Re: jpeg image decompiling

On Thu, 30 Aug 2007 17:59:18 +0200, William Gill <noreply@xxxxxxxxxxxxxxx> wrote:



William Gill wrote:

<http://nl3.php.net/imagecolorat>
I played with imagecolorat() before, but it didn't seem to work with a non indexed color image (i.e. it worked with a gif, but not a jpeg). Reading the spec seemed to confirm that the function returns the color index (not the color), which can then be read for rgb values. I was able to convert the jpeg to an indexed image, then use imagecolorat(), but it meant reducing the original to 256 colors first.
I will try again, using your snippet, and let you know.
further digging says on PHP with GD >= 2.0, imagecolorat() should return rgb on truecolor images. I need to do some more digging and testing.

Indeed. Use print_r(gd_info()); to see the specifics of your gd version.

--
Rik Wasmus

My new ISP's newsserver sucks. Anyone recommend a good one? Paying for quality is certainly an option.
.

Relevant Pages

  • Re: jpeg image decompiling
    ... Thanks, Rik. ... I played with imagecolorat() before, but it didn't seem to work with a non indexed color image (i.e. it worked with a gif, but not a jpeg). ...
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  • Re: jpeg image decompiling
    ... I played with imagecolorat() before, but it didn't seem to work with a non indexed color image. ... Reading the spec seemed to confirm that the function returns the color index, which can then be read for rgb values. ... I need to do some more digging and testing. ...
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