> Alain Martel <kua### [at] videotronca> wrote:

>>>
>>> Here's a (hopefully) corrected JPEG version.
>>>
>>
>> Do you mean that you set POV-Ray to save the image as a JPEG ? By
>> default, it saves the images as PNG.
>>
> 
> No, the 2nd image I uploaded (JPEG) was made by taking my original saved PNG
> image (assembled in my old Photoshop v5), re-loading it into PS, and re-saving
> it as JPEG. I trust PS to at least do *that* accurately ;-)  The original
> POV-ray renders were PNG files.
> 
> [Btw, I use Windows 7, with a "system default sRGB" ICC color profile.]
> 
>> The PNG version look good here. (Mozilla Thunderbird) Maybe the
>> application that you use to show the posted image don't handle PNG gamma
>> chunk properly.
> 
> The basic problem is that my old Photoshop apparently saves PNG files with a
> *very* wrong embedded gamma-- 4.4 (!) (I should have known better, and checked
> my PNG image in Ive's IC/Lilysoft viewer app before uploading it; his is the
> only app I have that shows the *true* embedded gamma of the image.) ALL of my
> other viewer apps automatically correct(??) the gamma when presenting the
> image-- which I truly don't understand. In older newsgroup posts, I've read
> various comments that say something like, "A PNG image will appear correct in
> any viewing app". So perhaps my nutty version of Photoshop embeds a gamma value
> when it should not embed anything at all?
> 

OK then, my question is : Why did you post process your image in 
Photoshop ? You could have just posted the original, untouched, PNG.

Was it to resize it ? Then, for that task, Photoshop is gross overkill. 
If I want to do that, I'd use IrfanView. It's lightweight, free, can 
perform the combining of several images as you did and properly handle 
the PNG gamma.

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