摘要:
A video signal compression apparatus extracts a specific value written in a read only memory at every system clock pulse. The specific value can be varied at every clock pulse. Therefore, for example, only the center cart of a picture can be horizontally compressed A FIFO memory may be used. It is possible to select a mode with a fixed compression ratio or a mode in which a compression ratio varies at every clock pulse. Further, the fixed compression ratio can be set from the outside. Display position or the picture can also be changed.
摘要:
A small scale gain control circuit for controlling gain correction quantity is realized, using the configuration of an inverter, a subtraction circuit, a limiter, and a multiplication circuit. Gain correction quantity is controlled in such a way that in the gradation correcting apparatus a first constant fixes a value beyond which gain correction quantity is zero and a second constant fixes an inclination of the characteristics line.
摘要:
A gradation correcting apparatus, which can be effectively incorporated into various video devices, enables the display of a sub-display within the domain of main-display (i.e. Picture in Picture) and also enables automatic adjustment of each gradation of the display dependent on the characteristics of the respective input signal. By using both a window pulse and a main- and sub-display switching signal, gradation corrections of the displays are carried out such that either no gradation correction is applied to the sub-display or a proper correction is applied according only to the sub-display signal. In this apparatus, the luminance information related to the sub-display and the luminance information related to the main-display excluding that of the sub-display are independently inputted into a signal correction system, thereby allowing individual processing of this information. Moreover, since the signal delay caused by the arithmetic processing can be precisely compensated for by a delay device, the gradation corrections for the main- and sub-displays are exactly executed according to the respective luminance level information, thus realizing an easy-to-see Picture in a Picture.
摘要:
The invention relates to an intensity correction device for automatically adjusting an intensity of an input video signal by detecting luminance characteristics of the input signal, and provide intensity correction with maintaining clear image by reducing magnitude of the correction signal or by not effecting correction when the luminance level of the input luminance signal is concentrated to a certain luminance level. The intensity correction device includes a histogram memory, a look-up table operating circuit, a look-up table, a maximum value detecting circuit, and an inverter and a multiplier, limiter, or a gain control circuit. By this, when a luminance level of the input video signal is concentrated to a certain luminance level, magnitude of the correction signal can be reduced or made zero. Therefore, by detecting the characteristics of the input image, the intensity of the input video signal can be automatically corrected to the optimal image for providing better picture quality.
摘要:
A video signal compression apparatus extracts a specific value written in a read only memory at every system clock pulse. The specific value can be varied at every clock pulse. Therefore, for example, only the center part of a picture can be horizontally compressed. A FIFO memory may be used. It is possible to select a mode with a fixed compression ratio or a mode in which a compression ratio varies at every clock pulse. Further, the fixed compression ratio can be set from the outside. Display position of the picture can also be changed.
摘要:
An apparatus for converting an input video signal to a modified video signal comprises a memory for storing data corresponding to the input video signal, an address signal generating device for reading data from the memory and an interpolating filter for interpolating the data read from the memory to obtain a modified video signal. The data are stored and read from the memory using a clock having a predetermined frequency. However, since the number of addresses being read in one horizontal display varies with the conversion rate of video signals, the length of one horizontal display of the modified video signal is different from that of the input video signal.
摘要:
An outline enhancing device for enhancing an outline of an image formed by a video signal having a rising and falling slope portions and a flat portion includes an enhancing signal producing circuit for producing an enhancing signal having a first, a second, and a third enhancing waveforms which wavelengths are the same as those of three portions of the video signal, respectively. A delay circuit is provided for delaying the video signal to be synchronized with the enhancing signal. A subtracter is further provided for subtracting the enhancing signal from the synchronized video signal such that three enhancing wavesforms are exactly superimposed on the rising slope, the falling slope and the flat portions, respectively, without any interference to the neighboring slopes or portion. As a result of such subtraction, the gradients of the rising and falling slopes are made large while the flat portion is extended. Thus, the outline in the video signal is enhanced without preshoots or overshoots around the outline.
摘要:
A video signal compression apparatus extracts a specific value written in a read only memory at every system clock pulse. The specific value can be varied at every clock pulse. Therefore, for example, only the center part of a picture can be horizontally compressed. A FIFO memory may be used. It is possible to select a mode with a fixed compression ratio or a mode in which a compression ratio varies at every clock pulse. Further, the fixed compression ratio can be set from the outside. Display position of the picture can also be changed.
摘要:
The invention relates to a video signal memory equipment comprising a FIFO memory for storing video data of video signals, and a control unit for controlling writing and reading in the FIFO memory, wherein the control unit receives a horizontal synchronizing signal of video signal in video data writing action, writes a specified number of video data from the beginning of video data of brightness signals of the horizontal scanning period sequentially into the FIFO memory, and reads out the specified number of video data upon every input of horizontal synchronizing signal, in video data reading action, in the written sequence as video data of that horizontal scanning period, thereby storing and producing the video data of video signals, whereby video data of each horizontal scanning period of video signals are continuously written into the FIFO memory by every specified number of pieces from the beginning, and are read out by every specified number of pieces upon every input of horizontal synchronizing signal, and hence the video data of video signals can be read out by dividing in every horizontal scanning period, and therefore the address generating device for dividing the data in every horizontal scanning period is not needed in this video signal memory equipment.
摘要:
A level of an input luminance signal for a pixel is compared with step values which change stepwise in level in a predetermined range of level, and distribution of the levels of the input luminance signal in the predetermined range of level is represented by a cumulative histogram. Subsequently, a histogram value is derived from the outline of the cumulative histogram, and a compensation value is produced on the basis of the histogram value, and the compensation value is added to the input luminance signal, and hence a compensated luminance signal is output to control the luminance of a video image.