摘要:
Provided are a digital video rescaling system, a method of rescaling video images, and a chip comprising a computer executable medium embedded therein computer executable instructions for rescaling video images.
摘要:
A video image processing system is described that generates the interpolated video images with sharp and jaggedness-free edges. A method of video image processing is also described that interpolates video images to generate the video images with sharp and jaggedness-free edges. The video image processing system receives and makes input image data available for further processing; analyzes the local features of the input image data; filters the input image data before performing interpolation process; modifies the phase value adaptive to the local edge distance; rescales the input image data in horizontal interpolation using the modified phase value; and rescales the horizontally interpolated image data in vertical interpolation using modified phase value.
摘要:
A method and apparatus control bit rates used in a moving pictures encoder, such as an MPEG standard encoder. A sequence of moving pictures is divided into segments each of which comprises one or more groups of pictures. A constant overall bit rate is specified for the sequence of pictures, but variable bit rate encoding used within each segment. A difference between the number of bits allocated for encoding the segment and the actual bits used for encoding is determined, and the difference distributed over one or more subsequent segments.
摘要:
Method of compressing a digital image signal in which a first quantization step set, which is unique for a given segment, is determined so that the number of bits needed to encode the quantized data corresponding to this segment is greater than a target value. This first quantization step set then being modified, as a priority, for the blocks of the segment for which the gain, in the course of this modification, on the reduction of the number of bits needed to encode the quantized data corresponding to the segment to which it belongs, is the highest. This modification is carried out, on as many blocks as is necessary for the number of bits of this segment to be less than or equal to the target value. Device to implement this method.
摘要:
A method and system for digital video noise reduction which includes a picture analyser (103) for analysing pictures in a video sequence to determine the amount of moving regions therein, a noise level detector (102) for estimating the noise level (N) in the video sequence, a filtering level estimator (105, 103) for determining a maximum filtering level (L) for each picture based on the amount of moving regions and the estimated noise level (N) and a spatial filter (106) and a temporal filter (107), the temporal filter being coupled to the filter level estimator for controlling the level of filtering of each picture in the sequence in accordance with the maximum filtering level.
摘要:
A method and apparatus for noise level estimation in a digital video signal, the apparatus including a pixel activity detector that produces a mean pixel activity level for each picture in the video signal, a contrast analyzer that produces a contrast activity level for each picture and a noise level calculator that is coupled to the activity detector and contrast analyzer to produce an estimated noise level by offsetting the contrast activity level from accumulated output of the activity detector.
摘要:
A processor for enhancing an input luminance signal including: a means for calculating a chroma edge value associated with the input luminance signal; a means for measuring a luminance gradient associated with the input luminance signal; a peaking filter for processing the input luminance signal; a gain adjustment circuit having a gain function that is adjustable relative to the calculated chroma edge value, the gain adjustment circuit being operable to adjust the magnitude of the output of the peaking filter wherein: in a first range of luminance gradients, the output is an attenuated version of the input; in a second range of luminance gradients the output is directly proportional to the input; in a third range of luminance gradients, the output is inversely proportional to the input; wherein said enhanced luminance signal is the sum of the input and output of the peaking filter.
摘要:
This method and apparatus described herein imposes masking factors to the determined quantization step sizes of macroblocks of a video sequence such that encoding efficiency is increased. A conditional masking method can be used to take advantage of the fact that P-pictures are more important than B-pictures in terms of motion and scene updates as coding noise in such updates are likely propagated by P-pictures. The masking can be applied conditionally to motion/scene update regions of a picture such that coding noise is reduced and therefore bits are saved from less propagation of this noise. Before encoding each macroblock of a picture from an input video sequence, a video encoder with conditional masking determines if the macroblock type belongs to a significant motion or scene update region. A conditional masking factor is then determined for the macroblock based on the determined macroblock type and the picture coding type. The conditional masking factor is combined with a macroblock reference quantization step-size which may be calculated using conventional methods based on bit allocation and bit utilization, and an optional activity masking factor based on activity level of the macroblock and/or its surrounding region to form the final quantization step-size for coding of the macroblock.