> I just noticed something strange about the PNG images I posted: When I look at
> the small *preview* images here in my post (using the latest version of
> Firefox), they look correct: identical to how they appear on my own machine,
> when viewed in either Photoshop or the Windows Photo Viewer. (BTW, I
> post-processed the images in PS, but only to combine two renders into one post.)
> 
> But when I click on the image previews here-- and the higher-resolution versions
> appear-- the gamma of the images isn't correct! They look darker, with more
> contrast.
> 
> Does anyone else notice this? Right now, I have no idea what's going on, or why
> they appear differently on the same website.
> 
> Honestly, I simply don't trust PNG images to show up consistently or correctly,
> anywhere! :-(  I should have posted them as jpegs.
> 
> 
> 
PNG contain gamma information, JPEG don't.
The problem is not the PNG, it's the application used to display them 
that is to blame. Some correctly use the png's gamma chunk and display 
it corrrectly no mather the actual gamma of the device used, other just 
don't.
JPEG don't have any gamma chunk, whitch makes gamma adjustment 
impossible. So, the display becomes dependent on the gamma setting of 
the device used to display it. If that device have the same gamma as 
that of the author, all is fine, otherwise, the image get to dark or to 
light and washed out.
Typically, a JPEG image made on a PC will look washed out on am Mac, and 
one made on a Mac will look to dark on a PC.
When using PNG, it should not be the case. The image should display the 
same on both platforms.

Post a reply to this message