Method and apparatus for block-based depth map coding and 3D video coding method using the same

A method for decoding a depth map, the method comprising:

• decoding XOR operation information for each bitplane block contained in the bitstream;
• and
• performing XOR operation information using a restored bitplane block and a reference bitplane block;
• restoring coding mode information for each depth map block, the coding mode information contained in the bitstream, the method being performed when the decoding mode information indicates bitplane coding
• wherein the XOR operation on the restored bitplane block and the reference bitplane block is performed on a bitplane block only in response to the decoded XOR operation information indicating that XOR operation has to be performed, and
• wherein the performing of the SOR operation using the bitplane block and the reference bitplane block comprises:
• decoding a bitstream in units of bitplane to restore a bitplane block;
• adaptively performing XOR operation on the restored bitplane block;
• and
• combining bitplane blocks subjected to XOR operation and/or bitplane blocks not subjected to XOR operation.

A depth map decoding method, comprising:

• decoding coding mode information for each depth map block, the coding mode information contained in a bitstream;
• and
• performing bitplane decoding or Discrete Cosine Transform (DCT)-based decoding on the bitstream in units of blocks according to the decoded coding mode information to restore bitplane blocks,
• wherein the performing of bitplane decoding comprises:
• decoding the bitstream in units of bitplane to restore a bitplane block;
• decoding XOR operation information for each bitplane block contained in the bitstream;
• adaptively performing XOR operation on the restored bitplane block;
• and
• combining bitplane blocks subjected to XOR operation and/or bitplane blocks not subjected to XOR operation, and
• wherein the XOR operation is performed on a bitplane block only in response to the decoded XOR operation information indicating that XOR operation has to be performed.

A method for decoding a depth map block each pixel of which is represented by N bits, the method comprising:

• performing decoding according to block mode information for each bitplane block to restore n (≦N) bitplane blocks;
• adaptively performing XOR operation on each of the n bitplane blocks using a reference bitplane block according to XOR operation information for each of the bitplane blocks;
• and
• combining the n bitplane blocks subjected to and not subjected to the XOR operation,
• wherein if n is less than N, the method further comprises adding (N−n) bits as lower-level bits to each pixel value of the combined bitplane block of the n bitplane blocks, thereby reconstructing the depth map block that is represented by N bits, and
• wherein the XOR operation is performed on a bitplane block only in response to the decoded XOR operation information indicating that XOR operation has to be performed.