Abstract: A contrast control apparatus includes a statistic distribution unit and a characteristic judging unit. The statistic distribution unit receives an image data to have a brightness histogram distribution in statistic. The brightness histogram distribution has a plurality of statistic nodes, respectively corresponding to a plurality of gray levels in statistic. The characteristic judging unit at least receives the brightness histogram distribution to determine a brightness adjusting signal for the image data, so as to proportionally adjust a brightness of a display light source. In addition, the characteristic judging unit also outputs a contrast curve, and the contrast curve represents a plurality of adjusted nodes, respectively corresponding to the statistic nodes. As a result, the brightness of the statistic nodes is changed.

Abstract: A method for dithering image data is provided. The method is suitable for representing A-bit grayscale values with a B-bit resolution, where A and B are positive integers and A>B. The main steps of the method include calculating 2A target grayscale values with decimals within an interval from 0 to (2B?1)*2A?B, and then representing the target grayscale values with the decimals through 2-dimensional dithering or 3-dimensional dithering.

Abstract: An apparatus for image upscaling and the method thereof. The apparatus includes an ADC and a downscaling circuit. The ADC samples and digitizes the signal of an original image at a sampling rate of an integer multiple of the resolution of the original image. The sampled and digitalized result is assembled and output as an oversampled image. The downscaling circuit downscales the oversampled image into a target image by interpolation. The resolution of the oversampled image is greater than or equal to that of the target image, and the resolution of the target image is greater than that of the original image.

Abstract: The present invention discloses a dynamic period detecting method and detector, which utilizes a zero-crossing detecting method to detect a rough estimated period and then uses a weighting-average filtering method to eliminate noises to obtain an accurate period P. Since the average number for generating weight in the weighting-average filtering method is dynamically adjusted according to the period variation, the detecting method can detect the period correctly and fast, and save a lot of storage space and computation time.

Abstract: A real time sensor for signal periods includes a zero crossing sensor for sensing a period of a signal and a noise evaluation circuit. If the noise of the signal is smaller than a predetermined value, the output of the zero crossing sensor is averaged over a plurality of zero crossings to obtain the signal period. The zero crossing sensor uses the average voltage level of the sampled signal preceding the currently sampled signal as an assumed DC bias level, which is subtracted from the sampled voltage values to determine the points at which the sampled signal crosses an axis in order to measure the period of the signal, and the noise evaluation circuit operates by comparing the peak-to-peak value of the currently sampled signal with a reference peak-to-peak value.