IMAGE ENCODING APPARATUS

摘要

Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, the plurality of sub-blocks are scanned and coefficients of each sub-block are scanned using a scan pattern determined according to the intra prediction mode. The quantized coefficients of each subset are scanned in a reverse direction from a last non-zero coefficient according the scan pattern. Furthermore, the apparatus generates reference pixels using available reference pixels when reference pixels do not exist, adaptively filters reference pixels based on the intra prediction mode and size information of the prediction block, and generates the prediction block.

主权项

1. An image encoding apparatus, comprising:
an intra prediction unit configured to generate a prediction block according to an intra prediction mode selected out of a plurality of intra prediction modes; a subtracting unit configured to generate a residual block by calculating a difference between the prediction block and an original block; a transform unit configured to transform the residual block to generate a transform block; a quantization unit configured to quantize the transform block using a quantization step size to generate a quantized transform block; a scanning unit configured to scan the quantized transform block to generate one-dimensional (1D) quantized coefficients; and an entropy coding unit configured to entropy-code the 1D quantized coefficients, wherein, when a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, wherein the plurality of sub-blocks are scanned and coefficients of each sub-block are scanned using a scan pattern, wherein the scan pattern for scanning the plurality of sub-blocks and for scanning the coefficients of each sub-block is determined according to the selected intra prediction mode, wherein the quantized coefficients of each subset are scanned in a reverse direction from a last non-zero coefficient according the scan pattern, and wherein the intra prediction unit includes: a reference pixel generating unit configured to generate reference pixels using available reference pixels of a current block when reference pixels do not exist; a reference pixel filtering unit configured to adaptively filter reference pixels adjacent to the current block based on the selected intra prediction mode and size information of the current block; and a prediction block generating unit configured to generate the prediction block of the current block according to the selected intra prediction mode.