Oy, have I really had this hanging over my head since 2014? Sorry, Thiago, if you are reading this.
Tip: I think that in addition to --fail and --failpercent, it may also be wise to set --hardfail as well (generally to a larger value than you used for --fail). The complexity here reflects that it's quite tricky to design good "image is close enough" criteria. You want to allow some pixels to differ by a bit -- but not too many -- but also that if any one pixel is TOO far off, that's also a failure even if there is just one. It's tricky to keep straight, and I have to read the docs carefully every time I use it to remind myself which flags mean what. > On May 30, 2017, at 5:52 PM, Ryan Heniser <heni...@yahoo.com> wrote: > > Hi Larry, > > Thank you for taking the time to provide such a thorough response. Sorry, you > had to repeat yourself. I just found Thiago’s post about this from 2014 > (http://lists.openimageio.org/pipermail/oiio-dev-openimageio.org/2014-August/013430.html > > <http://lists.openimageio.org/pipermail/oiio-dev-openimageio.org/2014-August/013430.html>). > Yes, the --diff option with --fail 0.05 and --failpercent 0.1 are working > well to address LSB error for my automated tests. For anyone new to oiiotool, > --fail and --failpercent must go before —diff. > > Thank you, > Ryan > > >> On 31 May 2017, at 5:07 am, Larry Gritz <l...@larrygritz.com >> <mailto:l...@larrygritz.com>> wrote: >> >> I should add that, while -pdiff seemed like a good idea at the time, I'm not >> sure it's any better in practice than using regular --diff with wisely >> chosen epsilons to allow a certain amount of LSB error to not be counted as >> failure. I do that all the time for testsuite image comparisons, where I >> expect just a little bit of error against the reference output, for >> different platforms or different versions of dependent libraries. >> >> Oh my, this is embarrassing. I see now that the oiiotool docs do not even >> explain how those thresholds can be set. So sorry. The undocumented commands >> are --fail, --failpercent, --warn, --warnpercent, --hardfail. It may be >> undocumented in the oiiotool section of the OIIO docs, but the same commands >> are explained in the "idiff" section of the docs (they work the same in the >> two programs). I'll get that oversight fixed. >> >> It's also been suggested that I look into a replacement (or additional) >> perceptual diff based on CIEDE2000 or DE2000K (google them for details). >> Seems like a good idea, but I haven't had time to do it. I'd certainly be >> very supportive if anybody felt like it would be a project they wanted to >> work on and submit it as a PR. >> >> >>> On May 29, 2017, at 10:16 PM, Ryan Heniser <heni...@yahoo.com >>> <mailto:heni...@yahoo.com>> wrote: >>> >>> Ugg… Sorry, I overlooked >>> >>> oiiotool --help >>> ... >>> --pdiff Print report on the perceptual difference of >>> two images >>> >>> >>>> On 30 May 2017, at 2:34 pm, Ryan Heniser <heni...@yahoo.com >>>> <mailto:heni...@yahoo.com>> wrote: >>>> >>>> Is there a popular or de facto industry standard tool for OpenEXR >>>> perceptual image differencing? >>>> >>>> Kind regards, >>>> >>>> ryan heniser >>>> senior shading technical director | ryan.heni...@rsp.com.au >>>> <mailto:ryan.heni...@rsp.com.au> >>>> rising sun pictures | http://www.rsp.com.au <http://www.rsp.com.au/> >>>> +61 8 8400 6400 >>> >>> _______________________________________________ >>> Openexr-devel mailing list >>> Openexr-devel@nongnu.org <mailto:Openexr-devel@nongnu.org> >>> https://lists.nongnu.org/mailman/listinfo/openexr-devel >>> <https://lists.nongnu.org/mailman/listinfo/openexr-devel> >> >> -- >> Larry Gritz >> l...@larrygritz.com <mailto:l...@larrygritz.com> >> >> > -- Larry Gritz l...@larrygritz.com
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