Comments on: Help me scale an image in Photoshop

Question: Help me scale an image in Photoshop

featherboa — Fri, 20 Feb 2009 06:18:23 -0800

Help me scale an image so that part of it is a specific size using Photoshop CS3.

I've got an image, and I know that I need one part of that image to be a specific size in pixels, is there a way to scale the image so that that part is the correct size and the rest of the image scales appropriately?

I'm using Photoshop CS3 on a Mac.

I can do it by eye using free transform, but that's ridiculously time consuming, and not as accurate as I'd like. Is there another way to do this?

By: devnull

devnull — Fri, 20 Feb 2009 06:27:07 -0800

Since you know the ratio of the portion-height to the full image-height, as well as the target portion height, you can work out the target full image size.

By: le morte de bea arthur

le morte de bea arthur — Fri, 20 Feb 2009 06:35:47 -0800

Get the original dimensions of the area you want to resize. Say its 200 x 100.
Suppose you want to scale that part of the image down to 80 x 40...

This means you're scaling the entire image down to (80/200)*100 = 40% of its original size.

So you just scale the entire image down to 40% within Photoshop, and everything should be fine.

Note I only used the widths as a basic for the calculation. You could just as easily use the heights.

By: featherboa

featherboa — Fri, 20 Feb 2009 06:53:21 -0800

Got it - thanks very much to both of you. I never really seem to think of using maths!