Method, apparatus and medium for decoding or encoding

An apparatus comprising:

• at least one memory configured to store computer program code;
• and
• at least one processor configured to access the at least one memory and operate according to the computer program code, the computer program code comprising:
• first applying code configured to cause the at least one processor to receive information regarding a sound, video or image data block that is a target data block for encoding or decoding;
• second applying code configured to cause the at least one processor to determine whether at least one of a width or a height of a block size of the target data block is greater than or equal to a predetermined threshold;
• and
• third applying code configured to cause the at least one processor to, if the at least one of the width or the height of the block size of the target block is greater than or equal to the predetermined threshold, perform encoding or decoding of the target data block, but instead of applying a large transform having a size corresponding to the at least one of the width or the height of the block size of the target data block, applying a first transform to a first portion of the target data block, and applying the first transform or a second transform to a second portion of the target data block, wherein at least one of the first transform and the second transform is a low-complexity transform that has a size that is less than the predetermined threshold.

A non-transitory computer-readable storage medium storing instructions that cause one or more processors to:

• receive information regarding a sound, video or image data block that is a target data block for encoding or decoding;
• determine whether at least one of a width or a height of a block size of the target data block is greater than or equal to a predetermined threshold;
• and
• if the at least one of the width or the height of the block size of the target data block is greater than or equal to the predetermined threshold, perform encoding or decoding of the target data block, but instead of applying a large transform having a size corresponding to the at least one of the width or the height of the block size of the target data block, applying a first transform to a first portion of the target data block, and applying the first transform or a second transform to a second portion of the target data block, wherein at least one of the first transform and the second transform is a low-complexity transform that has a size that is less than the predetermined threshold.