Hi,

I am working on a project of digitisation of documents in an archive. I am a beginner, I failed in an attempt to code a script to automate the process of cropping and saving an image file with Gimp --leaving a margin around the document image.

In other words, the desired automation would be, step by step:

1. Create a rectangular selection around the document image following the previously established guides.



2. Increase this initial selection in x number of pixels to leave a margin around the document. I achieved to code an easy script for this particular task (in its code you can modify the margin changing the value 50 on the command steps). I copy the code of this script below this message.
3. Crop the selection.
4. Export the obtained image as a TIFF file format without any compression. Overwrite the existing file.


Many thanks for any help.



**margins.py**

#!/usr/bin/env python

from gimpfu import *

def margins(image, drawable):
#Inici de grup de funcions
pdb.gimp_image_undo_group_start(image)
#Afegeix-hi un marge de 0.6 cm, i.e. 71 pixels si dpi=300
steps = 50
pdb.gimp_selection_grow(image, steps)
#Costats no arrodonits
value = 0.0
toggle = 0
pdb.script_fu_selection_rounded_rectangle(image, drawable, value, toggle)
#Final de grup de funcions
pdb.gimp_image_undo_group_end(image)

register(
"python-fu-margins",
"Afegeix un marge a tot el volt de la imatge",
"Afegeix-hi un marge en pixels al comandament steps",
"", "", "2021",
"Margins",
"*",
[
(PF_IMAGE, "image", "takes current image", None),
(PF_DRAWABLE, "drawable", "Input layer", None)
],
[],
margins, menu="<Image>/Select")

main()

IMHO you should better set options for the Crop tools (fixed size, and related values for instance). Then within a given Gimp session you re-use the same options (these options are carried from one image to the next, unlike guides). You can also save the options to re-user them in a future Gimp sessions, either as saving them as specific tool options with a name, or as default tool options.

Also, when handling many files, the most time consuming-part is opening files. I have an `ofn-file-next` script that saves the current image and opens the next in the same directory that is designed to improve this.

You should look into ImageMagick/GraphicsMagick. A command line tool(s) that can do image manipulations. As i recall it can crop images based on color thresholds. It may be more suitable for your project.

Yes, I remember that my first attempt months ago to make this work faster was to test the autocrop with ImageMagick based on color thresholds, but the obtained results were a bit inaccurate (for the digital preservation of unbound manuscripts our goal is to leave at least an 1/4-inch margin, as established by The Library of Congress in: Technical Standards for Digital Conversion of Texts and Graphic Materials, "2.4.1. Cropping. Cropping of bound and manuscript materials", page 15). Anyway, thanks AdmFubar for your suggestion.

On the other hand, in our case I think it's not possible to work with a prefixed values on the crop tool, because it's about an archive where almost each piece of paper has a particular form and size (the producer of that archive was a poet without means to purchase paper amid the Franco's dictatorship, so he used any leaf he found to write his work). Anyway, thanks Ofnuts for your proposal. Actually, for the rare cases such as the example illustrated in my previous message (so the example was no good, in this project the unbound leaves are the most common documents), I use prefixed guides thanks to the script GIMP_save_load_guides.py created by Tin Tran.

Also, I tested your script ofn-file-next.py, but it produces an error: I applied it on a first file (DIG_A-MMI-03551_0001_r.tif) of a folder that contains the files DIG_A-MMI-03551_0001_r.tif, DIG_A-MMI-03551_0002_r.tif, DIG_A-MMI-03551_0002_v.tif, DIG_A-MMI-03551_0003_r.tif, and so on. The script saves the current file correctly (DIG_A-MMI-03551_0001_r.tif), but it can't quit the file and appears the following message in the Error Console:

My suggestion is to use two script-fu (required to run - are added in appendix and updated for Gimp-2.10):
1. Export Sequential_processing.scm by Rob Antonishen viewtopic.php?f=9&t=4846&start=0&hilit=Sequential_processing
2. Guides-to-selection-mk2.scm by SteveMi viewtopic.php?f=9&t=14565&hilit=guides+to+selection&start=20#p201330

As many as 8 lines of code came out of it.
Test it on a small batch copy and let me know if it is right for You.

What is the full path to the directory that contains the files?

Sorry for the delay, these days I am sick. I will answer the other pending questions when I will get better.

Ofnuts, the full path of the directory that contains the files in my testing is: F:/a.mmi/cc/

The disk storage shown as F: is an external hard drive. Thanks.

Many many thanks MareroQ!

Finally this week I could analyse your plugin, as a beginner I learned a bit more about some aspects that I didn't know about the plugins of Gimp thanks to your work.

The encoding declaration #-*- coding:utf-8 -*- in the second line of the plugin, that enables the use of words in Catalan language, is a true gift for me. I had the problem that the plugins didn't run for example if I introduced comment lines in Catalan, and I didn't know any way to do it.

This week I rewrote the plugin to adapt it better to the needs of the digitisation project where I am working for: as I always apply the same margin before cropping an image, I prefer to set the number of margin pixels in the code. On the other hand, I have chosen the plugin save-export-clean.py created by Akkana Peck as an alternative way of exporting the file.

marginscropwrite.py



1. The first step is open many files at once. I.e.: File > Open... and select many files in the Open Image window (with the Single-Window Mode of Gimp enabled).

2. Select the limits of the document with the Rectangle Select Tool and then convert the selection into guides with the option Image > Guides > New Guides from Selection. To automate the next step of removing the rectangular selection, you can substitute the standard option New Guides from Selection for an easy plugin to make containing the procedures pdb.script_fu_guides_from_selection(image, drawable) and pdb.gimp_selection_none(image)

3. Move the four guides to adjust them to the limits of the document thanks to the zoom of Gimp.



4. Execute the plugin marginscropwrite.py (a) to apply a margin of 20 pixels to the previous selection, (b) crop the image to this margin (c) and overwrite the file. You can execute the installed plugin marginscropwrite.py in: Image > Crop to Selection with a Margin and Overwrite

I'm glad you managed to personally customize the plug to your needs.