Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I found there are 2 ways to change the image size in GIMP.

One is "Zoom", another is "Scale".

What is the difference of the 2 ways?

I do see some difference when I zoom (or scale) a TIFF to 600%. The result of zoom is more clear than scale.

share|improve this question

migrated from stackoverflow.com Jun 18 '10 at 5:10

This question came from our site for professional and enthusiast programmers.

add comment

1 Answer 1

up vote 6 down vote accepted

Zoom does not change image size, it affects only how it is presented on screen. It;s like magnification. Scale changes physical image size.

For example, imagine you have 256x256 pixels image. If you zoom it to 50%, image will still be 256x256 pixels, although on screen it will take 128x128 pixels. When you scale that image to 50%, its size will be 128x128 pixels.

share|improve this answer
    
Thank you. I understand it now. But do you know why the quality is difference even in the same level? As I said above, I zoom a TIFF to 600%, and scale the same TIFF to 600%, the quality of zoom is more clear. The scaled image is kind of fuzzy. Thanks. –  Landy Jun 11 '10 at 0:58
    
Are you sure you don't have that backwards? There are multiple algorithms - some are more 'fast' and others are more 'accurate'. You'd want to use a 'fast' algorithm for zoom (since it's happening in response to a user event) and an 'accurate' one for scale (as this would produce a permanant change to the image). There may be other issues as well though - perhaps your scale operation isn't preserving the image's aspect ratio or something else. –  Nate Jun 17 '10 at 22:54
    
@el pescado:Sorry for accepting your answer to late. I just know I should do it after I get a right answer. :) –  Landy Apr 21 '11 at 9:02
    
@Nate, thank you:) –  Landy Apr 21 '11 at 9:03
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.