摘要:
In a video signal processor (10), a video signal is given to a video input terminal (101) via a coupling capacitor (200). A clamp circuit (104) clamps the video signal input via the video input terminal (101). A format detector section (105) detects a format of the video signal. A controller section (107) changes power supply capability of the clamp circuit (104) according to a detection result of the format detector section (105).
摘要:
This invention provides a data signal extraction apparatus that accurately extracts data from a data signal that is serially transmitted even when phase shift or the like occurs. According to this apparatus, a phase shift amount calculation circuit 13 calculates a phase shift amount S13, then a correction amount calculation circuit 14 calculates a correction amount S14 on the basis of the phase shift amount S13, an extraction interval correction circuit 10 corrects an extraction interval value S9 on the basis of the correction amount, and an extraction pulse generation circuit 11 generates an extraction pulse S11 on the basis of a corrected extraction interval value S10, thereby extracting data from a binary signal S8 on the basis of the extraction pulse.
摘要:
A false contour correcting apparatus is capable of removing a false contour in an image based on a digital image signal while avoiding such a side effect caused by false contour correction where noises negatively effecting the display occur on a screen. Therefore, in the false contour correcting apparatus according, a double bit change detection circuit detects as a double bit change a signal value change which is twice a minimum quantization unit in a digital image signal, and outputs a double bit change detection signal representing the position of the double bit change. A signal correction circuit corrects the double bit change in the digital image signal into two one-bit changes on the basis of the double bit change detection signal. Consequently, a false contour corresponding to a portion where the double bit change exists is removed.
摘要:
In a semiconductor device of the present invention, a clock is not changed instantaneously but it is changed over maximum N+1/M clocks (N: integer not less than 2) by shifting delay cells stepwisely to make the phase state of a previous reference signal and the phase state of a present reference signal coincide with each other, whereby the clock is synchronized with the reference signal with accuracy, and the duty of the output clock is kept constant. According to the semiconductor device of the present invention, it is possible to prevent the duty of the clock from being discontinuous when a signal whose reference signal does not coincide with the clock is inputted and reset is made to a rising edge of this reference signal.
摘要:
In a video signal character converting device, a sampling window signal generator generates a signal for sampling an input video signal “a”. A video scene amplitude discrimination circuit samples the video signal in response to the sampling signal, detects a change in image level either field by field or frame by frame based on an integrated value for every duration of vertical scanning, and outputs a resetting pulse when the change in picture level exceeds a predetermined level. A video scene periodicity discrimination circuit measures a time interval between two successive resetting pulses, and outputs a control signal if the time interval is shorter than a predetermined period. A video scene conversion circuit converts a video scene in response to the control signal. The video signal character detecting device of the present invention determines as to whether or not the input video signal has video images that present an adverse effect mentally and physically to viewers, by observing an image level and periodicity of the video signal in this manner. The device is thus able to output video images by converting them into a harmless level with a process of reducing contrast or blanking, if it determines the video images harmful.
摘要:
Red color saturation is increased and red color with higher purity can be reproduced by composing: a red color detection circuit 1 for detecting a red color signal having higher purity by inputting color differential signals (R-Y) and (B-Y) modulated by color subcarrier, subtracting the absolute value of the (B-Y) signal from the positive polarity component of the (R-Y) signal and removing the negative part of the subtracted signal; Y signal compensation block including: first gain controller 50b for controlling the output signal amplitude of red color detection circuit 1 and a subtracter 50a for subtracting the output signal of first gain controller 50b from a luminance signal Y; an (R-Y) signal compensation block including: second gain controller 51b for controlling the output signal amplitude of red color detection circuit 1 and an adder 51a for adding the output signal of second gain controller 51b and the input (R-Y) signal; and a (B-Y) signal compensation block including: third gain controller 52b for controlling the output signal amplitude of red color detection circuit 1, a polarity inverter 52c for inverting the output signal polarity of third gain controller 52b, a switch circuit 52d for selecting either input signal or output signal of polarity inverter 52c, a polarity discriminater 52e for discriminating the polarity of the input (B-Y) signal and controlling switch circuit 52d and an adder 52e for adding the output signal of switch circuit 52d and the input (B-Y) signal.
摘要:
A black compensation circuit for compensating a luminance signal which is subjected to edge enhancement, comprises: a black-level expanding circuit responsive to a control signal including an edge enhancement component and the luminance signal for performing expansion of a tone of a black portion of the luminance signal and for performing conversion of the luminance signal into a black-level expanded signal in the absence of the control signal; a low-pass filter circuit for low-pass filtering the luminance signal to remove the edge enhancement component; a detection circuit responsive to an output of the low-pass filter circuit for detecting the blackest level for a given interval; and a comparing circuit for comparing the blackest level with a given level to produce the control signal, the black-level expanding circuit stopping the expansion and the conversion in the presence of the control signal. The blackest level does not change with sharpness because after the luminance signal subjected to edge enhancement is passed through the low-pass filter, it is sent to the detection circuit. An input signal of the low-pass filter may be supplied from the black-level expanding circuit.
摘要:
In a gradation corrector used in a television receiver, a clipping circuit is connected to an output of a histogram memory and a clipping level of the clipping circuit is changed in accordance with an output of an S/N detecting circuit. Thereby, when the minimum value is detected, it is possible to prevent a large variation of the value to be detected which may be caused from noises or the like. Also, a circuit for detecting a change in video scene and a recursive filter circuit composed of an adder and a xK circuit (and a two-input/one-output selector circuit are provided on the output side of a clipping circuit and the coefficient value K of the xK circuit (or the selector circuit is controlled in accordance with an output of the video scene change detecting circuit. Thereby, it is possible to make a smooth gradation correction which is not affected by noises or the like (or to make a gradation correction with rapid response which follows a change in video scene.
摘要:
Disclosed is a noise reduction circuit in which a YC-separated luminance signal and a YC-separated chromaticity signal are separately processed for noise reduction. In the noise reduction circuit, delay elements incorporated in a YC separation circuit are also used as delay elements in a contour correction circuit so as to attain the desired purpose of noise reduction in both the luminance signal and the chromaticity signal and also the desired purpose of contour correction. Thus, both the noise reduction and the contour correction can be achieved by the noise reduction circuit which is simple in structure and inexpensive.
摘要:
A driving device for driving an image display system, which sequentially receives input image data corresponding to gradation of each pixel of a display image and outputs a driving voltage signal includes: an operation section for obtaining output image data of which a bit number is smaller than a bit number of the input image data based on input image data of a target pixel to be processed and input image data of a pixel in vicinity of the target pixel; a reference voltage generation section for generating a plurality of reference voltages of different levels; and a reference voltage selection section for selecting one of the plurality of reference voltages. The operation section is configured to obtain output image data of the target pixel so that a difference between the input image data and output image data of the target pixel and a difference between the input image data and output image data of the pixel in vicinity of the target pixel cancel out each other.