Thanks! r
On Thu, Jul 12, 2012 at 3:08 PM, Larry Gritz <[email protected]> wrote: > Aha, good catch! I will merge and backport this. > > -- lg > > > On Jul 12, 2012, at 6:56 AM, Ramon Montoya Vozmediano wrote: > > Hi, > > Some Arnold users have been running into problems when resizing 8b or 16b > images using maketx. > > This change in ./src/libOpenImageIO/imageio.cpp fixes the issue: > > quantize (float value, int quant_black, int quant_white, > int quant_min, int quant_max) > { > - value = Imath::lerp (quant_black, quant_white, value); > + value = Imath::lerp ((float)quant_black, (float)quant_white, value); > return Imath::clamp ((int)(value + 0.5f), quant_min, quant_max); > } > > Imath::lerp lerps a float value between the int values 0 and 255, but > returns a *truncated* int result. It's this step causes the problem, > since rather than choosing the closest quantization step the code was > always choosing the smaller one. > > This was causing white fields to become just almost white after the resize > step in maketx. > > The pull request is here: > > https://github.com/OpenImageIO/oiio/pull/400 > > Best, > > r > > > -- > Larry Gritz > [email protected] > > > > _______________________________________________ > Oiio-dev mailing list > [email protected] > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org > >
_______________________________________________ Oiio-dev mailing list [email protected] http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
