Method and apparatus for image encoding/decoding, and recording medium storing bitstream

An image encoding method performed by an image encoding apparatus, the image encoding method comprising:

• determining whether an inter-component prediction mode is applicable to a current chroma block;
• deriving one of the inter-component prediction modes as an intra prediction mode of the current chroma block, based on the inter-component prediction mode being applicable to the current chroma block;
• down-sampling luma samples of a current luma block corresponding to the current chroma block;
• deriving down-sampled neighboring luma samples based on neighboring luma samples of the current luma block;
• deriving prediction parameters for inter-component prediction based on the intra prediction mode;
• deriving prediction samples for the current chroma block based on the down-sampled luma samples and the prediction parameters, and
• encoding image information including information related to whether one of the inter-component prediction modes is applied to the current chroma block and index information indicating one of the inter-component prediction modes,
• wherein the prediction parameters are derived based on the down-sampled neighboring luma samples, and
• wherein whether the inter-component prediction mode is applicable to the current chroma block is determined based on a size of the current chroma block, a partition depth of the current chroma block and a shape of the current chroma block.

A transmitting method for image data, the method comprising:

• obtaining a bitstream of encoded image information, wherein the encoded image information is generated based on determining whether an inter-component prediction mode is applicable to a current chroma block, deriving one of the inter-component prediction modes as an intra prediction mode of the current chroma block, based on the inter-component prediction mode being applicable to the current chroma block, down-sampling luma samples of a current luma block corresponding to the current chroma block, deriving down-sample neighboring luma samples based on neighboring luma samples of the current luma block, deriving prediction parameters for inter-component prediction based on the intra prediction mode, deriving prediction samples for the current chroma block based on the down-sampled luma samples and the prediction parameters, and encoding image information including information related to whether one of the inter-component prediction modes is applied to the current chroma block and index information indicating one of the inter-component prediction modes, and
• transmitting the image data comprising the bitstream, wherein the prediction parameters are derived based on the down-sampled neighboring luma samples, and
• wherein whether the inter-component prediction mode is applicable to the current chroma block is determined based on a size of the current chroma block, a partition depth of the current chroma block and a shape of the current chroma block.