Split a pdf by page, rasterise and downsample each page

convert.py

import os
from subprocess import call

input_pdf = "plotCGHAnnexe.pdf"
for n_p in range(1, 23):
    tgt_file = "plot_%d.pdf" % (n_p)
    cropped_file = os.path.splitext(tgt_file)[0] + "-crop" + ".pdf"
    downsampled = "lq_" + os.path.splitext(cropped_file)[0] + ".pdf"
    midsampled = "hq_" + os.path.splitext(cropped_file)[0] + ".pdf"
    call(args=["pdfjam", "plotCGHAnnexe.pdf", str(n_p), "--outfile", tgt_file])
    call(args=["pdfcrop.pl", "--margins", "20 20 20 20", tgt_file])
    call(args=["convert", "-density", "300", cropped_file, downsampled])
    call(args=["convert", "-density", "450", cropped_file, midsampled])
    print("finished %s", downsampled)