Method and device for determining a unit of a transform unit used in video signal processing

A method for performing an inverse-transform on depth data based on a size of a transform unit by a decoding apparatus, comprising:

• acquiring, by the decoding apparatus, prediction unit size information indicating a size of a prediction unit and coding unit partitioning information indicating a partitioning depth of a coding unit, wherein the coding unit is symmetrically partitioned into one or more prediction units;
• determining, by the decoding apparatus, maximum partitioning information of the transform unit using the prediction unit size information and the coding unit partitioning information;
• determining, by the decoding apparatus, the size of the transform unit by partitioning a depth block within a maximum partitioning range indicated by the determined maximum partitioning information;
• and
• performing, by the decoding apparatus, the inverse-transform on the depth data based on the determined size of the transform unit,
• wherein the coding unit partitioning information is 0 for a 2N×2N prediction unit, the maximum partitioning information of the transform unit is equal to 0,
• wherein the coding unit partitioning information is 1 for a 2N×2N prediction unit, the maximum partitioning information of the transform unit is equal to 0,
• wherein the coding unit partitioning information is 2 for a 2N×2N prediction unit, the maximum partitioning information of the transform unit is equal to 0 or 1,
• wherein the coding unit partitioning information is 3 for a 2N×2N prediction unit, the maximum partitioning information of the transform unit is equal to 0 or 1,
• wherein the coding unit partitioning information is 0 for a 2N×N or N×2N prediction unit, the maximum partitioning information of the transform unit is equal to 0, 1 or 2,
• wherein the coding unit partitioning information is 1 for a 2N×N or N×2N prediction unit, the maximum partitioning information of the transform unit is equal to 0 or 1,
• wherein the coding unit partitioning information is 2 for a 2N×N or N×2N prediction unit, the maximum partitioning information of the transform unit is equal to 0 or 1,
• wherein the coding unit partitioning information is 3 for a 2N×N or N×2N prediction unit, the maximum partitioning information of the transform unit is equal to 0, and
• wherein N is a natural number.