When I started writing my CoreImage app (ChocoFlop) I was quite fascinated by CoreImage. I still am but I learnt also just how much work has been done in PhotoShop. You can't replace it in a few weeks of casual coding... I mean the PS developers definitely did a lot of work on the main engine, so that it always answers smoothly even with big images on rather old machines. I spent weeks (of freetime) writing and rewriting the main engine. A lot of it in order to support also unaccelerated machines. CoreImage can be slow specially for zooming and pixellating which is painful in pure CoreImage on a non accellerated beast. Since everything is calculated in real time (when being drawn) if only one step is slow then your app can become pretty unresponsive. Actually for machines with old GPUs it's better to go for OpenGL for zooming/pixellating (for the final display).
Of course PhotoShop is slow as hell to load but once you've loaded it it is pretty fast. In ChocoFlop (which is still pretty unstable, sorry) I saw that I could add features really fast because of all the work that Core Image saves you, not to mention ImageIO (anyone ever tried to write a JPeg2000 encoder himself?).
So you can add features fast. Now, that doesn't mean it's optimized. You'll soon notice that working on a large image in a CoreImage app needs more than just a good GPU. It needs good, proven sofware. And that piece of software currently is PhotoShop.
Now if you look at the future, graphic cards are bound to be really amazing. So if it can do it now very fast on a 1024 pixel image, then it will be able to it in a few years on a 10k pixel image. Just have to be patient :-)
by Jacques Lema — May 25
Of course PhotoShop is slow as hell to load but once you've loaded it it is pretty fast. In ChocoFlop (which is still pretty unstable, sorry) I saw that I could add features really fast because of all the work that Core Image saves you, not to mention ImageIO (anyone ever tried to write a JPeg2000 encoder himself?).
So you can add features fast. Now, that doesn't mean it's optimized. You'll soon notice that working on a large image in a CoreImage app needs more than just a good GPU. It needs good, proven sofware. And that piece of software currently is PhotoShop.
Now if you look at the future, graphic cards are bound to be really amazing. So if it can do it now very fast on a 1024 pixel image, then it will be able to it in a few years on a 10k pixel image. Just have to be patient :-)