摘要:
A method for coding spatial and quality enhancement information in scalable video coding using variable length codes. Conventional systems have been capable of using variable length codes only with nonscalable video coding, In the present invention, the coded block pattern for each block of information, significance passes, and refinement passes can all be coded with different types of variable length codes. The present invention also provides for a variable length encoder/decoder that dynamically adapts to the actual symbol probability. The encoder/decoder of the present invention counts the number of times each symbol is coded. Based upon these counts, the encoder/decoder selects how many symbols to group when forming a code word. The encoder also uses these counts to select the specific codeword that should be used.
摘要:
A system and method for improved video encoding and decoding. The present invention addresses issues that arise in the H.264/AVC standard involving “high magnitude coefficients.” According to various embodiments of the present invention, an encoded end of block (EOB) symbol provides information comprising at least one of the maximum magnitude of values in a block, the number of values in the block with a magnitude greater than 1, and a variable length code (VLC) index indicating a VLC to be used in decoding precise magnitudes for non-zero values in the block. By including this information in the EOB symbol, improved coding efficiency is achieved.
摘要:
A method and system for detecting slant edge areas in an image comprising a plurality of pixels, and for preventing zigzagged slant edge artifacts in an image detail enhancement process. Image pixels that belong to a slant image edge are detected and gain suppression factors are determined for the detected pixels. The image is detail enhanced while selectively reducing enhancement of the detected image pixels relative to enhancement of other image pixels based on the gain suppression factors.
摘要:
A system and method for detecting location and luminance transition range of slant image edge in a digital image. The variance value for the pixels inside a window in the image is calculated, based on which a current pixel is classified. If the current pixel is in a non-edge region, no further checking is needed, otherwise binary pattern data is generated from the pixels inside the window. Then it is determined whether the current pixel is a center pixel in a luminance transition range of a slant edge based on the binary pattern data at the current pixel location and its neighboring binary pattern data. If the current pixel is the center pixel in a luminance transition range of a slant edge, then the length of the luminance transition range of the slant edge is determined.
摘要:
An FGS entropy coding method is suitable for the case when the refinement coefficients at the FGS layer have different prediction from its base layer. When temporal prediction is used in FGS layer coding and the refinement coefficients at the FGS layer have different prediction from its base layer, drift problem may be caused if the FGS layer is partially decoded. Such drift problem may significantly affect coding performance. This new FGS entropy coding method that can solve or greatly alleviate such drift effect and therefore improve coding performance. Three different FGS methods can be used: FGS entropy coding based on spatial frequency location; FGS entropy coding for decoder oriented two-loop structure; and FGS entropy coding with block-confined coding pass.
摘要:
An improved system and method for dequantizing progressively quantized signals in scalable image and video coding. A decoder performs simple dequantization, such as normal uniform dequantization, on coded content using a quantization index and a nominal quantization step size to obtain a nominal reconstruction level. The result is then adjusted by adding the reconstruction offset to obtain the final reconstruction value.
摘要:
An image detail enhancement method and apparatus that is suitable for different types of digital images, regardless of their signal frequency range or noise level. The detail enhancement apparatus has multiple filters termed, detail filter bank. A detail filter can be e.g. a high pass filter (HPF) or a band pass filter (BPF). In a detail filter bank, each detail filter has a pass band covering a specific frequency range and can therefore be used to obtain the detail signal in the corresponding frequency range from the original signal. The detail signals from those detail filters can then be processed before added back to the original signal as enhancements. This provides image detail enhancement that is suitable for different types of digital images (regardless of their signal frequency range or noise level).
摘要:
Scalable video coding techniques include encoding blocks by scan position within a coding cycle in decreasing order to increase the probability of the next symbol will be non-zero. When truncating a fine granularity singularity (FGS) slice, instead of removing a constant fraction of every slice, the fraction is a truncation ration that is set to depend on the temporal level of the slice being truncated.
摘要:
A system and method for providing improved FGS identification in scalable video coding. According to the present invention, each FGS enhancement layer is assigned a unique dependency identifier and contains only FGS enhancement information. For subsequent enhancement layers, the base dependency identifier will point to either a base-quality layer or an FGS enhancement layer. Alternatively, two base dependency identifiers can be used. One identifier is used to identify the base quality layer, which does not contain FGS information, that is used for the prediction of coding mode and motion information for a subsequent enhancement layer. The other identifier is used to identify the FGS enhancement layer, which contains only FGS information, that is used for the prediction of sample and/or residual data for a subsequent enhancement layer.
摘要:
A system and method for providing quality scalability in a video stream. A bit stream is provided with a video sequence having a base layer and an enhancement layer. The enhancement layer includes a plurality of enhancement layer blocks, each of which includes a block coefficient. Each layer block coefficient is assigned to one of a plurality of zones, and layer block coefficients assigned to a particular one of the plurality of zones are removed periodically.