Re: [Tuxpaint-devel] bug in scale down? white goes to grey
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From: Bill K. <nb...@so...> - 2011-07-26 20:39:23
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On Tue, Jul 26, 2011 at 11:26:52AM -0400, Albert Cahalan wrote: > On Mon, Jul 25, 2011 at 12:30 PM, Bill Kendrick <nb...@so...> wrote: > > > Confirmed! autoscale_copy_smear_free() gets called, which in turn > > calls thumbnail(), a wrapper to thumbnail2(). By default, this uses the > > relatively new gamma correction routines. > > (Per http://www.4p8.com/eric.brasseur/gamma.html ) > > Why were the gamma correction routines replaced? > I recall being very careful to ensure exact round-trip > behavior when I wrote the originals. Oh, err, I had totally forgotten about your linear<->sRGB stuff. It has not been replaced. I ended up adding some basic gamma-correction to the thumbnail2() function. I suppose the proper thing to do here would be to replace the pow() calls in thumbnail2() with calls to the sRGB_to_linear and linear_to_sRGB function/array. Oops! -bill! |