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View Full Version : Picture color different in preview and photoshop?


nchen
07-23-2004, 11:56 PM
I recently acquired a photo from a windows user. When I opened it in Preview on my mac, the colors look faded out. Then I went over to look at it over on his computer and it looks richer. So I opened it up on my mac using Photoshop and the colors look more like it did on his windows computer. These were not subtle differences; they were eye-detectable.

I tried opening the same picture in Graphics Converter, iPhoto, Preview and Photoshop. Only photoshop was able to give me the "actual" colors as I saw on the windows computer.

Next I tried to download a picture directly from my digital camera. And it looked the same on all aforementioned applications.

So, was it because I acquired the picture from a windows user that Preview was not able to display the colors properly? Or is it because Preview does not load the embedded color profile? Is there anything that can be done so that Preview displays the colors properly? Is there an article somewhere that I can read up on why this happens?

tcascone
07-24-2004, 07:48 AM
I think that different apps have different color pallets, so not all apps display images the same.
Photoshop (being Photoshop) is probably able to read and display more colors than the other apps you mentioned.

Also, when I have exchanged images between Macs and PCs, I've noticed that an image made on a PC needs to be darkened to look right on a Mac, while images made on a Mac need to be brightened to look right on a PC.
There must be some difference in the way the systems display images, but I have no idea what that may be.

aubreyapple
07-24-2004, 11:27 AM
Not an expert on this, but some image formats, like JPEG, contain information about gamma and color correction independent of the actual colors in the image itself. Photoshop apparently honors these corrections and the others do not... or possibly the reverse. I have seen dialog boxes in Photoshop, I think, asking if I want to honor these or not.

This may give you something to look for.

rusto
07-24-2004, 11:33 AM
There's quite a few things going on here.

First off, most Mac users set the Gamma for their monitors to 1.8 while most PC users set theirs to 2.2. This accounts for the "faded" or "richer" looks you are seeing between PC and Mac. Many (but certainly not all) imaging pros on the Mac are now setting their display gamma to 2.2 because of the preponderence of PC users out there that are likely to view their images.

Next, Photoshop allows you to determine (or not) whether to change the colorspace that you view your images in. Unless you look in to the "Color Settings" prefs in Photoshop, it may even be changing the color profile of the image you are view without you even knowing it...and this can cause it to look different on your computer than a differently configured computer.

Different apps do not exactly have "different color pallets" but they may or may not convert an image to a default "color space" before displaying it.

I'm short on time right now to give a more in depth explanation but Googling for "photoshop color management" and/or "photoshop color space" ought to provide many useful links and lead to more answers for you.

Old Toad
07-24-2004, 05:50 PM
Here's a site (http://www.shootsmarter.com/infocenter/wc007.html) that give a pretty clear description of color management.

Hope this has been of some help. Good luck.

nchen
07-25-2004, 05:33 AM
Here's a site (http://www.shootsmarter.com/infocenter/wc007.html) that give a pretty clear description of color management.

Hope this has been of some help. Good luck.

That link help clarify the fact that photoshop does indeed respect the embedded color profile. Nothing was mentioned about the rest of the applications that I have used so I suspect that they are not able to use the embedded color profile.

Anyway, I opened that particular picture in photoshop and exported it again using the embedded color profile. That made the picture look "correct".

Thanks for the link.