摘要:
An image encoding method for encoding an image in an image encoding apparatus. The encoding method includes: performing, in a quantization unit in the image encoding apparatus, quantization on a chroma component of transform coefficients using a chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation that adds a weight parameter; encoding, in an encoding unit in the image encoding apparatus, a chroma component of quantized coefficients and generating a bit stream; and transferring the bit stream and the weight parameter.
摘要:
An image decoding method for decoding a bit stream in an image decoding apparatus. The decoding process includes receiving the bit stream and a chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation; decoding, in a decoding unit in the image decoding apparatus, the bit stream and generating a chroma component of quantized coefficients; and performing, in a dequantization unit in the image decoding apparatus, dequantization on the chroma component of quantized coefficients using the chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation.
摘要:
An image information decoding method for decoding compressed image information in an image decoding apparatus, which has been coded via a process including dividing an input image signal into blocks, performing an orthogonal transform on the blocks on a block-by-block basis, and quantizing resultant orthogonal transform coefficients. The decoding process includes performing, in a dequantization unit in the image decoding apparatus, dequantization such that a quantization parameter is weighted by an addition operation that adds the weight by addition, and the dequantization is performed on each chroma and luma component of the quantized coefficients using quantization step sizes, said luma component being weighted by the quantization parameter; and performing, in a transform unit in the image decoding apparatus, an inverse orthogonal transform.
摘要:
An image information decoding method for decoding compressed image information which has been coded via a process including dividing an input image signal into blocks, performing an orthogonal transform on the blocks on a block-by-block basis, and quantizing resultant orthogonal transform coefficients. The decoding process includes performing dequantization such that a quantization parameter is weighted by an addition operation, and the dequantization is performed on each chroma components of the quantized coefficients using said weighted quantization parameter, and performing an inverse orthogonal transform.
摘要:
A packetizing method for packetizing a bit stream in a packetizing apparatus. The packetizing method includes encoding, in an encoding unit in the multiplexing apparatus, a chroma component of image data using a chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation that adds a weight parameter and generating the bit stream. The method further includes packetizing, in a packetizing unit in the packetizing apparatus, the bit stream and generating a packetized stream.
摘要:
An image encoding method for encoding an image in an image encoding apparatus. The encoding method includes: performing, in a quantization unit in the image encoding apparatus, quantization on a chroma component of transform coefficients using a chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation that adds a weight parameter; encoding, in an encoding unit in the image encoding apparatus, a chroma component of quantized coefficients and generating a bit stream; and transferring the bit stream and the weight parameter.
摘要:
An image information decoding method for decoding a bit stream in an image decoding apparatus. The decoding process includes decoding, in a decoding unit in the image decoding apparatus, the bit stream and generating a chroma component of quantized coefficients; and performing, in a dequantization unit in the image decoding apparatus, dequantization on the chroma component of quantized coefficients using a chroma quantization parameter calculated on the basis of a luma quantization parameter weighted by an addition operation.
摘要:
An image information decoding method for decoding compressed image information which has been coded via a process including dividing an input image signal into blocks, performing an orthogonal transform on the blocks on a block-by-block basis, and quantizing resultant orthogonal transform coefficients. The decoding process includes performing dequantization such that a quantization parameter is weighted by an addition operation, and the dequantization is performed on each chroma components of the quantized coefficients using said weighted quantization parameter, and performing an inverse orthogonal transform.
摘要:
An image information coding apparatus codes an input image signal in a manner optimized on the basis of the visual characteristics. In quantization, an input image signal is divided into blocks, an orthogonal transform is performed on a block-by-block basis, and resultant orthogonal transform coefficients are quantized. A quantizer includes a weighter for, in the quantization, performing weighting on each component of the orthogonal transform coefficients by means of an addition operation on a parameter specifying one of elements of a series of numbers arranged in accordance with a predetermined rule in correspondence with quantization step sizes.
摘要:
The invention provides an image information conversion apparatus and method by which picture quality deterioration caused by conversion from inputted MPEG2 image compression information into MPEG4 image compression information to be outputted is prevented. When an I picture of an MPEG2 bit stream is to be converted into a P-VOP of an MPEG4 bit stream based on an estimated value of the complexity for each VOP, a scene change detection section detects whether or not the I picture includes a scene change. If a scene change is detected by the scene change detection section, then a GOV structure determination section determines that conversion of the I picture of the MPEG2 bit stream into a P-VOP of an MPEG4 bit stream should not be performed.