Am 08.09.2017 um 03:12 schrieb LiYanrui:
> clipka <ano### [at] anonymousorg> wrote:
>> Am 07.09.2017 um 14:34 schrieb LiYanrui:
>>> The section 2.3.4.1 in pov-ray tutorial
>>> (http://www.povray.org/documentation/3.7.0/t2_3.html#t2_3_4) said, the following
>>> options
>>>
>>> +w640 +h480 +a0.3 +am1 +fN -d File_Gamma=sRGB
>>> Output_File_Name=gamma_showcase.png
>>>
>>> +w640 +h480 +a0.3 +am1 +fN -d File_Gamma=1.0
>>> Output_File_Name=gamma_showcase_linear.png
>>>
>>> would generate two images and they should look identical in
>>> viewing software. I can not get such results. Why different File_Gammas can
>>> generate same results?
>>
>> Unfortunately, there seems to be a growing pile of crappy image viewing
>> software out there that give **** about the encoding scheme information
>> stored in the PNG file header, and just blindly presume /some/ standard
>> scheme as with other image file formats.
>>
> 
> Thanks you for your detailed explanations! I thought GIMP is not that kind of
> software, but I am wrong. I viewd these two images in Firefox and they look
> identical indeed.

I suspect that most software these days that generates encoding scheme
information also writes full-fledged colour profile information, so that
viewing software isn't frequently tested with images that contain only
encoding scheme info.

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