System and method for roll-off correction in image processing

A method of processing a digital image, the method comprising the steps of:

• receiving image data defining the image, the image data including a plurality of pixels;
• defining a first plurality of roll-off contours, each of the first plurality of roll-off contours including a first plurality of linear segments that define the roll-off contour;
• determining for each pixel in the plurality of pixels which roll-off contour in the first plurality of roll-off contours corresponds to the pixel;
• adjusting luminance of each pixel based on its corresponding roll-off contour in the first plurality of roll-off contours;
• defining a second plurality of roll-off contours, each of the second plurality of roll-off contours including a second plurality of linear segments that define the roll-off contour;
• determining for each pixel in the plurality of pixels which roll-off contour in the second plurality of roll-off contours corresponds to the pixel;
• adjusting color of each pixel based on its corresponding roll-off contour in the second plurality of roll-off contours;
• defining a third plurality of roll-off contours, each of the third plurality of roll-off contours including a third plurality of linear segments that define the roll-off contour;
• determining for each pixel in the third plurality of pixels which roll-off contour in the third plurality of roll-off contours corresponds to the pixel;
• and
• adjusting modulation transform function of each pixel based on its corresponding roll-off contour in the third plurality of roll-off contours.

A method of processing a digital image, the method comprising the steps of:

• receiving image data defining the image, the image data including a plurality of pixels;
• determining for each pixel if the pixel is likely corrupt by comparing each pixel to a plurality of neighboring pixels;
• replacing each pixel determined to be likely corrupt with a statistical function of a plurality of nearby pixels;
• converting the plurality of pixels to a format that includes a luminance component, a first color component and a second color component;
• defining a first plurality of luminance roll-off contours, each of the first plurality of luminance roll-off contours including a first plurality of linear segments that define the luminance roll-off contour;
• determining for each pixel in the plurality of pixels which luminance roll-off contour in the first plurality of luminance roll-off contours corresponds to the pixel;
• adjusting luminance component of each pixel based on its corresponding roll-off contour in the first plurality of roll-off contours;
• defining a second plurality of color roll-off contours, each of the second plurality of color roll-off contours including a second plurality of linear segments that define the color roll-off contour;
• determining for each pixel in the plurality of pixels which color roll-off contour in the second plurality of roll-off contours corresponds to the pixel;
• adjusting first and second color components of each pixel based on its corresponding color roll-off contour in the second plurality of roll-off contours;
• defining a third plurality of MTF roll-off contours, each of the third plurality of MTF roll-off contours including a third plurality of linear segments that define the roll-off contour;
• determining for each pixel in the third plurality of pixels which MTF roll-off contour in the third plurality of roll-off contours corresponds to the pixel;
• and
• adjusting MTF of luminance components of each pixel based on its corresponding MTF roll-off contour in the third plurality of roll-off contours.

A processor, tangibly embodying a program of instructions to perform method steps for digital image processing, comprising the machine executed steps of:

• receiving image data defining the image, the image data including a plurality of pixels;
• defining a plurality of roll-off contours;
• determining for each pixel in the plurality of pixels which roll-off contour in the plurality of roll-off contours corresponds to the pixel;
• adjusting each pixel based on its corresponding roll-off contour.