Method and apparatus for encoding and decoding image by using inter color compensation

An image encoding apparatus comprising:

• a predicted block generation unit which generates a predicted block of a current block that is to be encoded in a second color component image, which is one of two or more color component images contained in a received image, by using a reference block of an encoded and restored first color component image of the two or more color component images;
• a first residual block generation unit which generates a first residual block by calculating the difference between the predicted block and the original current block of the second color component image;
• a neighboring pixel prediction unit which predicts neighboring pixels of the current block of the second color component image by using corresponding neighboring pixels of the reference block of the first color component image;
• a predicted residual block generation unit which generates a predicted residual block by using residual neighboring pixels representing the differences between predicted pixels of neighboring pixels of the current block of the second color component image and the original neighboring pixels of the current block, where the predicted residual block is a predicted block of the first residual block;
• and
• a second residual block generation unit which generates a second residual block by calculating the difference between the first residual block and the predicted residual block.

A method of decoding an image, comprising:

• decoding a first color component image which is one of two or more encoded color component images contained in a received bitstream;
• generating a predicted block of a current block that is to be decoded in a second color component image of the two or more encoded color component images by using a reference block of the decoded first color component image;
• predicting neighboring pixels of the current block of the second color component image by using corresponding neighboring pixels of the reference block of the first color component image;
• generating a predicted residual block by using residual neighboring pixels representing the differences between predicted pixels of the neighboring pixels of the current block of the second color component image and previously restored neighboring pixels of the current block, where the predicted residual block corresponds to a predicted block of a first residual block representing the difference between the current block and the predicted block;
• generating the first residual block by combining the predicted residual block and a second residual block which represents the difference between the first residual block and the predicted residual block, where the second residual block is included in the bitstream;
• and
• decoding the current block by combining the first residual block and the predicted block.

An image decoding apparatus comprising:

• a predicted block generation unit which generates a predicted block of a current block that is to be decoded in a second color component image, which is one of two or more encoded color component images contained in a received bitstream, by using a reference block of a decoded first color component image of the two or more encoded color component images;
• a neighboring pixel prediction unit which predicts neighboring pixels of the current block of the second color component image by using corresponding neighboring pixels of the reference block of the first color component image;
• a predicted residual block generation unit which generates a predicted residual block by using residual neighboring pixels representing the differences between predicted pixels of the neighboring pixels of the current block of the second color component image and previously restored neighboring pixels of the current block, where the predicted residual block corresponds to a predicted block of a first residual block representing the difference between the current block and the predicted block;
• a residual block restoration unit which generates the first residual block by combining the predicted residual block and a second residual block which represents the difference between the first residual block and the predicted residual block, where the second residual block is included in the bitstream;
• and
• an addition unit which decodes the current block by combining the first residual block and the predicted block.