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--- doc:appunti:linux:gimp_batch [2022/11/23 17:20] – [The erode filter] niccolo
+++ doc:appunti:linux:gimp_batch [2022/11/23 17:39] (current) – [Call the script from the command line] niccolo
@@ Line 42: / Line 42: @@
     (gimp-image-delete image)))
 </file>
+Copy the script into the **$HOME/.config/GIMP/2.10/scripts/** directory, no particular action is required to enable it.
+===== Call the script from the command line =====
+Now it is possibile to execute the GIMP in batch mode, using the **%%-b%%** option. Calling the custom function ''simple-myerode'' you can pass the paramteres:
+<code bash>
+#!/bin/bash
+gimp -i -b "(simple-myerode \"IMAGE.JPG\" 0 0 0 0 0 0)" -b '(gimp-quit 0)'
+</code>
+===== Combining Imagemagick and GIMP =====
+The final recipe works as follow:
+  * Enlarge the image at 250% with Imagemagick. This proved to be the best choice to enhance the text readability via the erode filter. This is because the erode filter works by adding a single pixel around the dark parts.
+  * Apply the GIMP erode filter.
+  * Use Imagemagick to apply the **%%-unsharp%%** filter. Resize to the original size and crop/resize the image to a fixed size, even if the input image is slightly wider or narrower. Force the resolution to 200 dpi ignoring that of the original image.
+This is the full script, which **receives the filename** to be processed and saves the output file into the **./outdir/** directory:
+<code bash>
+#!/bin/bash
+BASENAME="$(basename "$1")"
+TMP="tmp.$$.png"
+convert "$1" -scale '250%' "$TMP"
+cp -p simple-myerode.scm /home/niccolo/.config/GIMP/2.10/scripts/
+gimp -i -b "(simple-myerode \"$TMP\" 0 0 0 0 0 0)" -b '(gimp-quit 0)'
+convert "$TMP" -unsharp '0x3+1.0+0' \
+    -scale 'x2000' -gravity center -crop '1400:2000' \
+    -background white -extent '1400x2000' -density 200 -units PixelsPerInch \
+    -quality 90 \
+    "./outdir/$BASENAME"
+rm "$TMP"
+</code>