Abstract: A method for controlling sample adaptive offset (SAO) filtering includes: generating a first SAO decision for pixels in a first partial region of a first frame based at least partly on a cost function that uses a first weighting parameter; and generating a second SAO decision for pixels in a second partial region of the first frame based at least partly on the cost function that uses a second weighting parameter. The second partial region is different from the first partial region, and the second weighting parameter is different from the first weighting parameter.

Abstract: An image compression method includes at least the following steps: receiving a plurality of pixels of a frame, wherein pixel data of each pixel has a plurality of color channel data corresponding to a plurality of different color channels, respectively; encoding the pixel data of each pixel and generating bit-streams corresponding to the plurality of color channel data of the pixel, wherein the bit-streams corresponding to the plurality of color channel data of the pixel are separated; packing bit-streams of a same color channel data of different pixels into color channel bit-stream segments, wherein each of the bit-stream segments has a same predetermined size; and concatenating color channel bit-stream segments of the different color channels into a final bit-stream. Alternatively, color channel bit-stream segments of the same pixel are concatenated into a concatenated bit-stream portion, and concatenated bit-stream portions of different pixels are concatenated into a final bit-stream.

Abstract: An image compression method has at least the following steps: receiving source pixel data of a plurality of blocks of a frame; when a lossless compression mode is enabled for the frame, bypassing a source quantization operation and applying a lossless compression kernel to source pixel data of each of the blocks; and when a lossy compression mode is enabled for the frame, applying the source quantization operation to the source pixel data of each of the blocks to generate input pixel data of each of the blocks, and applying the lossless compression kernel to the input pixel data of each of the blocks. For example, the source quantization operation employs an adaptive quantization parameter for each of the blocks such that a size of compressed data of the frame generated under the lossy compression mode does not exceed a bit budget.

Abstract: Methods for determining reference type of each image unit and adjusting the corresponding lambda table of the reference type are disclosed. Embodiments according to the invention are used to improve the quality of video compression or reduce the requirement of memory buffer, memory power or computation power. The reference type is determined based on the encoder system information or image unit information. The frame/slice type structure of a video sequence is adjusted according to the image unit information of encoded frames or together with input frames. By fine-tuning the mode decision process, the coding efficiency can be improved. The mode decision process is modified by adaptively adjusting the lambda table. The lambda table is adaptively determined according to the conventional image unit type (such as Intra coded, predicted or bi-directional predicted type) and the reference type determined.

Abstract: A block prediction search method includes at least following steps: utilizing a data buffer to store bit-depth reduced sample values of a plurality of samples in a first pixel line; detecting occurrence of an edge in the first pixel line according to restored sample values derived from stored sample values in the data buffer; and determining a block prediction vector for a pixel group in a second pixel line different from the first pixel line, wherein the block prediction vector is determined based at least partly on a last edge count value indicative of a number of samples in the first pixel line that have gone by since the edge occurs.

Abstract: A compression method with block prediction includes at least following steps: utilizing a vector buffer to store a final vector information set of at least one pixel group at a same time, wherein each pixel line of an image is composed of a plurality of pixel groups, and a maximum number of the at least one pixel group having the final vector information set simultaneously stored in the vector buffer is smaller than a number of the pixel groups of each pixel line; and when encoding a first pixel group in a first pixel line, obtaining a final vector information of the first pixel group from the vector buffer, and encoding the first pixel group with the obtained final vector information set of the first pixel group, wherein the final vector information set of the first pixel group stored in the vector buffer is derived from performing block prediction search upon a second pixel line.

Abstract: A keyboard equipped with light emitting structure comprises a plurality of keycap portions and a light guide command circuit board which includes an upper light guide plate, a lower light guide plate and a middle plate located between the upper and lower light guide plates. The upper and lower light guide plates have respectively an upper trigger portion and a lower trigger portion at one side facing the middle plate. The middle plate has a hollow zone corresponding to the upper and lower trigger portions, a plurality of coupling portions corresponding to the keycap portion and a plurality of apertures. The upper light guide plate also has an upper mask layer at one side facing the keycap portion and having a transparent zone. The command circuit board receives light from a light emitting unit and transmits the light to illuminate the keycap portion through the transparent zone.

Abstract: An intra prediction method includes at least the following steps: performing a distortion estimation to evaluate a distortion value of a specific block under an intra prediction mode and a transform unit size; using the evaluated distortion value to set a distortion value of the specific block under a first block configuration, the intra prediction mode and the transform unit size; and using the evaluated distortion value to set a distortion value of the specific block under a second block configuration, the intra prediction mode, and the transform unit size. The first block configuration represents a first block size, and the second block configuration represents a second block size different from the first block size.

Abstract: A method for transform processing in video coding is disclosed. Embodiments according to the present invention reduce the computational complexity of determining transform size for a processing block corresponding to a prediction block or a coding block. The transform size determination is based on encoder information or external information without comparing costs associated with different transform sizes. The encoder information can be the size of the processing block or the prediction information. The external information may correspond to the system bandwidth, the network bandwidth, the system power, the remaining energy of the battery in a mobile device, the timing budget related to performing transform for a given transform size. In another embodiment, the transform for each prediction block is performed only during cost evaluation or only during video data reconstruction.

Abstract: One exemplary video encoding method has the following steps: determining a size of a parallel motion estimation region according to encoding related information; and encoding a plurality of pixels by at least performing motion estimation based on the size of the parallel motion estimation region. One exemplary video decoding method has the following steps: decoding a video parameter stream to obtain a decoded size of a parallel motion estimation region; checking validity of the decoded size of the parallel motion estimation region, and accordingly generating a checking result; when the checking result indicates that the decoded size of the parallel motion estimation region is invalid, entering an error handling process to decide a size of the parallel motion estimation; and decoding a plurality of pixels by at least performing motion estimation based on the decided size of the parallel motion estimation region.

Abstract: A method and apparatus for a multiple-channel image/video coding system are disclosed. A residue generation process is applied to the image/video data to generate residue data. A set of integer operations is applied to the residue data across the input channels to generate residue transformed data having multiple output channels. In one embodiment, the residue transformed data associated with a first output channel is related to the difference between a first residue data associated with a first input channel and a second residue data associated with a second input channel. In another embodiment, the residue transformed data associated with a second output channel is related to the second difference between a threshold and a third residue data associated with a third input channel, and wherein the threshold corresponds to the first truncated or rounded average of the first residue data and the second residue data.

Abstract: An image encoding method includes at least following steps: receiving a plurality of target pixels within a frame, wherein pixel data of each target pixel has at least one color channel data corresponding to at least one color channel; determining a bit budget of the target pixels; and performing bit-plane scanning coding upon selected pixels according to the bit budget and a scanning order, and accordingly generating encoded pixel data of the selected pixels as encoded data of the target pixels, wherein the selected pixels are derived from the target pixels, and the bit-plane scanning coding extracts partial bits of pixel data of each selected pixel as encoded pixel data of the selected pixel. In addition, a corresponding image decoding method is provided.

Abstract: An image encoding method with rate control includes at least the following steps: defining a plurality of candidate bit budgets corresponding to different pre-defined maximum encoded bit lengths for one coding unit respectively; when encoding pixel data of a plurality of pixels within a current coding unit of an access unit of a frame, determining a target bit budget selected from the candidate bit budgets and allocating the target bit budget to the current coding unit; and outputting encoded pixel data of the pixels within the current coding unit that is generated from the encoder, wherein a bit length of the encoded pixel data is smaller than or equal to the target bit budget.

Abstract: A method and apparatus of image data compression and decompression are disclosed. According to an embodiment of the present invention, the compression method partitions the image data into access units and encodes each access unit into a bitstream according to a target bit budget. Each access unit is encoded using first data compression to generate a first bitstream and the residual data is further encoded using second data compression to generate a second bitstream if the first bitstream is smaller than the target bit budget. In one example, the second data compression comprises bit plane coding applied to bit plane-ordered data, wherein the bit plane-ordered data is generated by scanning from a most significant bit to a least significant bit of the residual data in a bit plane-wise order. The decompression method comprises steps to recover reconstructed data from the first and second bitstreams.

Abstract: A method and apparatus for processing transform coefficients for a video coder or encoder is disclosed in the present invention. Embodiments according to the present invention reduce the storage requirement for sign bit hiding (SBH), improve the parallelism of SBH processing or simplify parity checking. Partial quantized transform coefficients (QTCs) of a transform block may be processed before all QTCs of the transform block are received. Zero and non-zero QTCs of a scan block may be processed concurrently and the QTCs of multiple scan blocks in a transform block may also be processed concurrently when computing cost function for SBH compensation. The range for searching for a value-modification QTC may be less than the scan block to be processed. Parity checking on QTCs may be based on least significant bits (LSBs) of all QTCs or all non-zero QTCs of a scan block.

Abstract: An image compression method includes at least the following steps: receiving a plurality of pixels of a frame, wherein pixel data of each pixel has a plurality of color channel data corresponding to a plurality of different color channels, respectively; encoding the pixel data of each pixel and generating bit-streams corresponding to the plurality of color channel data of the pixel, wherein the bit-streams corresponding to the plurality of color channel data of the pixel are separated; packing bit-streams of a same color channel data of different pixels into color channel bit-stream segments, wherein each of the bit-stream segments has a same predetermined size; and concatenating color channel bit-stream segments of the different color channels into a final bit-stream. Alternatively, color channel bit-stream segments of the same pixel are concatenated into a concatenated bit-stream portion, and concatenated bit-stream portions of different pixels are concatenated into a final bit-stream.

Abstract: An image compression method has at least the following steps: receiving source pixel data of a plurality of blocks of a frame; when a lossless compression mode is enabled for the frame, bypassing a source quantization operation and applying a lossless compression kernel to source pixel data of each of the blocks; and when a lossy compression mode is enabled for the frame, applying the source quantization operation to the source pixel data of each of the blocks to generate input pixel data of each of the blocks, and applying the lossless compression kernel to the input pixel data of each of the blocks. For example, the source quantization operation employs an adaptive quantization parameter for each of the blocks such that a size of compressed data of the frame generated under the lossy compression mode does not exceed a bit budget.

Abstract: A method and apparatus of image data compression and decompression are disclosed. According to an embodiment of the present invention, the compression method partitions the image data into access units and encodes each access unit into a bitstream according to a target bit budget. Each access unit is encoded using first data compression to generate a first bitstream and the residual data is further encoded using second data compression to generate a second bitstream if the first bitstream is smaller than the target bit budget. In one example, the second data compression comprises bit plane coding applied to bit plane-ordered data, wherein the bit plane-ordered data is generated by scanning from a most significant bit to a least significant bit of the residual data in a bit plane-wise order. The decompression method comprises steps to recover reconstructed data from the first and second bitstreams.

Abstract: A method and apparatus for encoding of video data incorporating loop filtering are disclosed. The method and apparatus according to an embodiment of the present invention determines an initial loop filter level for a frame of the video data according to quality setting of the frame. The information associated with the initial loop filter level is incorporated in the bitstream corresponding to compressed video data. The loop filtering is applied to a macroblock without the need to wait for the whole frame reconstruction to complete. In another embodiment according to the present invention, the initial loop filter level may be refined according to stability associated with the frame. In yet another embodiment according to the present invention, the method may include determining whether segment mode is on or off and determining a frame-level or segment-level initial loop filter level accordingly.

Abstract: A video coding system and circuit emphasizing visual perception are presented, which mainly include a video coding module and a video analysis module. A video frame is respectively input into the video coding module and the video analysis module. The video coding module performs a coding process on the input video frame, the video analysis module analyzes the input video frame to generate a quantization parameter adjustment value, and then the video coding module adjusts each coding parameter with the quantization parameter adjustment value. In this manner, a more efficient compression can be performed on the video frame, and the compressed video frame still maintains good image quality.