Unsharp mask with php

Is there a built-in function in php to 开发者_Go百科add some extra sharpness on images? Like Photoshops unsharp mask?

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Yes, the easiest way is to use the phpThumb library. Here is a demo of the sharpen feature:

http://phpthumb.sourceforge.net/demo/demo/phpThumb.demo.demo.php#x14

You can apparently also use imageconvolution() in the GD library (phpThumb uses either GD or ImageMagick, whichever is available):

http://www.php.net/manual/en/function.imageconvolution.php