Method and apparatus for image encoding and image decoding
AssigneeSamsung Electronics Co., Ltd.
InventorsYu-mi SOHN, Woo-jin HAN
Life of this patent
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Abstract
Provided are a method and apparatus for image encoding which improves encoding efficiency in accordance with image characteristics by performing prediction in lines and performing a one-dimensional transformation in lines on an input image, and a method and apparatus for image decoding. Encoding efficiency of an image may be improved by generating a prediction sub residual block using neighboring residues and performing a one-dimensional discrete cosine transformation (DCT) on a difference residual block which is a difference between an original sub residual block and the prediction sub residual block.
Claims6
A method of image encoding, the method comprising:
- dividing an input image into a plurality of image blocks;
- generating prediction values of pixels of each image block in horizontal or vertical lines;
- generating residues that are differences between original values and the prediction values of the pixels, in lines;
- and
- performing a one-dimensional discrete cosine transformation (DCT) on the residues in lines.
An apparatus for image encoding, the apparatus comprising:
- a prediction unit which divides an input image into a plurality of image blocks and generates prediction values of pixels of each image block in horizontal or vertical pixel lines;
- a subtraction unit which generates residues that are differences between original values and the prediction values of the pixels, in lines;
- and
- a transformation unit which performs a one-dimensional discrete cosine transformation (DCT) on the residues in lines.
A method of image decoding, the method comprising:
- restoring residues that are differences between prediction values and original values of horizontal or vertical pixel lines and are included in a received bitstream;
- predicting pixel values of each pixel line to be decoded by using pixel values of a previous pixel line decoded in a predetermined order;
- and
- decoding pixels of the pixel lines by adding the predicted pixel values of the pixel lines and the restored residues.
An apparatus for image decoding, the apparatus comprising:
- a prediction unit which predicts pixel values of horizontal or vertical pixel lines to be decoded by using previous pixel lines in vertical or horizontal lines in a predetermined order;
- a restoration unit which restores residues that are differences between prediction values of the pixel lines and original pixel values of the pixel lines and are included in a received bitstream;
- and
- an addition unit which decodes pixels of the pixel lines by adding the predicted pixel values of the pixel lines and the restored residues.
Dependencies are inferred from the claim text.