Image encoding apparatus, method of controlling the same, and storage medium

A method of controlling an image encoding apparatus for encoding a video, the method comprising:

• separating a plurality of planes respectively configured in a single component for a frame of an input video;
• performing a wavelet transformation of a plane of interest in the plurality of planes obtained by the separation;
• from each sub-band obtained in the wavelet transformation, extracting in order blocks representing the same region of an image;
• using a quantization parameter, quantizing wavelet transformation coefficients for each of the blocks;
• and
• encoding the wavelet transformation coefficients after the quantizing,
• wherein the quantizing:
• determines, for each of the blocks, a correction parameter for correcting the quantization parameter based on a direct current value and an alternating current value of the block;
• and
• quantizes the wavelet transformation coefficients in accordance with the quantization parameter resulting from correction by the determined correction parameter.

A non-transitory computer-readable storage medium storing a program executable by a computer to perform a method of controlling an image encoding apparatus for encoding a video, the method comprising:

• separating a plurality of planes respectively configured in a single component for a frame of an input video;
• performing a wavelet transformation of a plane of interest in the plurality of planes obtained by the separation;
• from each sub-band obtained in the wavelet transformation, extracting in order blocks representing the same region of an image;
• using a quantization parameter, quantizing wavelet transformation coefficients for each of the blocks;
• and
• encoding the wavelet transformation coefficients after the quantizing,
• wherein quantizing,
• determines, for each of the blocks, a correction parameter for correcting the quantization parameter is determined based on a direct current value and an alternating current value of the block;
• and
• quantizes the wavelet transformation coefficients in accordance with the quantization parameter resulting from correction by the determined correction parameter.