| 摘要 |
An image encoding method, decoding method and corresponding device, and intraframe pixel prediction method. The image encoding method comprises: a step of pixel segmentation, segmenting pixels in an image frame; a step of pixel value prediction, respectively performing a pixel value prediction process to obtain a first prediction value for each of pixels in a current block to be encoded; a step of residual calculation, calculating a residual for each of the pixels in the current block to be encoded; a step of discrete cosine transform, quantization and entropy encoding, performing discrete cosine transform, quantization and entropy encoding with respect to a residual block corresponding to the current block to be encoded obtained in the residual calculation step, wherein the quantized residual block is used in a pixel value reconstruction step at an encoding end, and the entropy encoded residual block is sent to a decoding end; and a pixel value reconstruction step, reconstructing a pixel value of the previously-encoded pixel, wherein the reconstructed pixel value is used in the pixel value prediction step. The residual calculation step comprises: calculating a first residual with respect to a pixel on the basis of the first prediction value of the pixel predicted in the pixel value prediction step and an actual value of the pixel; determining whether the first residual of the pixel is a normal residual or an abnormal residual; correcting the abnormal residual if the first residual of the pixel is an abnormal residual, the correction including recording a position where the abnormal residual of the pixel has occurred; re-predicting the pixel to obtain a second prediction value and a corresponding second residual, and recording the re-prediction information, such that the pixel value reconstruction step of the encoding end and the decoding end can both reconstruct and decode the pixel value of the pixel on the basis of the position where the abnormal residual of the pixel has occurred and the re-prediction information, wherein the normal residual block of the current block is formed by the residual of the pixel of the current block to be encoded after undergoing the abnormal residual correction, and is provided for further processing in the discrete cosine transform, quantization and entropy encoding step; separately encoding the position where the abnormal residual of the pixel has occurred and the re-prediction information, wherein the encoding process is lossless, and the encoded pixel position and the re-prediction information are used in the pixel value reconstruction step and sent to the decoding end. Pixels can be re-arranged before segmentation, thereby avoiding error diffusion. In the pixel value prediction process, a prediction algorithm can be predicted first, and the pixel value is then predicted according to the determined prediction algorithm. By classifying the pixel residual into the normal residual and the abnormal residual, as well as by performing a re-prediction of the pixel of the abnormal residual, the accuracy of image encoding/decoding can be improved. |
