How do I write a custom auto-crop script using the GIMP?

Question

I have a bunch of screen shots and I'd like to crop out the window border. I would like to crop them all using a script.

I have access to the GIMP, but not photoshop so I assumed that the GIMP would be the best tool to use. I have not scripted with the GIMP before, so I looked up some GIMP crop scripts. The ones I found are all similar to what I want, but not quite. I thought it would be a simple matter to alter the script to what I need. But since I am not familiar with the scripting language it is proving more difficult than I thought. I found a great auto crop script here. Can someone help me customize it for what I need?

    (define (script-fu-rs-center-crop filename outfilename width height)

  (let* ((image (car (gimp-file-load RUN-NONINTERACTIVE filename filename)))
          (drawable (car (gimp-image-get-active-layer image))))
          (let* ((original-width (car (gimp-image-width image)))
               (original-height (car (gimp-image-height image)))
               (new-width original-width)
               (new-height original-height)
               (offset-x 0)
               (offset-y 0))

               (if (<= (/ original-width original-height) (/ width height))
                   (gimp-image-crop image original-width (* original-width (/ height width)) 0 (/ (- original-height (* original-width (/ height width))) 2) )
                   (gimp-image-crop image (* original-height (/ width height)) original-height (/ (- original-width (* original-height (/ width height))) 2) 0)
               )
           )

  (set! drawable (car (gimp-image-get-active-layer image)))

(gimp-file-save RUN-NONINTERACTIVE image drawable outfilename outfilename)
     (gimp-image-delete image)))

The overall dimensions are not the same for all the photos. But they do all have the same number of pixels on the top, left, right and bottom that I want to crop out. So let's say the image has pixel dimensions width and height and I want to remove t_junk pixels off the top, b_junk pixels off the bottom, l_junk pixels off the left, and r_junk pixels off the right. So I want the new image dimensions to be width - l_junk - r_junk and height - t_junk - b_junk.

Why not use `imagemagick`? It's `convert` method can be quite simple. — Blender, Apr 27 '11 at 22:29

theChrisKent · Accepted Answer · 2011-08-31T15:13:16.220

Edger Script

I have written a custom GIMP script that does exactly what you have asked for. Just paste the following into a text document and save it with a .scm extension in your GIMP scripts folder (the path can be found/created in Edit > Preferences > Folders > Scripts):

(define (script-fu-wirebear-edger filename outfilename top right bottom left)
(let* (
    (img (car (gimp-file-load RUN-NONINTERACTIVE filename filename)))
    (owidth (car (gimp-image-width img)))
    (oheight (car (gimp-image-height img)))
    (width (- owidth (+ right left)))
    (height (- oheight (+ top bottom)))
      )

   ;Crop Image
    (gimp-image-crop img width height left top)

   ;Save
    (gimp-file-save RUN-NONINTERACTIVE
        img
        (car (gimp-image-active-drawable img))
        outfilename
        outfilename)

   ;Cleanup
    (gimp-image-delete img)
))
(script-fu-register "script-fu-wirebear-edger"
    "Edger"
    "Removes junk from the edges of an image"
    "Chris Kent"
    "WireBear.com"
    "August 2011"
    "RGB* GRAY*"
    SF-STRING "Filename" ""
    SF-STRING "OutputFilename" ""
    SF-VALUE "TopEdge" "0"
    SF-VALUE "RightEdge" "0"
    SF-VALUE "BottomEdge" "0"
    SF-VALUE "LeftEdge" "0"
)
script-fu-wirebear-edger()

This script takes in the input filename, the output filename and the number of pixels to shave off on each side. You can run the command from Windows (Assuming you have GIMP setup as an environment variable) like this (Be sure to escape special characters as shown and place all on one line):

C:>gimp-2.6 -i -c -b
   "(script-fu-wirebear-edger \"C:\\Users\\You\\Desktop\\Images\\1.png\" 
   \"C:\\Users\\You\\Desktop\\Images\\1_edged.png\" 10 30 25 5)"
   -b "(gimp-quit 0)"

Or you can run it in the Script-Fu Console (Filters > Script-Fu > Console) - regardless of OS like this:

(script-fu-wirebear-edger "C:\\Users\\You\\Desktop\\Images\\1.png" 
"C:\\Users\\You\\Desktop\\Images\\1_edged.png" 10 30 25 5)

Batch Edger Script

In order to run the Edger script on multiple images, you can use the following script in conjunction with the above script (You will need both in your Scripts folder):

(define (script-fu-wirebear-batch-edger pattern outsuffix top right bottom left)
(let* (
    (filelist (cadr (file-glob pattern 1)))
    (filename "")
    (outfn "")
      )
    (while (not (null? filelist))
        (set! filename (car filelist))
        (set! outfn 
            (string-append 
                (string-append 
                    (substring filename 0 (- (string-length filename) 4))
                    outsuffix)
                (substring filename (- (string-length filename) 4))
            )
        )
        (script-fu-wirebear-edger filename outfn top right bottom left)
        (set! filelist (cdr filelist))
    )
))
(script-fu-register "script-fu-wirebear-batch-edger"
    "Batch Edger"
    "Removes junk from the edges of a series of images"
    "Chris Kent"
    "WireBear.com"
    "August 2011"
    "RGB* GRAY*"
    SF-STRING "Pattern" "*.png"
    SF-STRING "OutputSuffix" "_edged"
    SF-VALUE "TopEdge" "0"
    SF-VALUE "RightEdge" "0"
    SF-VALUE "BottomEdge" "0"
    SF-VALUE "LeftEdge" "0"
)
script-fu-wirebear-batch-edger()

The script takes in a search pattern to match target images, a suffix to add to the file name and the number of pixels to shave off on each side of every image. You can run the command from Windows (Assuming you have GIMP setup as an environment variable) like this (Be sure to escape special characters as shown and place all on one line):

C:>gimp-2.6 -i -c -b
   "(script-fu-wirebear-batch-edger \"C:\\Users\\You\\Desktop\\Images\\*.png\" 
   \"_edged\" 10 30 25 5)"
   -b "(gimp-quit 0)"

Or you can run it in the Script-Fu Console (Filters > Script-Fu > Console) - regardless of OS like this:

(script-fu-wirebear-batch-edger "C:\\Users\\You\\Desktop\\Images\\*.png"
"_edged" 10 30 25 5)

**AWESOME!!** Better late than never! This is exactly what I wanted ... I should say exactly what I ASKED FOR. Now that I've started to use it I realize that I would love even more if I could specify the pixel coordinates (relative to top left) that I want in the frame. I'm using Paint/GIMP, I put the cursor at the top left corner of the section I want to keep and record the position it reports. Then I do the same for the bottom right corner. Ideally I could use those numbers directly rather than use them to generate the inputs to your awesome script. Is it too much to ask for a revision? :D — Stainsor, Aug 30 '11 at 13:07
Oh, is it possible to write a script that runs this script repeatedly for several files? Something like: (script-fu-wirebear-edger "C:\\1.png" "C:\\1e.png" 1 2 3 4) (script-fu-wirebear-edger "C:\\2.png" "C:\\2e.png" 1 2 3 4) (script-fu-wirebear-edger "C:\\3.png" "C:\\3e.png" 1 2 3 4) — Stainsor, Aug 30 '11 at 13:18
@Stainsor I have added a Batch Edger script above that will allow you to run the script on a folder full of images. As for your first request about specifying the pixel coordinates, I'm not sure I understand exactly what you are looking for. — theChrisKent, Aug 31 '11 at 14:40

score 4 · Answer 2 · answered Apr 27 '11 at 23:02

4

Gimp is not the right tool for the job. Install imagemagick or graphicsmagick. It contains convert binary.

See here: http://www.imagemagick.org/Usage/crop/#crop_repage

answered Apr 27 '11 at 23:02

ypnos

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Thanks. That looks like it will do the job. – Stainsor Apr 28 '11 at 13:07
I tried finding something other than the `-crop` option that you linked to since I want to specify the number of pixels to shave off each side rather than the size of the remaining image. But it looks like `-crop` is the best option after all: `convert test.png -crop 300x200+232+93 +repage test_crop.png` ... I only have a couple different image sizes anyway. Thanks again! – Stainsor Apr 28 '11 at 13:35
What you want is shave and chop commands, on the same page: http://www.imagemagick.org/Usage/crop/#shave | http://www.imagemagick.org/Usage/crop/#chop [unfortunately Imagemagick documentation is not very well organized] – ypnos Apr 28 '11 at 21:18

How do I write a custom auto-crop script using the GIMP?

2 Answers2

Edger Script

Batch Edger Script