How To Resize An Image In GIMP Without Stretching? **UPDATED**

[Kjennings92]

Well, title pretty much says it all. Just wanting to know how you can resize an image in gimp without stretching it. Already tried searching on Youtube, but only found guides/tutorials for Photoshop. :/ Luckily, I'm a quick study, but please do bear in mind that I haven't had much experience at all when it comes to editing. Also, the images that I choose to resize will be downscaled or made bigger (depending) to a custom resolution just to in case anyone here needs to know.

 

 

So if any of you need further details or simply have questions, drop them down in the comments & I'll fill you in! :)

Thanks in advance to anyone who can help!

[Eigenvektor]

Without stretching simply means you need so scale both width and height by the same factor. So if you double the image's width you also have to double its height.

 

Gimp should do that by default, when you use the Image > Scale Image function, just make sure the "Chain" between Width and Height is locked, so changing one dimension changes the other by the same factor. In other words you have to explicitly break the chain for Gimp to resize an image without preserving its aspect ratio.

[minibois]

Can you give an example of what you mean?

What I'm asking, is what exactly do you mean by 'resizing' and 'without stretching it'?

 

Generally when people say "stretching" in the context of an image editor, they mean "making an image wider or taller than it was in the original", so going from one aspect ratio to another. This is done by ensuring the chain icon is set to the 'closed' position:

(These are set to closed and open respectively, with the former making sure the aspect ratio will remain the same)

 

You could also mean "without adding pixels/doing some fancy editing of the pixels", in which case you're location for the None setting under the Interpolation option in the scale tool/context box.

[Kjennings92]

3 minutes ago, Eigenvektor said:

Without stretching simply means you need so scale both width and height by the same factor. So if you double the image's width you also have to double its height.

 

Gimp should do that by default, when you use the Image > Scale Image function, just make sure the "Chain" between Width and Height is locked, so changing one dimension changes the other by the same factor.

So basically, in order to resize an image without stretching it, I would need to keep the Aspect Ratio locked- both dimensions the same in order to get the right result, correct?

[Eigenvektor]

Just now, Kjennings92 said:

So basically, in order to resize an image without stretching it, I would need to keep the Aspect Ratio locked- both dimensions the same in order to get the right result, correct?

Yep, just keep the "chain" shown in the screenshot from @minibois locked. When you change the width to some other value, Gimp will automatically change the height accordingly to preserve the aspect ratio (and vice-versa).

[Kjennings92]

2 minutes ago, minibois said:

Can you give an example of what you mean?

What I'm asking, is what exactly do you mean by 'resizing' and 'without stretching it'?

 

Generally when people say "stretching" in the context of an image editor, they mean "making an image wider or taller than it was in the original", so going from one aspect ratio to another. This is done by ensuring the chain icon is set to the 'closed' position:

(These are set to closed and open respectively, with the former making sure the aspect ratio will remain the same)

 

You could also mean "without adding pixels/doing some fancy editing of the pixels", in which case you're location for the None setting under the Interpolation option in the scale tool/context box.

It's tricky to describe. But let me try to give you an example: say you found an image online that you really like, but you say to yourself, "It would be better if it was a little bit bigger. Hey, I can simply resize the image to my desired resolution/size!" I have noticed when an image is taller than it is wider & you go to resize it, you will get that "stretching" effect. Hopefully that puts it into context for you.  

[minibois]

4 minutes ago, Kjennings92 said:

It's tricky to describe. But let me try to give you an example: say you found an image online that you really like, but you say to yourself, "It would be better if it was a little bit bigger. Hey, I can simply resize the image to my desired resolution/size!" I have noticed when an image is taller than it is wider & you go to resize it, you will get that "stretching" effect. Hopefully that puts it into context for you.  

In that case, this would be what you need:

9 minutes ago, minibois said:

This is done by ensuring the chain icon is set to the 'closed' position:

(These are set to closed and open respectively, with the former making sure the aspect ratio will remain the same)

This option is present in the "Scale" tool or the "Scale image" option under "Image". It ensured if the original image is 2000x1000 and you scale the width to 3000, the height will grow equally as much to 1500. 

I do have to mention though, upscaling an image often does (drastically) lower its quality.

 

P.S. you can drag an image larger using the scale tool, but can also fill in just a number there, or even use some math in there (i.e. you can put "+400" after the number and it will add 400 to the original number. Same goes for -, * and / for subtraction, multiplication and division respectively).

[Eigenvektor]

12 minutes ago, Kjennings92 said:

Hey, I can simply resize the image to my desired resolution/size!"

Well, yes and no.

 

For example if you find an image that is 640 x 480 pixel (which is the 4:3 aspect ratio, used by old CRT monitors) then you can't resize it to 1920 x 1080 (16:9) without either stretching the image or clipping it.

 

To preserve its aspect ratio you can either resize it to 1920 x 1440 or 1440 x 1080. The new image is still 4:3. If you want to fit that on a 16:9 monitor it is going to be stretched, unless you clip the 1920 x 1440 to cut of pixels from the top and/or bottom so the height becomes 1080 as needed.

[Kjennings92]

1 minute ago, Eigenvektor said:

Well, yes and no.

 

For example if you find an image that is 640 x 480 pixel (which is the 4:3 aspect ratio, used by old CRT monitors) then you can't resize it to 1920 x 1080 (16:9) without either stretching the image or clipping it.

 

To preserve its aspect ratio you can either resize it to 1920 x 1440 or 1440 x 1080. The new image is still 4:3. If you want to fit that on a 16:9 monitor it is going to be stretched, unless you clip the 1920 x 1440 to cut of pixels from the top an bottom so the height becomes 1080 as needed.

Well, I'm definitely aware that Aspect Ratio does play a part in how well you can edit/tweak an image. However, what are the differences between editing & "clipping"? Anyone care to fill me in?

[Eigenvektor]

7 minutes ago, Kjennings92 said:

Well, I'm definitely aware that Aspect Ratio does play a part in how well you can edit/tweak an image. However, what are the differences between editing & "clipping"? Anyone care to fill me in?

What I mean is you first resize the 640x480 image to 1920x1440, which preserves its aspect ratio. To make it fit on a 16:9 monitor you'd then remove or "clip" pixels from the image so that its size becomes 1920x1080. Obviously you lose part of the image that way.

 

The other option would be to resize it to 1440 x 1080 and then add pixels to the left and right of the image to make its width 1920. This way you keep the whole image but you now have black bars (or whatever color you chose) on the left and/or right.

 

So clipping is simply on specific type of edit you can do to make it fit ("clipping" goes back to manually editing images with a pair of scissors, cutting some parts off)

[Kjennings92]

3 minutes ago, Eigenvektor said:

What I mean is you first resize the 640x480 image to 1920x1440, which preserves its aspect ratio. To make it fit on a 16:9 monitor you'd then remove or "clip" pixels from the image so that its size becomes 1920x1080. Obviously you lose part of the image that way.

 

The other option would be to resize it to 1440 x 1080 and then add pixels to the left and right of the image to make its width 1920. This way you keep the whole image but you now have black bars (or whatever color you chose) on the left and/or right.

 

So clipping is simply on specific type of edit you can do to make it fit ("clipping" goes back to manually editing images with a pair of scissors, cutting some parts off)

So to clip would mean either adding or removing pixels if I understand correctly, but how is it that done? By adding blank spaces to the edited image(s)...? 

[Eigenvektor]

8 minutes ago, Kjennings92 said:

So to clip would mean either adding or removing pixels if I understand correctly, but how is it that done? By adding blank spaces to the edited image(s)...? 

No, clipping exclusively means removing pixels. Gimp has a clipping tool for that in the toolbox. You can use that to remove or cut off any parts of the image you don't want.

 

Not sure if there's a specific word for adding pixels . You can do that by using the Image > Canvas Size menu. This basically changes the size of the drawing board without changing the image contents themselves, filling the newly added pixels with the background color.

 

This can also be used to make the canvas smaller (i.e clip) and you can say how the remaining image should be positioned (e.g top/left or centered) to specify which parts you want to cut off)

[Kjennings92]

1 minute ago, Eigenvektor said:

No, clipping exclusively means removing pixels. Gimp has a clipping tool for that in the toolbox. You can use that to remove or cut off any parts of the image you don't want.

 

Not sure if there's a specific word for adding pixels . You can do that by using the Image > Canvas Size menu. This basically changes the size of the drawing board without changing the image contents themselves, filling the newly added pixels with the background color.

So it's more like the Cut function, then?

[Eigenvektor]

4 minutes ago, Kjennings92 said:

So it's more like the Cut function, then?

If you mean like Cut/Copy/Paste, not quite. With the clipping tool you select which part of the image you want to keep. The rest is simply removed, resizing the image.

 

With Cut the image size would not change and you could paste it again.

[Kjennings92]

Alright guys, I have a little update for you all. I also posted on the Level1Techs forum about this just to get some extra opinions & all. You can view the post here for the full skimmy: How To Resize Images Without Stretching- Inexperienced & Need Guidance! - Software & Operating Systems - Level1Techs Forums 

 

In the comments, 1 user provided some steps I could try. (Username rxcb) And I have completed all those steps except for the 1 that says to flatten the image. (I have not saved the edited image just yet.) The unfinished image edit is posted below as a screenshot.

 

What I want to know is there any way I can remove the checkerboard borders on the image --Not sure if I used the correct term or not.-- & just save the image but without a background or transparency? 

 

 

So far both posts I made have helped to clear some things up, but it seems like I definitely have much to learn when it comes to image editing... Anyway, if any of need extra details or have any questions for me in return, be sure to ask & I'll reply back! Thanks for all that you have done so far!