摘要:
A multiplexing method for multiplexing a bit stream in a multiplexing apparatus. The 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 multiplexing, in an multiplexing unit in the multiplexing apparatus, the bit stream and generating a system stream.
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 processing apparatus is provided that can define the change amount of a quantizing parameter by suitably reflecting the complexity of image data in the case, when the quantizing parameter is increased a predetermined unit amount, the coarseness the image data of motion picture is quantized becomes r times. An activity computing circuit generates an activity Nactj serving as a complexity of the image data. A ΔQ computing circuit defines a corresponding relationship between activity Nactj and change amount data ΔQ such that the change amount data ΔQ of quantizing parameter increases 1 as the activity Nactj becomes 1.12 times, to thereby acquire change amount data ΔQ corresponding to the activity Nactj generated by the activity computing circuit.
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:
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.
摘要:
A multiplexing method for multiplexing a bit stream in a multiplexing apparatus. The 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 multiplexing, in an multiplexing unit in the multiplexing apparatus, the bit stream and generating a system stream.
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 process 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; and encoding, in an encoding unit in the image encoding apparatus, a chroma component of quantized coefficients.
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 data converting apparatus comprising an MPEG2-image data decoding section 19, a scan-converting section 20, an MPEG4-image encoding section 21, and a picture-type determining section 18. The MPEG2-image data decoding section 19 decodes input MPEG2-image compressed data in both the vertical direction and the horizontal direction by using only lower, fourth-order coefficients. The scan-converting section 20 converts interlaced-scan pixel data to sequential-scan pixel data. The MPEG4-image encoding section 21 generates MPEG4-image compressed data from the sequential-scan pixel signals. The sections 19, 20 and 21 are connected in series. The picture-type determining section 18 is connected to the input of the MPEG2-image data decoding section 19. The section 18 determines the picture type of each frame data contained in the interlaced-scan MPEG4-picture compressed data, outputs only the frame data about I/P pictures, discards the frame data about B pictures, thereby converting the frame rate.