1 files changed, 42 insertions, 0 deletions
diff --git a/bin/diff-pdf-page.py b/bin/diff-pdf-page.py
new file mode 100755
index 000000000000..153654d5d386
--- /dev/null
+++ b/bin/diff-pdf-page.py
@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# Diffs two PDF pages: a reference and our own output. Red output means some to fix: the amount of
+# red is meant to reduce as fixing progresses. Sample usage:
+#
+# bin/diff-pdf-page.py reference.pdf test.pdf diff.png
+
+import argparse
+import tempfile
+import subprocess
+
+def run(argv):
+    print(" ".join(argv))
+    subprocess.run(argv, check=True)
+
+def main():
+    parser = argparse.ArgumentParser(description="Diffs two PDF pages, first is painted red instead of black, the second is painted on top of the first.")
+    parser.add_argument("-d", "--density", default="384")
+    parser.add_argument("-p", "--page", default="0")
+    parser.add_argument("a_pdf")
+    parser.add_argument("b_pdf")
+    parser.add_argument("diff_png")
+    args = parser.parse_args()
+
+    a_png = tempfile.NamedTemporaryFile(suffix=".png")
+    a_pdf = args.a_pdf + "[" + args.page + "]"
+    run(["convert", "-density", args.density, a_pdf, "-colorspace", "RGB", "-fuzz", "95%", "-fill", "red", "-opaque", "black", a_png.name])
+    b_png = tempfile.NamedTemporaryFile(suffix=".png")
+    b_pdf = args.b_pdf + "[" + args.page + "]"
+    run(["convert", "-density", args.density, b_pdf, "-colorspace", "RGB", b_png.name])
+    composite_png = tempfile.NamedTemporaryFile(suffix=".png")
+    run(["convert", "-composite", a_png.name, b_png.name, composite_png.name])
+    run(["convert", composite_png.name, "-background", "white", "-flatten", args.diff_png])
+
+if __name__ == "__main__":
+    main()
+
+# vim:set shiftwidth=4 softtabstop=4 expandtab: