Batch removal of coloured background of large pdf

[Ozman]

Your program looks amazing. I am trying to get my head around it atm. Could you provide an example for me so I understand how it works a little better. ATM I need to remove the background of a 480 page scanned pdf using the select by colour tool. The pdf is now converted to xcf format. There are no layers, each page is a separate image. Thanks very much.

[kamilburda]

Hi! First off, thank you 😊

You could be able to do this as follows:

1. Open the PDF in GIMP as separate layers (set Open pages as to Layers rather than Images).
2. Open File -> Export Layers....
3. Add the gegl:color-to-alpha action and adjust the parameters as desired (particularly the color to remove). Note that this will remove the color anywhere in the image, not just around the edges.
4. Adjust other settings in the main dialog (e.g. output folder and file format) and then hit Export.

If you intend to export the pages as a single PDF, set the file format to pdf and go to Options... and set Perform export: to As a single image.

If you have multiple opened images instead, you can apply the same steps via File -> Export Images.... Actually, you don't even have to have the XCFs opened in GIMP and you could also instead use File -> Batch Convert....

[Ozman]

Thank you so much! It worked a treat. 😁