Block mode encoding/decoding method and apparatus, and method and apparatus for image encoding/decoding using the same
The present disclosure relates to method and apparatus for block mode encoding/decoding and a method and apparatus for video encoding/decoding using the same. The disclosure provides a block mode encoding apparatus that predicts the block mode of a current block and encodes the block mode of the current block depending on whether the block mode of the current block is same as the block mode predicted, to output encoded mode information. The disclosure can reduce the quantity of bits used to encode information on the block mode, thus enhancing the efficiency of video compression.
1. A video encoding apparatus for encoding an image using a block mode, comprising:
a block mode predictor configured to predict a block mode of a current block; and
a block mode encoder configured to encode mode information of the current block depending on whether the predicted block mode of the current block is identical to a determined block mode of the current block,
wherein the block mode predictor is configured to predict the block mode of the current block using a history table which includes previously determined block mode information according to a plurality of block modes of neighboring blocks of the current block.
2. The video encoding apparatus of claim 1 , wherein the block mode encoder is configured to encode a bit flag as the mode information when the predicted block mode of the current block is identical to the determined block mode of the current block, and the bit flag indicates that the predicted block mode of the current block is identical to the determined block mode of the current block.
3. The video encoding apparatus of claim 1 , wherein the block mode encoder is configured to encode a bit flag and the determined block mode of the current block as the mode information when the predicted block mode of the current block is not identical to the determined block mode of the current block, and the bit flag indicates that the predicted block mode of the current block is not identical to the determined block mode of the current block.
4. The video encoding apparatus of claim 2 , wherein the bit flag comprises a single bit.
5. A video encoding method for encoding an image using a block mode, comprising:
predicting a block mode of a current block using a history table which includes previously determined block mode information according to a plurality of block modes of neighboring blocks of the current block; and
encoding mode information of the current block depending on whether the predicted block of the current block is identical to a determined block mode of the current block.
6. A video decoding apparatus for decoding an image using a block mode, the video decoding apparatus comprising:
a bit flag comparator configured to extract a bit flag from encoded mode information and determine whether the bit flag indicates that the block mode of the current block is to be predicted;
a block mode predictor configured to predict the block mode of the current block and to output the predicted block mode as the block mode of the current block when a value of the bit flag indicates that the block mode of the current block is to be predicted; and
a block mode decoder configured to extract an encoded block mode of the current block from the encoded mode information, to decode the encoded block mode to generate a reconstructed block mode of the current block, and to output the reconstructed block mode as the block mode of the current block when a value of the bit flag indicates that the block mode of the current block is not to be predicted,
wherein the block mode predictor is configured to predict the block mode of the current block using a history table which includes previously determined block mode information according to a plurality of block modes of neighboring blocks of the current block.
7. The video decoding apparatus of claim 6 , wherein the bit flag comprises a single bit.
8. A video decoding method for decoding an image using a block mode, the video decoding method comprising:
extracting a bit flag from an encoded mode information and determining whether the bit flag indicates that the block mode of the current block is to be predicted;
when a value of the bit flag indicates that the block mode of the current block is to be predicted, predicting the block mode of the current block using a history table which includes previously determined block mode information according to a plurality of block modes of neighboring blocks of the current block and outputting the predicted block mode of the block mode as the block mode of the current block;
when a value of the bit flag indicates that the block mode of the current block is not to be predicted, extracting an encoded block mode of the current block from the encoded mode information;
decoding the encoded block mode to reconstruct a block mode of the current block; and
outputting the reconstructed block mode of the current block as the block mode of the current block.
9. A video decoding apparatus for decoding an image using a block mode, comprising:
a bit flag comparator configured to extract a bit flag from a bitstream and to determine whether the bit flag indicates that a block mode of a current block mode is to be predicted;
a block mode predictor configured to predict the block mode of the current block and to output the predicted block mode as the block mode of the current block when a value of the bit flag indicates that the block mode of the current block is to be predicted;
a block mode decoder configured to extract an encoded block mode of the current block from the bitstream, to decode the encoded block mode to generate a reconstructed block mode of the current block and to output the reconstructed block mode as the block mode of the current block when a value of the bit flag indicates that the block mode of the current bock is not to be predicted; and
a block pattern decoder configured to extract a coded block pattern from the bitstream and to decode the coded block pattern according to the block mode of the current block,
wherein the block mode predictor is configured to predict the block mode of the current block using a history table which includes previously determined block mode information according to a plurality of block modes of neighboring blocks of the current block.
10. The video decoding apparatus of claim 9 , wherein the bit flag comprises a single bit.
11. A video decoding method of decoding an image using a block mode, the video decoding method comprising:
extracting a bit flag from a bitstream and determining whether the bit flag indicates that the block mode of a current block mode is to be predicted;
when a value of the bit flag indicates that the block mode of the current block is to be predicted, predicting the block mode of the current block using a history table which includes previously determined block mode information according to a plurality of block modes of neighboring blocks of the current block, and
outputting the predicted block mode as the block mode of the current block;
when a value of the bit flag indicates that the block mode of the current block is not to be predicted, extracting an encoded block mode of the current block from the bitstream, decoding the encoded block mode to generate a reconstructed block mode of the current block, and outputting the reconstructed block mode of the current block as the block mode of the current block; and
extracting a coded block pattern from the bitstream and decoding the coded block pattern according to the block mode of the current block to reconstruct the current block.