From df2ed521c9d341b33e405d63dac6501bcff9b330 Mon Sep 17 00:00:00 2001
From: Borgal <mueller.lars@online.de>
Date: Thu, 18 Jul 2024 14:00:16 +0000
Subject: [PATCH] =?UTF-8?q?paperless/Scripts=20hinzugef=C3=BCgt?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 paperless/scripts/pre-consume.sh        |  5 +++
 paperless/scripts/remove-blank-pages.sh | 49 +++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100755 paperless/scripts/pre-consume.sh
 create mode 100755 paperless/scripts/remove-blank-pages.sh

diff --git a/paperless/scripts/pre-consume.sh b/paperless/scripts/pre-consume.sh
new file mode 100755
index 0000000..1436ab0
--- /dev/null
+++ b/paperless/scripts/pre-consume.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+set -x
+
+# Remove blank pages
+/usr/src/paperless/scripts/remove-blank-pages.sh
\ No newline at end of file
diff --git a/paperless/scripts/remove-blank-pages.sh b/paperless/scripts/remove-blank-pages.sh
new file mode 100755
index 0000000..3c2d05c
--- /dev/null
+++ b/paperless/scripts/remove-blank-pages.sh
@@ -0,0 +1,49 @@
+#!/bin/bash
+#set -x -e -o pipefail
+set -e -o pipefail
+export LC_ALL=C
+
+#IN="$1"
+IN="$DOCUMENT_WORKING_PATH"
+
+# Check for PDF format
+TYPE=$(file -b "$IN")
+
+if [ "${TYPE%%,*}" != "PDF document" ]; then
+  >&2 echo "Skipping $IN - non PDF [$TYPE]."
+  exit 0
+fi
+
+# PDF file - proceed
+
+#PAGES=$(pdfinfo "$IN" | grep ^Pages: | tr -dc '0-9')
+PAGES=$(pdfinfo "$IN" | awk '/Pages:/ {print $2}')
+
+>&2 echo Total pages $PAGES
+
+
+# Threshold for HP scanners
+# THRESHOLD=1
+# Threshold for Lexmar MC2425
+THRESHOLD=0.8
+
+
+non_blank() {
+  for i in $(seq 1 $PAGES) ; do
+    PERCENT=$(gs -o -  -dFirstPage=${i} -dLastPage=${i} -sDEVICE=ink_cov "${IN}" | grep CMYK | nawk 'BEGIN { sum=0; } {sum += $1 + $2 + $3 + $4;} END {  printf "%.5f\n", sum } ')
+    >&2 echo -n "Color-sum in page $i is $PERCENT: "
+    if awk "BEGIN { exit !($PERCENT > $THRESHOLD) }"; then
+      echo $i
+      >&2 echo "Page added to document"
+    else
+      >&2 echo "Page removed from document"
+    fi
+  done
+}
+
+NON_BLANK=$(non_blank)
+
+if [ -n "$NON_BLANK" ]; then
+  NON_BLANK=$(echo $NON_BLANK  | tr ' ' ",")
+  qpdf "$IN" --warning-exit-0 --replace-input --pages . $NON_BLANK --
+fi
\ No newline at end of file