# Resizing with GIMP



## Josh66 (Dec 2, 2011)

OK, so I'm having issues resizing in GIMP...  Starting with a file around 8000 pixels on the long side and trying to get it down to around 1000 or 800.  It never looks good.  Are there some options I need to change, or do it in steps or something?


Just as an example - I can't seem to resize as good as Flickr does.  I upload full (or close) size pictures, and they generally look OK at any size on Flickr.  When I try to resize an image that large to web sizes - it always looks like ****.  What am I doing wrong?

I have been using the 'scale image' option in the menus.

edit
There are a few different resizing algorithms to pick from, but I don't really know much about that.  Is one better than the others for my situation?  I just use the default.

The options are "Quality":
Cubic <default>
None
Linear
Sinc (Lanczos3)


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## 480sparky (Dec 2, 2011)

I hope you aren't expecting to see the same detail in the smaller image as you do in the original, full size.  I use the None option.... it seems to do the best.

There's a plug-in you can install, Scale in Steps, but I have never seen much improvement with that.


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## Josh66 (Dec 3, 2011)

Nah - I'm just trying to avoid the jagged edges I always seem to get.


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## 480sparky (Dec 3, 2011)

When you resize that much, you're _always_ going to get 'jagged' lines compared to the original.


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## KmH (Dec 3, 2011)

Cubic Hermite spline - Wikipedia, the free encyclopedia

Bicubic interpolation - Wikipedia, the free encyclopedia (Photoshop)

Linear interpolation - Wikipedia, the free encyclopedia

Lanczos resampling - Wikipedia, the free encyclopedia


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## Josh66 (Dec 3, 2011)

Hmm...  I just tried all 4 options on this image:



2011120101 by J E, on Flickr

Resizing it to 10% of the original (6927x8626) size in one operation.  I couldn't tell the difference between Cubic and Linear.  "None" looked bad.  Lanczos seemed to have a slight advantage.

I'm using this image because it has been a particularly hard one for me to resize because of the strings.

This is the result of using the Lanczos resizing and doing it in steps (resizing to 90% untill the desired size was reached):




2011120101 - resized by J E, on Flickr

Looks much better to me.  Tedious, but it works.  I may have to write a script to do it, or see if that plug-in will do the same thing.

I would even say that it looks better than the Flickr resizing...

edit
If you need to show me an example or something, feel free to download it and do what you need to.  Click on the first one to go to my Flickr.  The full size file is there.

I know my profile says 'not ok to edit', but - 1, I'm giving you permission this time, and 2, I don't really consider resizing to be "editing".


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## KmH (Dec 4, 2011)

Well heck. It's GIMP (freeware). 

Is GIMP still stuck with only 8-bit color depth edits?


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## Josh66 (Dec 4, 2011)

KmH said:


> Is GIMP still stuck with only 8-bit color depth edits?


I believe so.

edit
I may be wrong.  If you turn on GEGL, you can perform 'high bit-depth' operations.  I'm not sure how many bits "high" is though.

My googling seems to be saying 24-bit.  That can't be right though ... right?


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