I've been using Photoshop to retouch photos on windows and would like to try Ubuntu. That's why I'm wondering if I switch to Gimp what features will I lose or gain.
I'm wondering if I switch to Gimp what features will I lose or gain.
Try it. Find out.
Answers here wont really tell you what you'll miss, because only you can know that.
Potentially, answers could tell you of new features you'll gain, but if you already have PS then - other than the glow of using GNU Free Software rather than proprietary Adobe software - I'm not sure GIMP has anything to offer feature-wise.
And don't forget that you don't necessary need to switch, as dual-booting and/or virtualisation are potentially both options that allow you to primarily use Ubuntu but still use Photoshop.
GIMP is based primarily for Web / Screen editing. There's no CMYK support in GIMP because it's not intended for print use. For the most part, you can find a bulk of the essential Photoshop features in Gimp - however, if you're a PS power user like myself, you'll find that different keyboard shortcuts and different tools to do the same task as PS are extremely frustrating.
This isn't directly answering the question, but you can run Photoshop quite nicely in Ubuntu using Wine. See the WineHQ entry for more details.
Photoshop is industry standard so there is much more support for it of course. Also more tools such as brushes and the lot, but with all this comes a price. GIMP is 100% free on the other hand, but you will not have all the same features at hand.
I can't complain... there's an old saying "you get what you pay for".... and you get more than your money's worth with GIMP.
Coming from Photoshop, I found GIMP bewildering and gave up. The whole arrangement of the UI was alien to me.
There is a flavor called GIMPshop that's supposed to be more like Photoshop. I haven't tried it, but it might make things easier on you.
The feature I missed the most when viewing PS tutorials was the brush engine. In PS it is very powerful and you can create all kinds of greatness with it.
Of course, if you are going from PS to Gimp you'll probably hate it but if you are starting out new then Gimp will be an awesome tool ... to a paint. Then you can decide whether to get PS if that's the case.