４８０本程度の垂直解像度の映像が得られる。また、図５に示したように、フィールドもしくはフレームメモリを撮像機器内に設け、ライン毎に輝度信号を構成することとしたので、フィールド間のずれのないフレームスチル映像を撮像することが可能となる。更に、本実施例によれば、マトリクスによる信号処理が容易となるため、マトリクス回路の構成が簡略化できる。
【００３２】
【他の実施例】
この発明には数多くの実施の形態があり、以上の開示に基づいて多様に改変することが可能である。例えば、次のようなものも含まれる。
（1）Ｗ'，Ｇ，Ｃy，Ｙeのフィルタを組み合わせる配列としては、前記実施例２の他に、図６（A）〜（C）に示すものが考えられ、いずれも前記実施例２と同等の効果を得ることができる。
（2）本発明は、全画素読出方式の撮像素子を用いれば適用可能であり、いわゆる単板方式，双板方式には左右されない。
（3）前記実施例に示した色信号処理方法や処理装置は、必要に応じて適宜変更してよく、何ら前記実施例に限定されるものではない。
【００３３】
【発明の効果】
以上説明したように、この発明によれば、次のような効果がある。
（１）２ライン加算が行われるため、ｆｓ／２のモワレが相殺されるようになり、水平解像度が向上する。
（２）垂直成分が補正されるため、垂直解像度も向上する。
（３）Ｒ，Ｂの原色フィルタを用いているため、色再現性にも優れている。
（４）垂直成分補正信号の生成には、トラップ回路により異なる１ライン毎にＹのフィルタの画素位置に対応する輝度信号を取り出し、この取り出されたラインとそれに連続するラインのＹのフィルタの画素位置に対応する輝度信号であって、互いに斜め方向に隣接する輝度信号を一対として用いているため斜め方向のモワレについても軽減することができる。
【図面の簡単な説明】
【図１】この発明の実施例１の色フィルタ配列を示す図である。
【図２】実施例１の信号処理回路を示すブロック図である。
【図３】この発明の実施例２の色フィルタ配列を示す図である。
【図４】実施例２の色フィルタの分光特性を示すグラフである。
【図５】実施例２の信号処理回路を示すブロック図である。
【図６】この発明の他の実施例の色フィルタ配列を示す図である。
【図７】従来の色フィルタ配列の一例を示す図である。
【図８】従来の色フィルタ配列の一例を示す図である。
【図９】従来の色フィルタ配列の分光特性を示すグラフである。
【図１０】従来の色フィルタ配列におけるライン間の輝度信号の分光感度差を示すグラフである。
【符号の説明】
Ｒ…赤フィルタ
Ｇ…緑フィルタ
Ｂ…青フィルタ
Ｗ，Ｗ'…透明フィルタ
Ｃｙ…シアン
Ｙｅ…イエロー
Ｙ…輝度フィルタ
１０…ＯＢクランプ回路
１２…色分離回路
１４…２ライン混合回路
１６，１８…トラップ回路
２０…ＬＰＦ
２２，６４…ホワイトバランス回路
２４，６６…γ補正回路
２６，６２，６８…マトリクス回路
２８，７０…色差ゲイン回路
３０…１Ｈディレイ回路
３２，３４，５６…加算器
３６…ベースクリップ回路
３８，７２…セットアップ回路
４０…輝度垂直差分回路
４２…垂直成分補正回路
４４…ベースクリップ回路
４６…アンプ
４８…アパーチャ補正回路
５０，５２…１Ｈディレイ回路
５４…コアリング回路
６０…画素補間回路
７６…トラップフィルタ
７８…フィールド／フレームメモリ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video signal processing circuit of an image sensor, and more specifically, relates to an improvement of a video signal processing circuit suitable for an all-pixel readout type solid-state image sensor.
[0002]
[Background art and problems to be solved by the invention]
As a filter array of an imaging apparatus using a solid-state imaging device such as a CCD, there is an array in which primary color filters of R (red), G (green), and B (blue) are arranged. FIG. 7 shows an example of a primary color filter array in an image sensor of an all-pixel readout method, in which green filters G are arranged in a checkered pattern, and red filters R and blue filters B are arranged in the remaining part. ing. In this method, the luminance signal is synthesized from the R, G, and B signals in two rows.
[0003]
For example, in the first field, a luminance signal is generated by combining the nth line signal and the (n + 1) th line signal, the (n + 2) th line signal and the (n + 3) th line signal, and so on. The In the second field, a luminance signal is generated by combining the signal of the (n + 1) th line and the signal of the (n + 2) th line, the signal of the (n + 3) th line and the signal of the (n + 4) th line, and so on. The
[0004]
However, the background art as described above has the following disadvantages.
(1) If the frequency of the color subcarrier is fs, a color moire of fs / 2 is mixed in the luminance signal, resulting in deterioration of the horizontal resolution.
(2) Since only a luminance signal obtained by mixing two lines of signals is used, the vertical resolution is insufficient. For example, the vertical resolution is about 350 lines.
(3) Since the primary color filter is used, the light utilization rate is poor and the sensitivity is insufficient.
[0005]
Next, in an image pickup apparatus using a conventional single-plate image pickup device (IL-CCD), an Mg (magenta) color filter is generally used to mix two lines into a luminance signal. Before the color filter array is composed of four colors of Mg, G, Cy (cyan), and Ye (yellow) as in the present, a method using four colors of W (transparent), G, Cy, and Ye is also available. Although devised (see Japanese Patent Application Laid-Open No. Sho 62-108694) and commercially available, there is no such system for making a luminance signal in one line in such a four-color system of W, G, Cy, and Ye. FIG. 8 shows the color filter arrangement of the above publication, in which a line constituted by G and W filters and a line constituted by Cy and Ye filters are alternately arranged. Yes.
[0006]
By the way, since the transparent filter W is a system that does not use a color filter, the pixel output of the transparent filter W portion becomes the spectral characteristics of the solid-state imaging device. FIG. 9A shows an example of the characteristics of the transparent filter W, where the horizontal axis represents wavelength and the vertical axis represents relative sensitivity. In FIG. 5B, the characteristics of other filters G, Cy, Ye are shown for reference.
[0007]
Here, consider a case where a luminance signal is obtained with one line in the color filter array of FIG. If the luminance signal by the W and G lines is YA and the luminance signal by the Cy and Ye lines is YB, for example, the characteristics shown in FIG. 10 are obtained, and a spectral sensitivity difference is generated as shown by hatching in FIG.
[0008]
As a result, when the luminance signal YA is used for the field A and the luminance signal YB is used for the field B, even if both levels are matched when imaging a monochrome subject, the subject having a wavelength in the hatched range, that is, B or Flickers in the field period (1/60 second in the case of the NTSC system) occur in the R subject portion due to the level difference of the luminance signal for each field. Furthermore, when printing out based on the luminance signal or displaying on a non-interlace monitor, a line cloaking phenomenon appears.
[0009]
The present invention focuses on the above points, and a first object is to improve the horizontal and vertical resolutions and to obtain good sensitivity.
The second object is to reduce the occurrence of flicker during interlace monitoring, to reduce line cloaking in printouts based on frame signals in a non-interlace monitor printer, and to obtain frame still images with no shift between fields. That is.
[0010]
[Means for Solving the Problems]
The present invention comprises the following means in order to solve the above problems.
That is,
Image used for an all-pixel readout type solid-state imaging device having a color filter array in which Y filters are arranged in a checkered pattern, and R and B filters are arranged in the same line and alternately between lines. In the signal processing circuit,
A line mixing circuit for generating a luminance signal YH by mixing video signals sequentially coming from the solid-state image sensor as a pair of signals for every two lines;
First and second trap circuits for performing fs / 2 trap processing for extracting a luminance signal corresponding to a pixel position of the Y filter for each different line from the incoming video signal;
A luminance signal corresponding to the pixel position of the Y filter on the first line taken out and the second line continuous thereto, and a signal obtained by subtracting a signal obtained by adding a pair of luminance signals adjacent to each other in a diagonal direction. And adding the signal obtained by multiplying the added signal and the subtracted signal by a predetermined coefficient to generate a luminance vertical difference signal in the first vertical direction,
A luminance signal corresponding to the pixel position of the Y filter of the extracted second line and the third line continuous thereto, and a signal obtained by adding and subtracting a signal obtained by adding a pair of luminance signals adjacent to each other diagonally And adding a signal obtained by multiplying the added signal and the subtracted signal by a predetermined coefficient to generate a second vertical vertical luminance difference signal,
A luminance vertical difference circuit for generating a first third luminance vertical difference signal in the vertical direction from the vertical direction of the luminance vertical difference signal by subtracting the luminance vertical difference signal of the second vertical the generated,
A vertical component correction circuit for correcting the luminance signal YH generated by the line mixing circuit with the third vertical luminance vertical difference signal generated by the luminance vertical difference circuit to generate a final luminance signal YW. When,
A video signal processing circuit comprising:
[0012]
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the invention will be described in detail with reference to examples.
[Example 1]
FIG. 1 shows a color filter arrangement according to this embodiment. In the figure, luminance filters Y (Y = R + G + B) are arranged in a checkered pattern, and red filters R and blue filters B are arranged in the remaining part. That is, as compared with the background art, the luminance filter Y is arranged instead of the green filter G, and the red filter R and the green filter G are line-sequentially arranged.
[0014]
FIG. 2 shows a signal processing circuit for processing a video signal output from an image pickup device (not shown) such as a CCD having such a filter array of color filters. The video signal output from the image sensor is clamped for each line by the OB clamp circuit 10 and then supplied to the color separation circuit 12, the two-line mixing circuit 14, and the trap circuits 16 and 18, respectively.
[0015]
First, the color difference signal processing will be described. In the color separation circuit 12, Yr, Yb, R, and B signals are separated from the input signal and supplied to the LPF 20. Yr is a luminance signal obtained from the line including the red filter R, and Yb is a luminance signal obtained from the line including the blue filter B. In the LPF 20, filter processing for color signal processing is performed.
[0016]
Of the processed video signals YLr, YLb, RL, and BL, RL and BL are supplied to a WB (white balance) circuit 22 and are supplied to a γ correction circuit 24 after the processing. The video signals YLr and YLb are supplied from the LPF 20 to the γ correction circuit 24 as they are. The video signals YLr, YLb, RL, and BL that have been subjected to the γ correction by the γ correction circuit 24 are supplied to the matrix circuit 26, where they are subjected to matrix processing to obtain color difference signals RL-YLr and BL-YLb. These color-difference signals are processed by the 1H (one-line) delay circuit 30 and the adder 32 and 34 in the upper and lower lines after the false signal such as the folding signal or moire generated in the color component is removed in the color-difference gain circuit 28. Is added. The added color difference signals are output as color difference signals RL-YL and BL-YL after S / N improvement by the base clip circuit 36.
[0017]
Next, luminance signal processing will be described. In the two-line mixing circuit 14, signals of two continuous lines are mixed. For example, in the first field, the nth line signal and the (n + 1) th line signal, the n + 2 line signal and the (n + 3) line signal, and so on are mixed. In the second field, The luminance signal YH is generated by mixing the signal of the (n + 1) th line and the signal of the (n + 2) th line, the signal of the (n + 3) th line and the signal of the (n + 4) th line, and so on. The luminance signal YH thus obtained is supplied to the setup circuit 38, where the setup component is added to the luminance signal.
[0018]
On the other hand, the video signal subjected to the fs / 2 trap processing by the trap circuits 16 and 18 is supplied to the luminance vertical difference circuit 40, where the following processing is performed. Assuming that the luminance signal of the first field obtained by the above-mentioned two-line mixing is YA ′ and the luminance signal of the second field is YB ′, the following equation (1) is obtained.
[Expression 1]

[0019]
On the other hand, when the vertical component is obtained as YV, the following (2) is obtained.
[Expression 2]

[0020]
The vertical component YV is added to the luminance signals YA ′ and YB ′ by adding a certain coefficient α as shown in the following equation (3) to obtain final luminance signals YA and YB. Then, YA−YB which is a difference between them is output from the luminance vertical difference circuit 40.
[Equation 3]

[0021]
The output signal of the setup circuit 38 is supplied to the vertical component correction circuit 42 after γ correction by the γ correction circuit 24. On the other hand, the difference signal from the luminance vertical difference circuit 40 is subjected to base clip processing by the base clip circuit 44, multiplied by K by the amplifier 46, and supplied to the vertical component correction circuit 42. In the vertical component correction circuit 42, the input signal YH is corrected by the difference signal K × (YA−YB) multiplied by K, and the corrected luminance signal YW is output. The luminance signal YW is subjected to horizontal and vertical aperture corrections by the aperture correction circuit 48 and 1H delay circuits 50 and 52, and thereafter coring and luminance gain processing by the coring circuit 54, and a delay signal by the adder 56. After the addition, the final luminance signal YW is output.
[0022]
As described above, according to this embodiment, since the two-line addition is performed, the moire of fs / 2 is canceled, and the horizontal resolution is improved. Further, since the vertical component is corrected, the vertical resolution is also improved. Further, since the R and B primary color filters are used, the color reproducibility is excellent.
[0023]
[Example 2]
Next, Embodiment 2 will be described with reference to FIGS. FIG. 3 shows a color filter arrangement in the second embodiment. As shown in the figure, the basic arrangement itself is the same as the background art of FIG. 8 described above, but the spectral characteristics of the transparent filter W ′ are different. That is, in this embodiment, the spectral characteristic shown in the graph GA in FIG. 4 is used instead of the spectral characteristic shown in FIG. In the figure, the cyan filter Cy is a graph GB, the yellow filter Ye is a graph GC, and the green filter G is a graph GD. The transparent filter W ′ of this embodiment is expressed by the following equation (4) with respect to Cy, Ye, and G.
[0024]
[Expression 4]

In the equation (4), “+” represents the average transmittance, not the filter superposition.
[0025]
As a result, the transparent filter W ′ is a filter with low sensitivity on the short wavelength side. Further, the green filter G is generally configured by superimposing the cyan filter Cy and the yellow filter Ye, but may be configured by the green filter G alone shown by the graph GD. A filter array is configured by arranging the filters W ′, G, Cy, and Ye having the above spectral sensitivity characteristics as shown in FIG.
[0026]
Next, the signal processing circuit of this embodiment will be described with reference to FIG. Of the video signal output from the image sensor (not shown) having the color filter array shown in FIG. 3, a luminance signal is composed of one line, and a color signal is composed of two lines. For example, the luminance signal of the first field, that is, the luminance signal YA of the lines n, n + 2,... Shown in FIG. Further, the luminance signal of the second field, that is, the luminance signal YB of the lines n + 1, n + 3,... Shown in FIG. These are shown in a graph as GE in FIG.
[0027]
[Equation 5]

[Formula 6]

[0028]
On the other hand, the color signal is obtained as in the following equations (7) to (9).
[Expression 7]

[Equation 8]

[Equation 9]

[0029]
These signals are output from the OB clamp circuit 10 of FIG. Among these, the color signal is supplied to the pixel interpolation circuit 60, and a signal obtained by performing pixel interpolation processing on each pixel output is supplied to the matrix circuit 62. Video signals RL, GL, BL obtained by matrix processing by the matrix circuit 62 are supplied to another matrix circuit 68 after white balance processing by the white balance circuit 64 and γ correction by the γ correction circuit 66. Then, color difference signals RL-YL and BL-YL are obtained by matrix processing by the matrix circuit 68. These color difference signals are supplied to the base clip circuit 36 after the false signals generated in the color components are removed in the color difference gain circuit 70, and final color difference signals RL-YL and BL-YL are obtained.
[0030]
On the other hand, the luminance signals YA and YB of each field are supplied to the trap filter 76 after the setup processing by the setup circuit 72. The trap filter 76 performs fs / 2 trap processing, and the processed signal is supplied to the field / frame memory 78 after γ correction by the γ correction circuit 66. In the field / frame memory 78, a field / frame switching process corresponding to the video or the situation is performed. Then, the aperture correction similar to that in the first embodiment is performed on the processed field or frame signal, and the final luminance signal YW is output from the adder 56.
[0031]
By the way, according to the present embodiment, the spectral characteristic of the transparent filter W ′ is set as shown in FIG. As a result, the average transmittance of the W ′ and G color filters and the average transmittance of the Cy and Ye color filters are the same, and the spectral sensitivity difference as shown by the oblique lines in FIG. 10 does not occur. For this reason, flicker at the time of interlace monitoring or line flow in printout based on a frame signal by a non-interlace monitor printer is reduced, and an image with about 480 vertical resolutions can be obtained. In addition, as shown in FIG. 5, since a field or frame memory is provided in the imaging device and a luminance signal is configured for each line, it is possible to capture a frame still image with no deviation between fields. Become. Furthermore, according to the present embodiment, signal processing by a matrix is facilitated, so that the configuration of the matrix circuit can be simplified.
[0032]
[Other embodiments]
There are many embodiments of the present invention, and various modifications can be made based on the above disclosure. For example, the following are included.
(1) As an arrangement for combining W ′, G, Cy, and Ye filters, in addition to the second embodiment, the arrangement shown in FIGS. 6A to 6C may be considered. The same effect can be obtained.
(2) The present invention can be applied if an all-pixel readout type image sensor is used, and is not affected by the so-called single plate type or double plate type.
(3) The color signal processing method and processing apparatus shown in the above embodiment may be appropriately changed as necessary, and is not limited to the above embodiment.
[0033]
【The invention's effect】
As described above, the present invention has the following effects.
(1) Since the addition of two lines is performed, the moire of fs / 2 is canceled and the horizontal resolution is improved.
(2) Since the vertical component is corrected, the vertical resolution is also improved.
(3) Since R and B primary color filters are used, the color reproducibility is excellent.
(4) For the generation of the vertical component correction signal, a luminance signal corresponding to the pixel position of the Y filter is extracted for each different line by the trap circuit, and the Y filter pixels of the extracted line and the lines following it are extracted. Since the luminance signals corresponding to the positions and adjacent to each other in the oblique direction are used as a pair, the moire in the oblique direction can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a color filter arrangement according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a signal processing circuit according to the first exemplary embodiment.
FIG. 3 is a diagram illustrating a color filter arrangement according to a second embodiment of the present invention.
4 is a graph showing spectral characteristics of a color filter of Example 2. FIG.
FIG. 5 is a block diagram illustrating a signal processing circuit according to a second embodiment.
FIG. 6 is a diagram showing a color filter array according to another embodiment of the present invention.
FIG. 7 is a diagram illustrating an example of a conventional color filter array.
FIG. 8 is a diagram illustrating an example of a conventional color filter array.
FIG. 9 is a graph showing spectral characteristics of a conventional color filter array.
FIG. 10 is a graph showing a spectral sensitivity difference of luminance signals between lines in a conventional color filter array.
[Explanation of symbols]
R ... Red filter G ... Green filter B ... Blue filter W, W '... Transparent filter Cy ... Cyan Ye ... Yellow Y ... Luminance filter 10 ... OB clamp circuit 12 ... Color separation circuit 14 ... Two-line mixing circuits 16, 18 ... Trap Circuit 20 ... LPF
22, 64, white balance circuits 24, 66, γ correction circuits 26, 62, 68, matrix circuits 28, 70, color difference gain circuit 30, 1H delay circuits 32, 34, 56, adder 36, base clip circuits 38, 72 ... setup circuit 40 ... luminance vertical difference circuit 42 ... vertical component correction circuit 44 ... base clip circuit 46 ... amplifier 48 ... aperture correction circuit 50, 52 ... 1H delay circuit 54 ... coring circuit 60 ... pixel interpolation circuit 76 ... trap filter 78 ... Field / frame memory

Claims (1)

Image used for an all-pixel readout type solid-state imaging device having a color filter array in which Y filters are arranged in a checkered pattern, and R and B filters are arranged in the same line and alternately between lines. In the signal processing circuit,
A line mixing circuit for generating a luminance signal YH by mixing video signals sequentially coming from the solid-state image sensor as a pair of signals for every two lines;
First and second trap circuits for performing fs / 2 trap processing for extracting a luminance signal corresponding to a pixel position of the Y filter for each different line from the incoming video signal;
A luminance signal corresponding to the pixel position of the Y filter on the first line taken out and the second line continuous thereto, and a signal obtained by subtracting a signal obtained by adding a pair of luminance signals adjacent to each other in a diagonal direction. And adding the signal obtained by multiplying the added signal and the subtracted signal by a predetermined coefficient to generate a luminance vertical difference signal in the first vertical direction,
A luminance signal corresponding to the pixel position of the Y filter of the extracted second line and the third line continuous thereto, and a signal obtained by adding and subtracting a signal obtained by adding a pair of luminance signals adjacent to each other diagonally And adding a signal obtained by multiplying the added signal and the subtracted signal by a predetermined coefficient to generate a second vertical vertical luminance difference signal,
A luminance vertical difference circuit for generating a first third luminance vertical difference signal in the vertical direction from the vertical direction of the luminance vertical difference signal by subtracting the luminance vertical difference signal of the second vertical the generated,
A vertical component correction circuit for correcting the luminance signal YH generated by the line mixing circuit with the third vertical luminance vertical difference signal generated by the luminance vertical difference circuit to generate a final luminance signal YW. When,
A video signal processing circuit comprising:

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