Image processor

An image processor comprising:

• a coefficient memory for storing coefficient data for image enlargement and image reduction, each related with a horizontal direction or a vertical direction;
• a coefficient read-out controller for reading out corresponding coefficient data from the coefficient memory according to an enlargement/reduction selection signal and selecting either image enlargement or image reduction, each related with either the horizontal direction or vertical direction;
• a characteristic variable filter for executing filter processing corresponding to either image enlargement processing or image reduction processing according to the coefficient data read out by the coefficient read-out controller, the characteristic variable filter comprising a horizontal characteristic variable filter for executing either filter processing for horizontal image enlargement or image reduction and a vertical characteristic variable filter for vertical image enlargement or image reduction;
• an image memory;
• a contour correction circuit;
• and selector groups provided in a preceding stage and subsequent stage of each characteristic variable filter and image memory respectively and connected to one another, wherein when the enlargement/reduction selection signal for vertical reduction and horizontal reduction is selected by the selector groups, the processing is set to proceed sequentially through the horizontal characteristic variable filter, the vertical characteristic variable filter, the image memory and the contour correction circuit;
• when the enlargement/reduction signal is for vertical reduction and horizontal enlargement, the processing is set to proceed sequentially through the vertical characteristic variable filter, image memory, horizontal characteristic variable filter and the contour correction circuit;
• when the enlargement/reduction selection signal is for vertical enlargement and horizontal reduction, the processing is set to proceed sequentially through the horizontal characteristic variable filter, the image memory, the vertical characteristic variable filter and the contour correction circuit;
• and when the enlargement/reduction selection signal is for vertical enlargement and horizontal enlargement, the processing is set to proceed sequentially through the contour correction circuit, the image memory, the horizontal characteristic variable filter and the vertical characteristic variable filter.

An image processor comprising:

• a coefficient memory for storing coefficient data for image enlargement and image reduction, each related with a horizontal direction or a vertical direction;
• a coefficient read-out controller for reading out corresponding coefficient data from the coefficient memory according to an enlargement/reduction selection signal and selecting either image enlargement or image reduction, each related with either the horizontal direction or vertical direction;
• a characteristic variable filter for executing filter processing corresponding to either image enlargement processing or image reduction processing according to the coefficient data read out by the coefficient read-out controller, the characteristic variable filter comprising a horizontal characteristic variable filter for executing either filter processing for horizontal image enlargement or image reduction and a vertical characteristic variable filter for vertical image enlargement or image reduction;
• an image memory;
• a contour correction circuit;
• and selector groups provided in a preceding stage and subsequent stage of each characteristic variable filter and image memory respectively and connected to one another, wherein when the enlargement/reduction selection signal for vertical reduction and horizontal reduction is selected by the selector groups, the processing is set to proceed sequentially through the horizontal characteristic variable filter, the vertical characteristic variable filter, the image memory and the contour correction circuit;
• when the enlargement/reduction selection signal is for vertical reduction and horizontal enlargement, the processing is set to proceed sequentially through the contour correction circuit, the vertical characteristic variable filter, the image memory and the horizontal characteristic variable filter;
• when the enlargement/reduction selection signal is for vertical enlargement and horizontal reduction, the processing is set to proceed sequentially through the contour correction circuit, the horizontal characteristic variable filter, the image memory and the vertical characteristic variable filter;
• and when the enlargement reduction selection signal is for vertical enlargement and horizontal enlargement, the processing is set to proceed sequentially through the contour correction circuit, the image memory, the horizontal characteristic variable filter and the vertical characteristic variable filter.

An image processor comprising:

• a coefficient memory for storing coefficient data for image enlargement and image reduction;
• a correction read-out controller for reading out corresponding coefficient data from the coefficient memory according to an enlargement/reduction selection signal;
• a characteristic variable filter for executing filter processing corresponding to either image enlargement processing or image reduction processing according to the coefficient data read out by the coefficient read-out controller;
• an image memory;
• a contour correction circuit comprising a horizontal contour sampler for sampling a contour component in a horizontal direction, a vertical contour sampler for sampling a contour component in a vertical direction, a first adder for adding the contour component sampled by the horizontal contour sampler to the contour component sampled by the vertical contour sampler and a second adder for adding a contour component outputted from the first adder to image data to be inputted to the contour correction circuit for outputting image data corrected for contour;
• and selector groups provided in a preceding stage and subsequent stage of each characteristic variable filter and image memory respectively and connected to one another, wherein the selector groups set the processing of an inputted video signal to proceed sequentially through the contour correction circuit, image memory and characteristic variable filter when the enlargement/reduction selection signal is for image enlargement processing and the processing of the inputted video signal is set to proceed sequentially through the characteristic variable filter, image memory and contour correction circuit when the enlargement/reduction selection signal is for image reduction processing.