Method and device for encoding three-dimensional image, and method and device for decoding three-dimensional image

A method of decoding a three-dimensional image including a point cloud, the method comprising:

• receiving a bitstream;
• obtaining, from the bitstream, information related to down-sampling and data in which a two-dimensional image is compressed;
• up-scaling at least one down-sampled patch included in the two-dimensional image, based on the information related to the down-sampling;
• and
• reconstructing the point cloud by restoring color information and position information of points, based on the up-scaled at least one down-sampled patch included in the two-dimensional image,
• wherein the information related to the down-sampling includes a predefined rule, and
• wherein the predefined rule is a table indicating a size of blocks into which the at least one patch is divided and indicating a predefined position at which a point is preserved from the blocks.

A device for decoding a three-dimensional image including a point cloud, the device comprising:

• a receiver configured to receive a bitstream;
• and
• at least one processor configured to:
• obtain, from the bitstream, information related to down-sampling and data in which a two-dimensional image is compressed,
• up-scale at least one down-sampled patch included in the two-dimensional image based on the information related to the down-sampling, and
• reconstruct the point cloud by restoring color information and position information of points based on the up-scaled two-dimensional image,
• wherein the information related to the down-sampling includes a predefined rule, and
• wherein the predefined rule is a table indicating a size of blocks into which the at least one patch is divided and indicating a predefined position at which a point is preserved from the blocks.