Image processing apparatus and method

An image processing apparatus in which image data encoded with an orthogonal transformation and a variable length coding are decoded using a variable length decoding and an inverse orthogonal transformation, and resolution of the image data is transformed to a predetermined target resolution, the apparatus comprising:

• a receiving means for receiving the image data;
• an image processing means for decoding and reducing the image data;
• and
• a display means for displaying the image data obtained by the image processing means, wherein the image processing means comprises:
• a decoding means for decoding the image data;
• a resolution obtaining means for obtaining resolution of the original image represented by the image data;
• a frequency selecting means for selecting low frequency components to be used for the inverse orthogonal transformation by comparing the obtained resolution with the target resolution;
• an inverse transforming means for performing an inverse orthogonal transformation on the decoded image data using only the low frequency components selected by the frequency selecting means, or using all of the frequency components;
• reducing means for further reducing the inverse transformed image data;
• and
• a reduction method selecting means for selecting an optimum reduction method from the group consisting of a method using only the inverse transforming means, a method using both the inverse transforming means and reducing means, and a method using only the reducing means based on the obtained resolution and the target resolution.