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US 12,756,818 B2Granted
Inter-image component prediction method, and image encoding and decoding method and device using same
AssigneeDolby International AB
InventorsJae Gon Kim, Do Hyeon Park, Yong Uk Yoon, Ji Hoon Do
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Abstract
An image encoding and decoding method comprises the steps of: determining an inter-component prediction mode of a chrominance component block on the basis of an inter-component prediction mode list and predetermined index information; determining a reference sample for inter-component prediction of the chrominance component block on the basis of the determined inter-component prediction mode; deriving the parameters of a linear prediction model by using the reference sample; and performing inter-component prediction for the chrominance component block by using the parameters of the linear prediction model.
Claims20
An image decoding method, comprising:
- determining an inter-component prediction mode of a chroma component block based on an inter-component prediction mode list and predetermined index information, wherein the inter-component prediction mode list is configured with k inter-component prediction modes;
- downsampling reference samples for inter-component prediction of the chroma component block based on the determined inter-component prediction mode, the reference samples belonging to at least one of a left neighboring block or a top neighboring block of a luma component block corresponding to the chroma component block;
- classifying the downsampled reference samples into a first group and a second group, wherein the first group represents a minimum value group of first downsampled reference samples having relatively small values among the downsampled reference samples and the second group represents a maximum value group of second downsampled reference samples having relatively large values among the downsampled reference samples;
- obtaining a first average value between the first downsampled reference samples in the first group and a second average value between the second downsampled reference samples in the second group;
- calculating a difference between the first average value and the second average value;
- deriving a parameter of a linear prediction model based on the difference between the first average value of the first group and the second average value of the second group;
- and
- performing the inter-component prediction on the chroma component block based on the parameter of the linear prediction model,
- wherein a filter for the downsampling is variably determined based on whether a top boundary of the luma component block is on a top boundary of a coding tree unit (CTU) to which the luma component block belongs.
6 more elements
An image encoding method, comprising:
- determining an inter-component prediction mode of a chroma component block from an inter-component prediction mode list including k inter-component prediction modes;
- downsampling reference samples for inter-component prediction of the chroma component block based on the determined inter-component prediction mode, the reference samples belonging to at least one of a left neighboring block or a top neighboring block of a luma component block corresponding to the chroma component block;
- classifying the downsampled reference samples into a first group and a second group, wherein the first group represents a minimum value group of first downsampled reference samples having relatively small values among the downsampled reference samples and the second group represents a maximum value group of second downsampled reference samples having relatively large values among the downsampled reference samples;
- obtaining a first average value between the first downsampled reference samples in the first group and a second average value between the second downsampled reference samples in the second group;
- calculating a difference between the first average value and the second average value;
- deriving a parameter of a linear prediction model based on the difference between the first average value of the first group and the second average value of the second group;
- and
- performing the inter-component prediction on the chroma component block based on the parameter of the linear prediction model,
- wherein a filter for the downsampling is variably determined based on whether a top boundary of the luma component block is on a top boundary of a coding tree unit (CTU) to which the luma component block belongs.
6 more elements
An encoder apparatus configured to:
- determine an inter-component prediction mode of a chroma component block from an inter-component prediction mode list including k inter-component prediction modes;
- downsample reference samples for inter-component prediction of the chroma component block based on the determined inter-component prediction mode, the reference samples belonging to at least one of a left neighboring block or a top neighboring block of a luma component block corresponding to the chroma component block;
- classify the downsampled reference samples into a first group and a second group, wherein the first group represents a minimum value group of first downsampled reference samples having relatively small values among the downsampled reference samples and the second group represents a maximum value group of second downsampled reference samples having relatively large values among the downsampled reference samples;
- obtain a first average value between the first downsampled reference samples in the first group and a second average value between the second downsampled reference samples in the second group;
- calculate a difference between the first average value and the second average value;
- derive a parameter of a linear prediction model based on the difference between the first average value of the first group and the second average value of the second group;
- and
- perform the inter-component prediction on the chroma component block based on the parameter of the linear prediction model,
- wherein a filter for the downsampling is variably determined based on whether a top boundary of the luma component block is on a top boundary of a coding tree unit (CTU) to which the luma component block belongs.
6 more elements
Dependencies are inferred from the claim text.