Image processing apparatus and method

An image processing apparatus comprising:

• a) input means for inputting color image data;
• b) conversion means for converting color image data input by said input means into color image data in a color difference system color space;
• c) processing means for executing correction processing for luminance component data of the color image data converted by said conversion means;
• and
• d) encoding means for encoding the luminance component data processed by said processing means, and color difference component data of the color image data converted by said conversion means.

An image processing apparatus comprising:

• a) input means for inputting color image data which is compression-encoded in a color difference system color space;
• b) decoding means for decoding the color image data input by said input means;
• c) processing means for executing correction processing for luminance component data of the color image data decoded by said decoding means;
• and
• d) conversion means for performing color space conversion on the basis of the luminance component data processed by said processing means, and color difference component data of the color image data decoded by said decoding means.

An image processing apparatus comprising:

• a) input means for inputting color image data;
• b) first conversion means for performing pixel density conversion for first component data of the color image data;
• and
• c) second conversion means for performing pixel density conversion for second component data of the color image data,
• wherein said first conversion means performs the pixel density conversion to assure higher quality than said second conversion means.

An image processing method comprising:

• a) the input step of inputting color image data which is compression-encoded in a color difference system color space;
• b) the decoding step of decoding the color image data input in the input step;
• c) the processing step of executing correction processing for luminance component data of the color image data decoded in the decoding step;
• and
• d) the encoding step of encoding the luminance component data processed in the processing step, and color difference data of the color image data decoded in the decoding step.

An image processing method comprising:

• a) the input step of inputting color image data;
• b) the conversion step of converting color image data input in the input step into color image data in a color difference system color space;
• c) the processing step of executing correction processing for luminance component data of the color image data converted in the conversion step;
• and
• d) the encoding step of encoding the luminance component data processed in the processing step, and color difference component data of the color image data converted in the conversion step.

An image processing method comprising:

• a) the input step of inputting color image data which is compression-encoded in a color difference system color space;
• b) the decoding step of decoding the color image data input in the input step;
• c) the processing step of executing correction processing for luminance component data of the color image data decoded in the decoding step;
• and
• d) the conversion step of performing color space conversion on the basis of the luminance component data processed in the processing step, and color difference component data of the color image data decoded in the decoding step.

An image processing method comprising:

• a) the input step of inputting color image data;
• b) the first conversion step of performing pixel density conversion for first component data of the color image data;
• and
• c) the second conversion step of performing pixel density conversion for second component data of the color image data,
• wherein the first conversion step performs the pixel density conversion to assure higher quality than in the second conversion step.