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Keith Bauer
11-21-2008, 10:15 AM
I discovered a very nice use of Content Aware Scale in CS4. I commonly need to add canvas to birds in flight images. Here's the tip.

You'll need to be on an editable layer - i.e. not the background layer

Go to Image / Canvas Size and add the amount of canvas you want. Then select Edit / Content Aware Scale. Simply drag your image by the handle in the direction of the added canvas. In most cases you'll have the added canvas you want. If the technique distorts your subject, before you drag the canvas, do the following. Do a rough selection of the subject(s) that you want to protect from distortion. Feather the selection by a few pixels. Then save the selection. By default the selection name will be Alpha1. Then try the Edit / Content Aware Scale and note there is an option in the toolbar called "Protect". From that drop down pick "Alpha1" (or whatever you chose to call your saved selection). Then drag the handle to add your canvas.

If the image has the subject very close to the edge you are trying to expand, it doesn't work as well. The beauty of this technique is that it deals very well with difficult backgrounds with things like diagonal lines, shadows etc. that were problematic before when adding canvas.

Give it a try and see how it works for you.

Doug Brown
11-21-2008, 11:06 AM
Nice tip Keith!

Alfred Forns
11-22-2008, 01:28 PM
Thanks Keith It is one of my favorite new features in CS4 !!!

Gus Hallgren
11-24-2008, 11:25 AM
Hi Keith:

Thanks for your tip on adding canvas with CAS I did quite a bit of experimenting. I found it was easier for me to protect the main image every time by using the Selection tool, when selected, right click on it, click Feather, use default of 5, right click again, click Save Selection, use default (No new name) as when you use the Protect drop down it will read Alpha. I also found out that if I wanted the canvas extended 50 px on any side with CAS I needed to have the canvas size + 100 px initially, and crop to size when finished.

I found that if your main image was close to the edge (One I tried 38 px from the edge) that I it didn't work and all the stretch went to the opposite edge.

However, in a lot of cases CAS will do a decent job of adding a fairly seamless added canvas keeping in mind something has to stretch and CAS is not perfect.

Keith, I would appreciate any contrary comments.

Regards

Uncle Gus

Keith Bauer
11-24-2008, 08:19 PM
No contrary comments from me. I think you've summarized it very well Gus. I agree that you may have to add more canvas than you need and then crop after the fact. Your statement about the main image close the edge (38 px) that didn't work is exactly the same behavior that I noted.

While it doesn't work for every image, in some cases is works Very Very well....

Keith