Image processing apparatus and image processing method

An image processing method of an image processing apparatus including storage means for storing compressed image data, comprising:

• a division step of dividing input image data in the form of packet data into predetermined blocks;
• a compression step of compressing the image data at a first compression ratio for each divided block;
• a measurement step of measuring the data amount of the compressed data;
• a first header information updating step of updating header information of the image data;
• an output step of outputting the image data having the updated header information if the data amount of the image data is not more than a predetermined value;
• a recompression step of recompressing the image data stored in the storage means at a second compression ratio higher than the first compression ratio if the data amount of the image data is not less than the predetermined value;
• and
• a second header information updating step of updating header information of the recompressed image data,
• wherein the recompression step comprises:
• a decoding step of decoding the compressed image data;
• an inverse quantization step of inversely quantizing the image data on the basis of the first compression ratio;
• a quantization step of quantizing the image data by using a predetermined quantization table;
• and
• an encoding step of encoding a quantized conversion coefficient.

An image processing method of an image processing apparatus including two storage means for storing image data compressed at different compression ratios, comprising:

• a division step of dividing input packeted image data into predetermined blocks;
• a first compression step of compressing the image data at a first compression ratio and storing the compressed data in first storage means for each divided block;
• a second compression step of compressing the image data at a second compression ratio and storing the compressed data in second storage means for each divided block;
• a measurement step of measuring the data amount of the image data compressed at the first compression ratio;
• a data discarding step of discarding the image data stored in the first storage means if the data amount of the image data compressed at the first compression ratio is not less than a predetermined value;
• and
• an image data transfer step of storing the image data stored in the second storage means into the first storage means,
• wherein in the first compression step, the image data is kept compressed at the second compression ratio, and
• in the second compression step, the image data is compressed at a third compression ratio higher than the second compression ratio for each divided block.

An image processing apparatus comprising:

• input means for inputting image data in the form of packet data;
• dividing means for dividing the input image data into predetermined blocks;
• compressing means for compressing the image data at a first compression ratio for each divided block;
• measuring means for measuring the data amount of the compressed data;
• first header information updating means for updating header information of the image data;
• storage means for storing the image data;
• output means for outputting the image data having the updated header information if the data amount of the image data is not more than a predetermined value;
• recompressing means for recompressing the image data stored in said storage means at a second compression ratio higher than the first compression ratio if the data amount of the image data is not less than the predetermined value;
• and
• second header information updating means for updating header information of the recompressed image data.

An image processing apparatus comprising:

• input means for inputting image data in the form of packet data;
• dividing means for dividing the input image data into predetermined blocks;
• compressing means for compressing the image data at a first compression ratio for each divided block;
• measuring means for measuring the data amount of the compressed data;
• first header information updating means for updating header information of the image data;
• storage means for storing the image data;
• output means for outputting the image data having the updated header information if the data amount of the image data is not more than a predetermined value;
• recompressing means for recompressing the image data stored in said storage means at a second compression ratio higher than the first compression ratio if the data amount of the image data is not less than the predetermined value;
• and
• second header information updating means for updating header information of the recompressed image data,
• wherein said recompressing means comprises:
• decoding means for decoding the compressed image data;
• inverse quantizing means for inversely quantizing the image data on the basis of the first compression ratio;
• quantizing means for quantizing the image data by using a predetermined quantization table;
• and
• encoding means for encoding a quantized conversion coefficient.

An image processing apparatus comprising:

• input means for inputting packeted image data;
• dividing means for dividing the input image data into predetermined blocks;
• first compressing means for compressing the image data at a first compression ratio for each divided block;
• first storage means for storing the image data compressed at the first compression ratio for each block;
• second compressing means for compressing the image data at a second compression ratio for each divided block;
• second storage means for storing the image data compressed at the second compression ratio for each block;
• measuring means for measuring the data amount of the image data compressed at the first compression ratio;
• data discarding means for discarding the image data stored in said first storage means if the data amount of the image data compressed at the first compression ratio is not less than a predetermined value;
• and
• image data transfer means for storing the image data stored in said second storage means into said first storage means,
• wherein said first compressing means keeps compressing the image data at the second compression ratio, and
• said second compressing means compresses the image data at a third compression ratio higher than the second compression ratio for each divided block.

A computer program for controlling an image processing apparatus including storage means for storing compressed image data, functioning as:

• dividing means for dividing input image data in the form of packet data into predetermined blocks;
• compressing means for compressing the image data at a first compression ratio for each divided block;
• measuring means for measuring the data amount of the compressed data;
• first header information updating means for updating header information of the image data;
• storage means for storing the image data;
• output means for outputting the image data having the updated header information if the data amount of the image data is not more than a predetermined value;
• recompressing means for recompressing the image data stored in said storage means at a second compression ratio higher than the first compression ratio if the data amount of the image data is not less than the predetermined value;
• and
• second header information updating means for updating header information of the recompressed image data.

A computer program for controlling an image processing apparatus including storage means for storing compressed image data, functioning as:

• dividing means for dividing input image data in the form of packet data into predetermined blocks;
• compressing means for compressing the image data at a first compression ratio for each divided block;
• measuring means for measuring the data amount of the compressed data;
• first header information updating means for updating header information of the image data;
• storage means for storing the image data;
• output means for outputting the image data having the updated header information if the data amount of the image data is not more than a predetermined value;
• recompressing means for recompressing the image data stored in said storage means at a second compression ratio higher than the first compression ratio if the data amount of the image data is not less than the predetermined value;
• and
• second header information updating means for updating header information of the recompressed image data,
• wherein said recompressing means functions as:
• decoding means for decoding the compressed image data;
• inverse quantizing means for inversely quantizing the image data on the basis of the first compression ratio;
• quantizing means for quantizing the image data by using a predetermined quantization table;
• and
• encoding means for encoding a quantized conversion coefficient.

A computer program for controlling an image processing apparatus including two storage means for storing image data compressed at different compression ratios, functioning as:

• dividing means for dividing input packeted image data into predetermined blocks;
• first compressing means for compressing the image data at a first compression ratio and storing the compressed data in first storage means for each divided block;
• second compressing means for compressing the image data at a second compression ratio and storing the compressed data in second storage means for each divided block;
• measuring means for measuring the data amount of the image data compressed at the first compression ratio;
• data discarding means for discarding the image data stored in said first storage means if the data amount of the image data compressed at the first compression ratio is not less than a predetermined value;
• and
• image data transfer means for storing the image data stored in said second storage means into said first storage means,
• wherein said first compressing means keeps compressing the image data at the second compression ratio, and
• said second compressing means compresses the image data at a third compression ratio higher than the second compression ratio for each divided block.