Method and apparatus of encoding/decoding image data based on tree structure-based block division
Disclosed are methods and apparatuses for image data encoding/decoding. A method of decoding an image includes receiving a bitstream in which the image is encoded; obtaining index information for specifying a block division type of a current block in the image; and determining the block division type of the current block from a candidate group pre-defined in the decoding apparatus. The candidate group includes a plurality of candidate division types, including at least one of a non-division, a first quad-division, a second quad-division, a binary-division or a triple-division. The method also includes dividing the current block into a plurality of sub-blocks; and decoding each of the sub-blocks with reference to syntax information obtained from the bitstream.
1. An image decoding method performed by an image decoding apparatus, the image decoding method comprising:
obtaining a flag specifying whether image resizing is enabled, wherein the flag having a first value specifies that the image resizing is enabled and the flag having a second value specifies that the image resizing is not enabled;
obtaining at least one offset for the image resizing based on the flag;
deriving a variable for the image resizing based on the at least one offset; and
decoding a current image based on the image resizing,
wherein the image resizing is performed by scaling a reference image of the current image based on the variable for the image resizing, and
wherein, based on the flag having the second value, the at least one offset for the image resizing is not obtained.
2. An image encoding method performed by an image encoding apparatus, the image encoding method comprising:
determining whether image resizing is enabled or not, wherein a flag specifying whether the image resizing is enabled is encoded, and wherein the flag having a first value specifies that the image resizing is enabled and the flag having a second value specifies that the image resizing is not enabled;
determining a variable for the image resizing, wherein the variable for the image resizing is encoded based on at least one offset for the image resizing; and
encoding a current image based on the image resizing,
wherein the image resizing is performed by scaling a reference image of the current image based on the variable for the image resizing, and
wherein, based on the flag having the second value, the at least one offset for the image resizing is not encoded.
3. A method of transmitting a bitstream comprising:
determining whether image resizing is enabled or not, wherein a flag specifying whether image resizing is enabled is encoded into the bitstream, and wherein the flag having a first value specifies that the image resizing is enabled and the flag having a second value specifies that the image resizing is not enabled;
determining a variable for the image resizing, wherein the variable for the image resizing is encoded into the bitstream based on at least one offset for the image resizing;
encoding a current image based on the image resizing; and
transmitting the bitstream,
wherein the image resizing is performed by scaling a reference image of the current image based on the variable for the image resizing, and
wherein, based on the flag having the second value, the at least one offset for the image resizing is not encoded.