Method and apparatus for image scaling using adaptive edge enhancement

摘要

In an image scaling method and apparatus that uses adaptive edge enhancement, a plurality of sets of gradient threshold values and enhancement threshold values correspond respectively to predetermined enhancement modes. The enhancement mode corresponding to a mean pixel value for a one-dimensional pixel array that includes a center pixel to be updated and neighboring pixels of the center pixel is determined so that one of the sets of gradient threshold values and enhancement threshold values corresponding to the selected enhancement mode can be selected. After a sharpness value is computed by adding together absolute values of differences between values of the center pixel and each of the neighboring pixels, one of the enhancement threshold values in the selected set is selected by comparing the sharpness value with the gradient threshold values in the selected set. A sign of the selected enhancement threshold value is then determined such that difference between left side brightness and right side brightness is increased when the selected enhancement threshold value is added to the value of the center pixel.