34results about How to "Improve encoding and compression efficiency" patented technology

The invention relates to an intra-frame prediction method, which increase the intra-frame prediction compression efficiency and comprises the following steps: (1) a brightness intra-frame prediction processing unit and a chroma intra-frame prediction processing unit are selected according to the image coding (decoding) frame size; (2) the sizes and the prediction modes of a brightness intra-frame prediction subblock and a chroma intra-frame prediction subblock are selected respectively; (3) the intra-frame prediction is performed according the selected sizes and the prediction modes of the brightness intra-frame prediction subblock and the chroma intra-frame prediction subblock to obtain an intra-frame prediction sampling value and a residual error of the intra-frame prediction subblocks; and (4) the coding mode of the intra-frame prediction subblocks, the brightness intra-frame prediction mode as well as the chroma intra-frame prediction mode and the residual error are coded respectively and then are sent to a code stream. The classification of the intra-frame prediction method is mainly aimed at the circumstances that the sizes of the intra-frame prediction subblocks are 4*8, 8*4, 8*16 and 16*8, and five optional prediction modes are matched, so that 3 percent to 5 percent of code stream bandwidth is saved under the condition that the image quality is identical, and the image encoding compression efficiency is increased; and the effect of simplifying the computational complexity can be also achieved due to the selection of partial prediction modes.

The invention discloses an image brightness compensation method for image coding, belongs to the field of image processing, and solves the problems of complexity, low speed and low compression efficiency of the conventional algorithm for performing brightness compensation for multi-viewpoint video coded images. The image brightness compensation method comprises the following steps: determining brightness difference between a current block P0 and a reference block PS by comparing the brightness difference between a current block template X0 and a reference block template XS, thereby realizing the brightness compensation for the current block; and utilizing a series of solved candidate weight matrixes B alpha, solving the optimal Bj and assigning the optimal Bj to weight matrixes B of the reference block PS, thereby solving the brightness difference between the current block template X0 and the reference block template XS according to B(X0T-XST), which serves as the brightness difference between the current block P0 and the reference block PS for brightness compensation.

The embodiment of the invention relates to a method and a device for scaling motion vectors, and a method and a system for coding/decoding. The method for scaling motion vector comprises that: according to the amount of coordinate offset between a bottom field and a top field of an interlaced scanned image, coordinate transformation is performed on a first motion vector so as to obtain a second motion vector; the second motion vector is scaled so as to obtain a third motion vector; and according to the amount of coordinate offset, coordinate inverse transformation is performed to the third motion vector so as to obtain a fourth motion vector. The embodiment of the invention performs half-pixel compensation or coordinate transformation on the motion vectors before and after being scaled according to the offset of a top-field image and a bottom-field image in spatial positions, transforms a coordinate into a coordinate system reflecting the actual position relation of the images, and then scales the motion vector, thereby having the advantages of according with motion models better, guaranteeing the accuracy of scaling the motion vectors, raising the precision of predicting the motion vectors and improving the efficiency of coding and compressing field images.

The method comprises: dividing video data in each channel collected by multi video cameras into multi viewpoint groups in term of their adjacent location in the collection; each viewpoint group has identical numbers of viewpoints; in each viewpoint group, using the predictive coding relating between the viewpoints; each viewpoint uses same coding approach.

The invention discloses a panorama video octagon sampling method and apparatus. The panorama video octagon sampling method includes the steps: according to a spatial definition requirement, utilizing latitude lines to divide a spherical surface into N annular curved surfaces Oi, wherein i=0, 1, ..., N-1 and N=8K, and K is an integer; utilizing longitudes to divide the annular curved surface Oi into Ti areas, wherein one of the longitudes is a 0DEG longitude; successively marking the obtained areas as Ai, j, and j=0, 1, ..., Ti-1; calculating the average value of the obtained light in every area Ai, j on the spherical surface, and taking the average value as the sampling value Si, j of a sampling point corresponding to the area; and according to the corresponding rules, arranging the sampling values into a 14K*6K matrix. The panorama video octagon sampling method and apparatus enable distribution of the sampling points to satisfy the situation that the sampling points around the equator are more and the sampling points at two poles are very few, thus avoiding redundancy of the sampling structure so as to reduce the number of the sampling points when achieving the same spatial definition.

The invention discloses a coding method of an intra-frame division mark. The coding method is used for solving the technical problem that an existing coding method is low in compressed coding efficiency. The coding method conducts a line controller unit (LCU) address with 0 depth and 0 coding division mark or address difference, and difference in coding adjacent image division manner with 1 depth, effectively reduces the number of depth 0 and 1 division mark coding bits, and improves compressed coding efficiency.

The invention discloses a panoramic video hexagonal sampling method and apparatus. The method comprises the following steps: dividing a spherical surface into N=6 annular curved surfaces by using latitude lines with equal intervals, making the annular curved surfaces as Oi in sequence, i = 0, and 1 ,... N-1, observing from the angle of the centre of sphere, and arranging the Oi from top to bottom; uniformly dividing the annular curved surface Oi into Ti areas by using meridians with equal intervals; calculating an average value of light within each area on the spherical surface to serve as a sampling value of a sampling point corresponding to the area; and arranging the sampling values in a matrix. By adoption of the sampling method, the redundancy of the sampling structure is avoided, and under the condition of realizing the same spatial resolution, the number of the sampling points is reduced, and the data size after sampling is reduced.

The application discloses an image coding method and device. The method comprises: determining a coded area of a current frame; determining a search area in the coded area; searching for a prediction block matching a block to be coded of the current frame in the search area; and utilizing the prediction block to code the block to be coded. The image coding method and device can improve image coding efficiency.