Selective Sharpening May Involve Sharpening Only Certain Portions Of an
Image Or a certain percentage of the pixels of an image while avoiding
over-sharpening already sharp areas and the introduction of signal noise
in naturally uniform color and/or sharpness areas. A selective sharpening
tool may selectively sharpen the image based on a user-indicated
sharpening limit. For example, the user may select a particular portion
of an image and specify that the least sharp 30% of the pixels in the
selected image portion should be sharpened. In response, the selective
sharpening tool may determine a sharpness value for each pixel in the
image, rank each pixel based on its sharpness value and sharpen only the
least sharp 30% of the pixels. Thus, a user may selectively sharpen a
certain portion of an image (such as based on percentage of the pixels)
while avoiding overly sharpening already sharp areas.