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US 4,903,121 AGranted
Image pick up apparatus having pixel compensation circuit
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsKenya Uomori, Atsushi Morimura, Yoshinori Kitamura
Life of this patent
Estimating the term…
Abstract
In an image pick up apparatus having an image pick up device (1), an amplifier (2), a vertical contour compensation circuit (500), a gamma correction circuit (8), a horizontal contour compensation circuit (9), a color operation circuit (200), and an encoder (10), pixel compensation circuits (100, 100') are provided for reducing modulation components are caused by a color filter during saturation in an image pick up device (1). Horizontal low-pass circuits (7a, 7b) combined with clippers (24a, 24b) are provided in the vertical contour compensation circuit (500) to reduce a modulation components caused by such compensation in the pixel compensation circuits (100, 100').
Claims25
An image pick-up apparatus comprising:
- (a) an image pick up device means for picking up an image and for producing a pixel signal indicative of said image;
- (b) a 1-H delay circuit means responsive to said pixel signal from said image pick up device means for delaying said pixel signal by 1H;
- (c) a first pixel compensation circuit means responsive to an output signal from said 1-H delay circuit means for generating a first weighted signal;
- (d) a second pixel compensation circuit means responsive to said pixel signal from said image pick up device means for generating a second weighted signal;
- (e) a vertical contour compensation circuit means for emphasizing contours defined by said first and second weighted signals, thereby producing a vertical contour compensation signal;
- (f) a first adder means for adding said first weighted signal to said second weighted signal;
- (g) a horizontal low-pass circuit means responsive to an output signal from said first adder means;
- (h) a second adder means for adding an output signal from said horizontal low-pass circuit means to said vertical contour compensation signal;
- (i) a circuit means responsive to an output signal from said second adder means to generate a luminance signal;
- (j) a color operation circuit means responsive to said pixel signal from said image pick up device means and to said output signal from said 1-H delay circuit means for generating color difference signals;
- and
- (k) an encoder means responsive to said luminance signal and said color difference signals for obtaining a video signal.
9 more elements
An image pick up apparatus comprising:
- (a) a first image pick up device means having a green color filter for generating a first pixel signal;
- (b) a second image pick up device means having a red and blue color filter for generating a second pixel signal;
- (c) a red and blue signal separating circuit means responsive to an output signal from said second image pick up device means for separating said output signal from said second image pick up device means into a red signal and a blue signal;
- (d) a color signal processing circuit means responsive to said first pixel signal from said first image pick up device means, said red signal, and said blue signal for producing color difference signals;
- (e) a pixel compensation circuit means responsive to said second pixel signal from said second image pick up device means for providing a weighted signal;
- (f) a first adder means for adding said weighted signal to said first pixel signal from said first image pick up device means;
- (g) a 1-H delay circuit means responsive to an output signal from said first adder means for producing a delayed signal;
- (h) a vertical contour compensation circuit means for emphasizing contours defined by an output signal from said first adder means and said delayed signal, thereby producing a vertical contour compensation signal;
- (i) a second adder means for adding said output signal from said first adder means to said delayed signal from said 1-H delay circuit means;
- (j) a horizontal low-pass circuit means responsive to an output signal from said second adder means;
- (k) a third adder means for adding an output signal from said horizontal low-pass circuit means to said vertical contour compensation signal;
- (l) a circuit means responsive to an output signal from said third adder means to obtain luminance signal;
- and
- (m) an encoder means responsive to said luminance signal and said color difference signals for obtaining a video signal.
11 more elements
An image pick up apparatus comprising:
- (a) an image pick up section including:
- an image pick up device for picking up an image and for producing a pixel signal;
- an amplifier responsive to said pixel signal for amplifying said pixel signal and for producing an amplified pixel signal;
- a color temperature detecting circuit means for detecting color temperature values of said image and for producing color temperature signals each indicative of each of said color temperature values:
- a color temperature-clip level converter means responsive to said color temperature signals for converting said color temperature signals into clip level signals indicative of clip levels each corresponding to each of said color temperature values;
- and
- a clipper means for clipping said amplified pixel signal in accordance with said clip level signals and for producing a clipped signal representing an output signal of said image pick up section;
- (b) a pixel compensation circuit means responsive to said output signal from said image pick up section for providing a weighted signal;
- (c) a 1-H delay circuit means responsive to an output signal from said pixel compensation circuit means for delaying said weighted signal from said pixel compensation circuit means by 1H producing a second weighted signal;
- (d) a vertical contour compensation circuit means for emphasizing contours defined by said first and second weighted signal by producing a vertical contour compensation signal;
- (e) a horizontal low-pass circuit means responsive to said weighted signal from said pixel compensation circuit means;
- (f) an adder means for adding said vertical contour compensation signal from said vertical contour compensation circuit means to an output signal from said horizontal low-pass circuit means;
- (g) a circuit means responsive to an output signal from said adder means to obtain a luminance signal;
- (h) a color signal generating circuit means responsive to said output signal from said image pick up section for producing color difference signals;
- and
- (i) an encoder means responsive to said luminance signal and said color difference signals for obtaining a video signal.
13 more elements
An image pick up apparatus comprising:
- (a) an image pick up including:
- an image pick up device for picking up an image and for producing a pixel signal;
- an amplifier responsive to said pixel signal for amplifying said pixel signal and for producing an amplified pixel signal;
- a color temperature detecting circuit means for detecting color temperature values of said image and for producing color temperature signals each indicative of each of said color temperature values;
- a color temperature-clip level converter means responsive to said color temperature signals for converting said color temperature signals into clip level signals indicative of clip levels each corresponding to each of said color temperature values, and for outputting said clip level signals;
- and
- a clipper means for clipping said amplified pixel signal in accordance with said clip level signals and for producing a clipped signal representing an output signal of said image pick up section;
- (b) a 1-H delay circuit means responsive to said output signal from said image pick up deice means for delaying said output signal from said image pick up section by 1H;
- (c) a vertical contour compensation circuit means for emphasizing contours defined by said output signal from said image pick up section and an output signal from said 1-H delay circuit means, thereby producing a vertical contour compensation signal, said vertical contour compensation circuit means including:
- (i) a subtracter means responsive to said output signal from said image pick up section and said output signal from said 1-H delay circuit means for subtracting said output signal of said image pick up section from said output signal of said 1-H delay circuit means;
- and
- (ii) a first horizontal low-pass circuit means responsive to an output signal from said subtracter means for obtaining said vertical contour compensation signal;
- (d) a first adder means for adding said output signal from said image pick up section to said output signal from said 1-H delay circuit means;
- (e) a second horizontal low-pass circuit means responsive to an output signal from said first adder means;
- (f) a second adder means for adding said vertical contour signal to an output signal from said second horizontal low-pass circuit means;
- (g) a circuit means responsive to an output signal from said second adder means to obtain a luminance signal;
- (h) a color operation circuit means responsive to said output signal from said image pick up section and said output signal from said 1-H delay circuit means for producing color difference signals;
- and
- (i) an encoder means responsive to said luminance signal and said color difference signals for obtaining a video signal.
16 more elements
An image pick up apparatus comprising:
- (a) an image pick up section including:
- an image pick up device for picking up an image and for producing a pixel signal representing said image;
- an amplifier responsive to said pixel signal for amplifying said pixel signal and for producing an amplified pixel signal;
- a color temperature detecting circuit means for detecting color temperature values of said image and for producing color temperature signals each indicative of each of said color temperature values;
- a color temperature-clip level converter means responsive to said color temperature signals for converting said color temperature signals into clip level signals indicative of clip levels each corresponding to each of said color temperature values, and for generating said clip level signals;
- and
- a clipper means for clipping said amplified pixel signal in accordance with said clip level signals and for producing a clipped signal representing an output signal of said image pick up section;
- (b) a 1-H delay circuit means responsive to said output signal from said image pick up device section for delaying said output signal from said image pick up section by 1H;
- (c) a vertical contour compensation circuit means for emphasizing contours defined by said output signal from said image pick up section and an output signal from said 1-H delay circuit means, thereby producing a vertical contour compensation signal, said vertical contour compensation circuit means including:
- (i) a first horizontal low-pass circuit means responsive to said output signal from said image pick up section;
- (ii) a second clipper means for clipping an output signal from said first horizontal low-pass circuit means in accordance with a predetermined clip value;
- (iii) a second horizonal low-pass circuit means responsive to said output signal from said 1-H delay circuit means;
- (iv) a third clipper means for clipping an output signal from said second horizontal low-pass circuit means in accordance with said predetermined clip value;
- and
- (v) a second subtracter means for subtracting an output signal of said second clipper means from an output signal of said third clipper means and for feeding a subtracted signal thereof to said second adder means;
- (d) a first adder means for adding said output signal from said image pick up section to said output signal from said 1-H delay circuit means;
- (e) a third horizontal low-pass circuit means responsive to an output signal from said first adder means;
- (f) a second adder means for adding said vertical contour signal to an output signal from said third horizontal low-pass circuit means;
- (g) a circuit means responsive to an output signal from said second adder means to obtain a luminance signal;
- (h) a color operation circuit means responsive to said output signal from said image pick up section and said output signal from said 1-H delay circuit means for producing color difference signals;
- and
- (i) an encoder means responsive to said luminance signal and said color difference signals for obtaining a video signal.
19 more elements
An image pick up apparatus comprising:
- (a) an image pick up section including:
- (i) an image pick up device for picking up an image and for producing a pixel signal;
- and
- (ii) an amplifier responsive to said pixel signal for amplifying said pixel signal and for producing an amplified pixel signal indicative of an output signal from said image pick up section;
- (b) a 1-H delay circuit means responsive to said output signal from said image pick up section for delaying said output signal from said image pick up section by 1H;
- (c) a first selector means responsive to said output signal from said image pick up section and an output signal from said 1-H delay circuit means for selecting one signal which is to be compensated and for providing said one signal and the other signal, said first selector means having a first input terminal to which said output signal from said image pick up section is received and a second input terminal to which said output signal from said 1-H delay circuit means is received;
- (d) a pixel compensation circuit means responsive to said one signal from said first selector means for providing a weighted signal, said pixel compensation circuit means including:
- (i) a pixel weighting circuit means responsive to said one signal from said first selector means for weighting said one signal from said first selector means;
- and
- (ii) a band separating operation circuit means for weighting a high-frequency component signal in said one signal from said first selector means, said first band separating operation circuit means having:
- a horizontal high-pass circuit means responsive to an output signal from said pixel weighting circuit means;
- a first horizontal low-pass circuit means responsive to said one signal from said first selector means;
- and
- a first adder means for adding an output signal from said horizontal high-pass circuit means to an output signal from said first horizontal low-pass circuit means to provide said weighted signal;
- (e) a second selector means responsive to said weighted signal and said other signal from said first selector means for providing said weighted signal and said other signal from said first selector means such that said weighted signal is provided from a first terminal of said second selector means when said one signal which is to be compensated is received by said first terminal of said first selector means, and that said weighted signal is provided from said second terminal of said second selector means when said one signal which is to be compensated is received by said second terminal of said first selector means;
- (f) a vertical contour compensation circuit means to produce a vertical contour compensation signal for emphasizing contours defined by output signals from said first and second terminals of said second selector means, said vertical contour compensation circuit means including:
- (i) a subtracter means responsive to said output signals from said first and second terminals of said output signals from said first and second terminals of said second selector means for subtracting said output signal of said second terminal of said second selector means from said output signal from said first terminal of said second selector means;
- and
- (ii) a horizontal low-pass circuit means responsive to an output signal from said subtracter means for obtaining said vertical contour compensation signal;
- (g) an adder means for adding said output signals from said first and second terminals of said second selector means to each other;
- (h) a horizontal low-pass circuit means responsive to an output signal from said second adder means;
- (i) a second adder means for adding an output signal from said horizontal low-pass circuit means to said vertical contour compensation signal;
- (j) a circuit means responsive to an output signal from said second adder means to obtain a luminance signal;
- (k) a color operation circuit means responsive to said output signal from said image pick up device means and said output signal from said 1-H delay circuit means for obtaining color difference signals;
- and
- (l) an encoder means responsive to said luminance signal and said color difference signals for obtaining a video signal.
23 more elements
Dependencies are inferred from the claim text.