[PATCH] Image sharpening function for ext/gd

Hello, I was surprised to find that, although the GD image-handling functions shipped with PHP do many useful things very well, there's no function to sharpen an image. I found a few posts bemoaning this absence, and therefore attach a patch which adds the function int imagesharpen ( resource im, int pct ) It performs the sharpening in-place. pct is the degree of sharpening to be applied: 0 does nothing; 100 gives a quite noticeable effect. Values

as 0. The routine only sharpens truecolor images, as it rarely makes sense to attempt the operation on palletted images. It's a simple linear sharpening routine using a 3x3 kernel, rather than the more flexible, but slower, unsharp masking approach used in e.g. Photoshop, Imagemagick. However it's very effective at making resampled photographic images (such as thumbnails) look a little more crisp. I've built and tested it using gcc 3.3 under Mac OS X 10.3.1. There's nothing I'd expect to be platform-dependent in it. The attached patch is against php4-STABLE-200311202030, but it should work with most varieties of php-4.3.4, as the new code is fairly self-contained. This is my first patch for PHP. Is there anything else I should do, beyond posting it here? Many thanks, Paul.