Image encoding/decoding method and device, and recording medium on which bitstream is stored

An image encoding method, comprising:

• deriving residual samples of a current block;
• deriving transform coefficients of the current block by performing transform on the residual samples of the current block;
• and
• encoding the transform coefficients of the current block,
• wherein the transform is performed based on at least one of non-separable primary transform, separable transform, or non-separable secondary transform, and
• wherein the non-separable primary transform is applied based on a size of the current block.

A method for transmitting data for image information, comprising:

• obtaining a bitstream for the image information, wherein the bitstream is generated by deriving residual samples of a current block, deriving transform coefficients by performing transform on the residual samples of the current block, and encoding the transform coefficients of the current block;
• and
• transmitting data including the bitstream,
• wherein the transform is performed based on at least one of non-separable primary transform, separable transform, or non-separable secondary transform, and
• wherein the non-separable primary transform is applied based on a size of the current block.