JP2003339047A5

JP2003339047A5 -

Info

Publication number: JP2003339047A5
Application number: JP2002171872A
Authority: JP
Filing date: 2002-06-12
Publication date: 2005-10-13

Claims

Color space conversion means for performing color space conversion on input image data;
A dividing unit that divides the image data that has been color space converted by the color space converting unit into a plurality of regions;
Wavelet transform means for applying wavelet transform to each region divided by the dividing means;
An area designating unit for designating an attention area of the input image data;
Attention level designation means for designating the attention level for each area of interest designated by the area designation means;
A quantization rate setting unit that sets a quantization rate for each region wavelet transformed by the wavelet transform unit according to the degree of attention;
Based on the quantization rate set by the quantization rate setting means, compression control means for controlling compression for each area,
Quantization means for quantizing the region compression-controlled by the compression control means based on the quantization rate;
Entropy encoding means for entropy encoding the data quantized by the quantization means;
Tag processing means for codestream processing the data entropy encoded by the entropy encoding means;
An image compression apparatus comprising:

2. The image compression apparatus according to claim 1, wherein the area divided by the dividing unit is one of a tile, a precinct, and a code block .

2. The image compression apparatus according to claim 1, wherein the area divided by the dividing unit is a combination of any two or three of a tile, a precinct, and a code block .

The said area designation | designated means allocates a number for every said divided | segmented area | region, and designates the number applicable to the said attention area according to the said attention degree. image compression apparatus.

The input image data is a static grayscale image;
The region of interest is a region including a human face;
5. The image compression apparatus according to claim 1, wherein a quantization rate in the region of interest is set lower than that in other regions .

When the quantization rate of the region of interest is set higher than the other regions, the image quality of the region of interest becomes coarse, and the quantization rate of the region of interest is set lower than the other regions. In this case, the image compression apparatus according to claim 1, wherein the image quality of the attention area is high definition .

6. The image compression apparatus according to claim 5, wherein a tile size of the tile is set so as to cover a portion of a human face in the input image data .

Color space conversion means for performing color space conversion on input image data;
A dividing unit that divides the image data that has been color space converted by the color space converting unit into a plurality of regions;
Wavelet transform means for performing wavelet transform for each area divided by the dividing means;
Quantization means for quantizing the wavelet coefficients wavelet transformed by the wavelet transformation means;
Bit plane dividing means for dividing the bit plane quantized by the quantization means for each region;
A bit plane setting means for designating a region of interest in the input image data and setting a bit plane division different from other regions for the region of interest;
Entropy coding means for performing entropy coding based on the bit plane division set by the bit plane setting means;
Code stream processing means for generating a code stream from data entropy encoded by the entropy encoding means;
An image compression apparatus comprising:

Color space conversion means for performing color space conversion on input image data;
Wavelet transform means for wavelet transforming the image data color space transformed by the color space transform means;
Quantization means for quantizing the wavelet coefficients wavelet transformed by the wavelet transformation means;
Dividing means for dividing the data quantized by the quantization means into a plurality of regions;
Area designating means for designating a region of interest in the input image data;
Bit plane division designation means for dividing a bit plane for each area divided by the dividing means;
Division control means for setting bit plane division according to bit plane division for each area designated by the bit plane division designation means;
Bit plane dividing means for dividing the wavelet coefficients quantized by the quantization means into layers based on the bit plane division set by the division control means;
Entropy encoding means for entropy encoding the bit-plane divided data;
Code stream processing means for generating a code stream from data entropy encoded by the entropy encoding means;
An image compression apparatus comprising:

The image compression apparatus according to claim 8 or 9, wherein the area divided by the dividing unit is one of a tile, a precinct, and a code block .

10. The image compression apparatus according to claim 8, wherein the area divided by the dividing unit is a combination of any two or three of a tile, a precinct, and a code block .

12. The image compression apparatus according to claim 8, wherein the area designating unit assigns a number to each of the divided areas and designates a number corresponding to the attention area .