Re: OpenEXR Perceptual Image Differencing

Larry Gritz <[email protected]> Tue, 30 May 2017 12:37:59 -0700
Newsgroups gmane.comp.video.openexr.devel,gmane.comp.video.openexr.user
Message-ID <[email protected]>
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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 <[email protected]> wrote:
>=20
> Ugg=E2=80=A6 Sorry, I overlooked
>=20
> oiiotool --help
>     ...
>     --pdiff                  Print report on the perceptual difference =
of two images
>=20
>=20
>> On 30 May 2017, at 2:34 pm, Ryan Heniser <[email protected] =
<mailto:[email protected]>> wrote:
>>=20
>> Is there a popular or de facto industry standard tool for OpenEXR =
perceptual image differencing?=20
>>=20
>> Kind regards,
>>=20
>> ryan heniser
>> senior shading technical director | [email protected] =
<mailto:[email protected]>
>> rising sun pictures | http://www.rsp.com.au <http://www.rsp.com.au/>
>> +61 8 8400 6400=20
>=20
> _______________________________________________
> Openexr-devel mailing list
> [email protected]
> https://lists.nongnu.org/mailman/listinfo/openexr-devel

--
Larry Gritz
[email protected]



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<html><head><meta http-equiv=3D"Content-Type" content=3D"text/html =
charset=3Dutf-8"></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" =
class=3D"">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.<div class=3D""><br class=3D""></div><div =
class=3D"">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. &nbsp;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.</div><div class=3D""><br class=3D""></div><div =
class=3D"">It's also been suggested that I look into a replacement (or =
additional) perceptual diff based on&nbsp;<en-clipboard =
class=3D""></en-clipboard>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.<div class=3D""><br =
class=3D""></div><div class=3D""><br class=3D""><div><blockquote =
type=3D"cite" class=3D""><div class=3D"">On May 29, 2017, at 10:16 PM, =
Ryan Heniser &lt;<a href=3D"mailto:[email protected]" =
class=3D"">[email protected]</a>&gt; wrote:</div><br =
class=3D"Apple-interchange-newline"><div class=3D""><meta =
http-equiv=3D"Content-Type" content=3D"text/html charset=3Dutf-8" =
class=3D""><div style=3D"word-wrap: break-word; -webkit-nbsp-mode: =
space; -webkit-line-break: after-white-space;" class=3D""><div =
class=3D"">Ugg=E2=80=A6 Sorry, I overlooked</div><div class=3D""><br =
class=3D""></div><div class=3D""><div class=3D""><font face=3D"monospace, =
monospace" class=3D"">oiiotool --help</font></div><div class=3D""><font =
face=3D"monospace, monospace" class=3D"">&nbsp; &nbsp; =
...</font></div><div class=3D""><font face=3D"monospace, monospace" =
class=3D"">&nbsp; &nbsp; --pdiff &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; =
&nbsp; &nbsp; &nbsp; &nbsp;Print report on the perceptual difference of =
two images</font></div></div><div class=3D""><br class=3D""></div><br =
class=3D""><div class=3D""><blockquote type=3D"cite" class=3D""><div =
class=3D"">On 30 May 2017, at 2:34 pm, Ryan Heniser &lt;<a =
href=3D"mailto:[email protected]" class=3D"">[email protected]</a>&gt; =
wrote:</div><br class=3D"Apple-interchange-newline"><div class=3D""><meta =
http-equiv=3D"Content-Type" content=3D"text/html charset=3Dus-ascii" =
class=3D""><div style=3D"word-wrap: break-word; -webkit-nbsp-mode: =
space; -webkit-line-break: after-white-space;" class=3D""><span =
style=3D"font-family: arial, helvetica, sans-serif; font-size: 16px;" =
class=3D"">Is there a popular or de facto industry standard tool for =
OpenEXR perceptual image differencing?&nbsp;</span><div =
style=3D"font-family: arial, helvetica, sans-serif; font-size: 16px;" =
class=3D""><div class=3D""><br class=3D""></div><div class=3D"">Kind =
regards,</div><div class=3D""><br class=3D""><div class=3D""><span =
name=3D"x" class=3D""></span>ryan heniser<br class=3D"">senior shading =
technical director |&nbsp;<a href=3D"mailto:[email protected]" =
class=3D"">[email protected]</a><br class=3D"">rising sun pictures =
|&nbsp;<a href=3D"http://www.rsp.com.au/" =
class=3D"">http://www.rsp.com.au</a><br class=3D"">+61 8 8400 =
6400&nbsp;</div></div></div></div></div></blockquote></div><br =
class=3D""></div>_______________________________________________<br =
class=3D"">Openexr-devel mailing list<br class=3D""><a =
href=3D"mailto:[email protected]" =
class=3D"">[email protected]</a><br =
class=3D"">https://lists.nongnu.org/mailman/listinfo/openexr-devel<br =
class=3D""></div></blockquote></div><br class=3D""><div =
apple-content-edited=3D"true" class=3D"">
--<br class=3D"">Larry Gritz<br class=3D""><a =
href=3D"mailto:[email protected]" class=3D"">[email protected]</a><br =
class=3D""><br class=3D"">

</div>
<br class=3D""></div></div></body></html>=

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