Apparatus and method for adjusting sharpness of image

A method for adjusting a sharpened gray level of a target pixel, the target pixel being surrounded with N adjacent pixels, N being a positive integer, each of the N adjacent pixels respectively having an adjacent gray level, the sharpened gray level being generated based on an original gray level of the target pixel and the N adjacent gray levels, said method comprising the steps of:

• checking whether the sharpened gray level is larger than a maximum threshold or smaller than a minimum threshold;
• and
• if the sharpened gray level is larger than the maximum threshold, setting the sharpened gray level as the maximum threshold, and if the sharpened gray level is smaller than the minimum threshold, setting the sharpened gray level as the minimum threshold.

An apparatus for adjusting a sharpened gray level of a target pixel, the target pixel being surrounded with N adjacent pixels, N being a positive integer, each of the N adjacent pixels respectively having an adjacent gray level, the sharpened gray level being generated based on an original gray level of the target pixel and the N adjacent gray levels, said apparatus comprising:

• a checking module for checking whether the sharpened gray level is larger than a maximum threshold or smaller than a minimum threshold;
• and
• a limiting module, if the sharpened gray level is larger than the maximum threshold, the limiting module setting the adjusted gray level as the maximum threshold, and if the sharpened gray level is smaller than the minimum threshold, the limiting module setting the adjusted gray level as the minimum threshold.