Image compression device, image decompression device, image compression/decompression device, program for executing on a computer to perform functions of such devices, and recording medium storing such a program

An image compression method, comprising:

• dividing an image into a plurality of regions;
• applying a wavelet transform to the plurality of regions;
• designating a region of interest for a part of the image that is of interest;
• setting a level of interest for each region of interest;
• setting a quantization rate for each wavelet transformed region, according to the level of interest, wherein when the quantization rate of the region of interest is set higher than quantization rates of the other regions, the image quality of the region of interest becomes coarser, while, when the quantization rate of the region of interest is set lower than quantization rates of the other regions, the image quality of the region of interest becomes finer;
• controlling compression for each region based on the quantization rate;
• performing quantization based on the quantization rate on the each region after compression;
• and performing entropy encoding on the quantized data.

An article of manufacture having one or more computer-readable storage media storing instructions thereon which, when executed by a system, cause the system to perform an image compression method comprising:

• dividing an image into a plurality of regions;
• applying a wavelet transform to the plurality of regions;
• designating a region of interest for a part of the image that is of interest;
• setting a level of interest for each region of interest;
• setting a quantization rate for each wavelet transformed region, according to the level of interest, wherein when the quantization rate of the region of interest is set higher than quantization rates of the other regions, the image quality of the region of interest becomes coarser, while, when the quantization rate of the region of interest is set lower than quantization rates of the other regions, the image quality of the region of interest becomes finer;
• controlling compression for each region based on the quantization rate;
• performing quantization based on the quantization rate on the each region after compression;
• and
• performing entropy encoding on the quantized data.