[PYTHON] Convert PDF files to PNG files with GIMP

Information provided by ministries and agencies related to COVID-19 has many pdf files, and when sharing information, it is difficult to manually convert it to an image in order to visualize a large number of pages, so I created a plug-in.

Share the information below.

1. 1. About GIMP

GIMP is a free and open source image editing software. https://www.gimp.org/

2. How to convert PDF to PNG with GIMP

〇 When manually converting from pdf to png (1) Start GIMP.

(2) Drag and drop the pdf file to display the dialog. Click [Import]. (You can also open it by selecting [File]-[Open / Import])

The pdf will be read as an image. Each page is loaded as a layer.

(3) Export with the extension png from [File]-[Export As ...]. Only the image at the top of the layer is exported here. Repeat this each time, hiding the layer.

〇 When automatically converting from pdf to png (1) First, check if the python plugin is available. https://docs.gimp.org/2.10/ja/gimp-filters-python-fu.html This is also for reference. https://www.ibm.com/developerworks/jp/opensource/library/os-autogimp/index.html

You can use it if you have [Python-Fu] in [Filter]. If not, please do your best. (I'm sorry. Maybe something to do at the time of installation. I was on my own.)

(2) Write the code and save it in the plugin folder.

export_pdf2png.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#

from gimpfu import *
import os

def export_pdf2png(img, drw, path):
    img = img.duplicate()
    for layer in img.layers:
        layer.visible = False
    
    for idx, layer in enumerate(img.layers):
        layer.visible = True
        
        filename = '{0}{1}.png'.format('PDF2PNG', idx)
        fullpath = os.path.join(path, filename)

        layer_img = img.duplicate()
        layer_img.flatten()
        
        pdb.file_png_save(img, img.layers[idx], fullpath, filename, 0, 9, 0, 0, 0, 0, 0)

register(
    "python-fu-export-pdf2png",
    "Export PDF to PNG",
    "Exports pdf to png file",
    "J",
    "",
    "",
    "Convert from PDF to PNG...",
    "*",
    [
        (PF_IMAGE, "img", "Input image", None),
        (PF_DRAWABLE, "drw", "Input drawable", None),
        (PF_DIRNAME, "path", "Output directory", os.getcwd())
    ],
    [],
    export_pdf2png,
    menu="<Image>/File/"
    )

main()

The plugin folder is set to [Edit]-[Settings]-[Folder]-[Plugins].

(3) Restart GIMP and check that it is registered in the [File] menu.

Import the pdf file with GIMP as you would manually.

Select [Convert PDF to PNG ...] from the [File] menu, specify the output destination folder, and execute.

Pages are output like this.

This is the output image (1st page).

I think that it may not work in the environment etc., so I'm sorry in that case. I hope it will be helpful for those in need.

Note: When you start the procedure browser from Help, the procedure information is displayed.