Image signal correction processing apparatus
AssigneeCanon Kabushiki Kaisha
InventorsMasaaki Kanashiki, Nobuo Minoura
Life of this patent
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Abstract
The present invention relates to an apparatus by which, in the image display corresponding to a image signal, image signal is processed to adjust the contrast of the picture so as to provide automatically the contrast adjustment most suitable for respective level of image signal, thereby improving the quality of the picture by regulating the level of the image signal according to the information showing the distribution status of the levels of image signals input during a specified period of time.
Claims21
An image signal processing apparatus which processes image signals, comprising:
- (A) level distribution information generating means for receiving an image signal, detecting the level distribution state of image signals received over a predetermined period and generating information indicative of the level distribution state detected;
- and
- (B) level control means for controlling the level of the image signal according to the information generated by said level distribution information generating means so that a dynamic range indicative of the level distribution state of the image signal detected by said level distribution information generating means becomes wider than a predetermined level range.
An image signal processing apparatus to process image signals, comprising:
- (A) conversion means for converting analogue image signals into digital data and output said digital data;
- (B) detection and operation means for detecting and operating the maximum value, the minimum value and the intermediate value of said digital data;
- (C) coefficient calculation means for calculating a first coefficient based on the maximum value, the minimum value and the intermediate value detected and operated by said detection and operation means;
- (D) coefficient generation means for generating a second coefficient;
- (E) coefficient operation means for operating a third coefficient using the first coefficient calculated by said coefficient calculation means and the second coefficient generated by said coefficient generation means;
- and
- (F) level control means for controlling the level of image signals using the third coefficient calculated by said coefficient operation means.
An image signal processing apparatus which processes image signals, comprising:
- (a) conversion means for image signals into digital data and output said digital data;
- (b) detection and operation means for detecting and operating the maximum value, the minimum value and the intermediate value of said digital data and for shifting the level of the intermediate value calculated according to the level of the detected maximum value or the minimum value;
- (c) coefficient calculation means for calculating a first coefficient based on the maximum value, the minimum value and the intermediate value detected and operated by said detection and operation means;
- (d) coefficient generation means for generating a second coefficient;
- (e) coefficient operation means for operating a third coefficient using the first coefficient calculated by said coefficient calculation means and the second coefficient generated by said coefficient generation means;
- and
- (f) level control means for controlling the level of image signals using the third coefficient calculated by said coefficient operation means.
Dependencies are inferred from the claim text.