View Full Version : image resize

05 May 2002, 11:14 PM
Hey guys and gals....

I got a problem and am not sure how to fix it.....

I created a texture map at 1200 x 1200. and now I'd like to resize it to 256x256.

When I do it using..... Image>Image size
the end result is blurry. I am using Bicubic to resample the image at 72 pixels/inch.

Any tips would be seems like it should be a simple operation.

Thanks, T:thumbsup:

Kim Oravecz
05 May 2002, 12:18 AM
Hm, that is a pretty drastic reduction if you think about it. You are going from 1.4 million pixels total to 65,000 pixels. That's a lot of pixels to throw out! So you basically are throwing out a lot of detail and data when you reduce that much. So that's why it's blurry - you are throwing out quite a bit of detail.

I'm thinking the best you could do is to go ahead and do the reduction but then use the unsharp mask filter to try and sharpen it back up again.

Good luck!

. . . Kim

05 May 2002, 12:29 AM
Hi Kim

thanks for the info.....actually my intent was to do it at a large size and then resize it to a smaller size. My thought was the smaller image would be a higher quality cause the pixels would be more dense...i guess that's not the case.

I'll give the unsharpen maks a try.

thanks again

Kim Oravecz
05 May 2002, 12:36 AM
Yeah, it's true that you should work a bit larger and then reduce - but you are doing a reduction of 4.5 times the original size. Go for only twice the size.

Usually when I'm creating textures I try to work twice the size I'm going to want in the final texture.

Also - try this little trick for your sharpening: Convert your image to Lab mode (Image -> Mode -> Lab) and go to your channels palette. Click on the "L" channel. This is basically where all the luminosity data is that is in your image. The 'a' channel contains the red/green color info and the 'b' channel contains the blue/yellow color info.

Anyways, when you click on the L channel you will see that only the luminosity data is being displayed in your image. Go ahead and do the unsharp mask. You will be sharpening the luminosity (basically the detail of the image) only.

Then convert back to RGB.

Hope this helps you somehow!


. . . Kim

05 May 2002, 12:39 AM
thanks kim...

hmm...i shold have asked the question before i started texturing....oh well. i'll know for next time.

i'll try the LAB.....


CGTalk Moderation
01 January 2006, 07:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.