How to resize images?

Bonita · **Posted:** Sat Jun 18, 2011 1:55 am **(#1)**

GIMP Version: 2.6.10
Operating System: Windows
OS Version: Windows 7 SP1
GIMP Experience: Basic Level

I have looked at multiple tutorials and everything and I can't seem to find the answer I am looking for. I just want to resize an image to 160 x 220 without it distorting or getting that stretched out look. I've tried using the Canvas Size button under images to make the canvas proportioned but when I scale it down it still loses it's quality. Any suggestions?

Thanks,
Bonita.

mahvin · **Joined:** Oct 06, 2010 **Posts:** 4050

From any size image, at any given time?

paynekj · **Posted:** Sat Jun 18, 2011 2:11 am **(#3)**

You could try having a look at this discussion we had about a couple of weeks ago, where we tried a few methods:

viewtopic.php?f=8&t=1866

Although as Mahvin says, unless you start with an image with the same aspect ratio (160x220 = 8x11) you are either going to have to crop it, or distort it.

GnuTux · **Posted:** Sat Jun 18, 2011 2:39 am **(#4)**

Bonita wrote:

I just want to resize an image to 160 x 220 without it distorting or getting that stretched out look.

You'll need to ensure the original image has the same aspect ratio as your target. If you have a 320x440 image, you can scale it to 160x220 without the stretching. If you have a 400x500 image, you'll have to crop it or change the canvas size to get to the proper aspect ratio before resizing to 160x220.

As fas as distortion/pixellation goes, when you size down, you toss away resolution and detail. Nothing you can really do about that. You'll just have to find the technique that works (and looks) the best to you. There are pros and cons to resizing methods and the final result can be somewhat subjective.

Rod · **Joined:** May 16, 2010 **Posts:** 16173

Has anyone ever tried importing an image to Inkscape.Trace the bitmap make the bitmap larger or smaller and then save the image? It's an interesting thought.As you are actually creating a vector that will scale to any size up or down without loss of resolution, and without distortion.

mahvin · **Joined:** Oct 06, 2010 **Posts:** 4050

The way I usually work around resizing to an exact ratio, is first I will scale an image to its lowest (and closest) ratio to my target, and then crop away the excess (depending on whether its the width or height that needs cropping).

For example, a 480 x 640 image being resized to 160 x 220, I would scale the image to 165 x 220, then crop off 5px from the top or bottom of the image.

Bonita · **Posted:** Sat Jun 18, 2011 6:57 pm **(#7)**

I am really lost, to be honest about what you mean.. I know you have to keep the proportions right... But I don't know how you're suppose to do that.. How do you get that 8x11 will go into 160x220? Here.. Let me give you an example of what I am trying to do.
I take *hiresnobg shots a lot. And here is a photo I am currently want to shrink down:
Image
What I do basically is edit the photo and make it so it doesn't look pixelized and then I shrink it down to 160x220.
Sorry for not understanding. D<

mahvin · **Joined:** Oct 06, 2010 **Posts:** 4050

The closest it scales down to is 160 x 245. So, to keep the image proportional would require 25 pixels to be cropped from the height. Seeing that the head of the image is so close to the top, the only reasonable place to crop from is the bottom.

160 divided by 20 = 8
220 divided by 20 = 11

That's the lowest reduced fraction from 20 being the greatest common divisor.

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

Bonita wrote:

I am really lost, to be honest about what you mean.. I know you have to keep the proportions right... But I don't know how you're suppose to do that.. How do you get that 8x11 will go into 160x220? Here.. Let me give you an example of what I am trying to do.
I take *hiresnobg shots a lot. And here is a photo I am currently want to shrink down:
Image
What I do basically is edit the photo and make it so it doesn't look pixelized and then I shrink it down to 160x220.
Sorry for not understanding. D<

8/11=160/220=0,727272727273

Your picture: 1043/1599=0,652282676673 so it's too narrow

Two solutions:

- you cut the height down to 1043*11/8=1434 pixels
- you enlarge the width to 1599*8/11=1163 pixels

To cut some height, use the Crop tool, you an even enforce a dimension or an aspect ratio.

To enlarge:
- Image/Canvas size
- "Unlink" the width and height
- Increase the width to 1163, press the "Center" button,and click "Resize"
- In the picture you will get two checkerboard patterns on the vertical edges
- Image/Layer/New layer and have the new layer filled with white: the wole imlage becomes white, but don't worry
- Image/Layer/Stack/Lower layer and you will get back your image

To scale down: Image/Scale Image (use "Cubic" as the interpolation method)