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Date: Mon, 24 Nov 2003 17:40:49 +0200 (EET)
Reply-To: Jani Taskinen <sniper@iki.fi>
To: Paul Troughton <php@troughton.org>
Cc: internals@lists.php.net
In-Reply-To: <3BE30005-1E90-11D8-A3ED-000A95D9ABDE@troughton.org>
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References: <3BE30005-1E90-11D8-A3ED-000A95D9ABDE@troughton.org>
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Subject: Re: [PHP-DEV] [PATCH] Image sharpening function for ext/gd
From: sniper@iki.fi (Jani Taskinen)


    There's new function in PHP 5 CVS, imagefilter(),
    I'd guess this would be good addition into that one..
    
    --Jani
    

On Mon, 24 Nov 2003, Paul Troughton wrote:

>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 
> >100 can be used for stronger sharpening. Negative values are treated 
>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.
>
>