How to split an image vertically using the command line?

Question

Say I have a large 800x5000 image; how would I split that into 5 separate images with dimensions 800x1000 using the command line?

Please don't add the solution to your Q. Mark the answer below as accepted. — slm, Nov 23 '14 at 14:03

score 52 · Answer 1 · edited Nov 30 '21 at 14:51

52

Solved it using ImageMagick's convert -crop geometry +repage:

convert -crop 100%x20% +repage image.png image.png

edited Nov 30 '21 at 14:51

Stephen Kitt

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answered Nov 23 '14 at 15:26

shley

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If you want to apply this to a batch of files, try this: `ls -1 *.png | sed 's,.*,& &,' | xargs -n 2 convert -crop 100%x20% +repage` – JPT Feb 28 '19 at 20:55
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Okay, so `100%x20%` splits vertically and `20%x100%` splits horizontally. – deadfish Mar 09 '20 at 14:23
To place the exports in a subfolder, create that folder and add it to the "sed" part of the command: `ls -1 *.png | sed 's,.*,& subfolder_name/&,' | xargs -n 2 convert -crop 100%x20% +repage` – Tin Man Oct 12 '22 at 09:10
To split a scan of two pages, I had to use the option `-deconstruct`. Without it one of the two files came out as the original with one side blank. – Dude named Ben Feb 07 '23 at 13:32
Seems no need to +repage in latest versions? – Shaohua Li Mar 19 '23 at 05:44
Not working anymore – Niklas Rosencrantz May 18 '23 at 19:50

score 31 · Answer 2 · edited Nov 23 '14 at 14:02

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Using ImageMagick:

$ convert -crop 800x1000 image.png cropped_%d.png

Will create a sequence of files named cropped_1.png, cropped_2.png, and so on.

References

edited Nov 23 '14 at 14:02

slm

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answered Nov 23 '14 at 13:59

outlyer

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The OP said that this solved it using `convert -crop geometry +repage`. For example: `convert -crop 100%x20% +repage image.png image.png`. – slm Nov 23 '14 at 14:06
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`+repage` [considerations](http://www.imagemagick.org/script/command-line-options.php#crop) re: image offset capable formats etc. – Nov 23 '14 at 14:18
How does this compare to @shley's answer? – CMCDragonkai Mar 21 '19 at 06:51
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@CMCDragonkai it's essentially the same, they're using percentages so it will split any size image into 5 vertical slices instead of being written specifically for the 800x5000 case – outlyer Apr 22 '19 at 21:15

Luchostein · Answer 3 · 2020-06-01T23:12:19.690

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Using the "tiles" functionality:

convert image.png -crop 1x5@ out-%d.png

https://www.imagemagick.org/Usage/crop/#crop_tile

edited Jun 01 '20 at 23:12

answered Jun 01 '20 at 23:06

Luchostein

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Newer docs: http://www.imagemagick.org/script/command-line-options.php#crop ('You can add the @ to the geometry argument to equally divide the image into the number of tiles generated.') – cherryblossom Dec 30 '20 at 11:40

score 1 · Answer 4 · answered Mar 15 '18 at 03:36

ImageMagick would crash on me, for the image being too big for it to handle, so I had to resort to other methods.

I ended up using the Python Image Library.

A quick and dirty answer to the OP question follows:

from PIL import Image

im = Image.open("YourImage.yourformat")

for h in range(0, im.height, 1000):
     nim = im.crop((0, h, im.width-1, min(im.height, h+1000)-1))
     nim.save("PartialImage." + str(h) + ".yourformat")

The above code has the final sizes hardcoded, but it can be easily transformed into an full blow script of its own with all inputs parameterized. If one ever needs such a thing.

How to split an image vertically using the command line?

4 Answers4

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