From 101c47872e58c8661c58134304faf03f4546d18a Mon Sep 17 00:00:00 2001
From: Georgy Litvinov <git@litvinovg.pro>
Date: Fri, 8 Jan 2021 19:53:21 +0100
Subject: [PATCH] Added pdf conversion scripts

---
 HackRGB-cmyk-inv.ps | 48 +++++++++++++++++++++++++++++++++++++++++++++
 pdf2flattened.sh    | 11 +++++++++++
 rgb2cmyk.sh         | 18 +++++++++++++++++
 rgb2grey-fonts.sh   | 13 ++++++++++++
 rgb2grey.sh         | 14 +++++++++++++
 5 files changed, 104 insertions(+)
 create mode 100644 HackRGB-cmyk-inv.ps
 create mode 100755 pdf2flattened.sh
 create mode 100755 rgb2cmyk.sh
 create mode 100755 rgb2grey-fonts.sh
 create mode 100755 rgb2grey.sh

diff --git a/HackRGB-cmyk-inv.ps b/HackRGB-cmyk-inv.ps
new file mode 100644
index 0000000..478d3b9
--- /dev/null
+++ b/HackRGB-cmyk-inv.ps
@@ -0,0 +1,48 @@
+%!
+/oldsetrgbcolor /setrgbcolor load def
+/setrgbcolor {
+(in replacement setrgbcolor\n) print
+                                %% R G B
+  1 index 1 index       %% R G B G B
+  eq {                  %%
+     2 index 1 index    %% R G B R B
+     eq {
+                        %% Here if R = G = B
+      pop pop           %% remove two values
+      % setgray % "replace the 'setgray' with":
+      0 0 0 4 -1 roll % setcmykcolor
+      -1 mul          %% obtain -R on top of stack
+      1 add           %% obtain 1-R on top of stack
+      setcmykcolor    %% now set(cmykcolor) K (as 1-R)
+     } {
+       oldsetrgbcolor   %% set the RGB values
+     } ifelse
+  }{
+    oldsetrgbcolor      %% Set the RGB values
+  }ifelse
+
+} bind def
+/oldsetgray /setgray load def
+/setgray {
+(in replacement setgray\n) print
+  % == % debug: pop last element and print it
+  % here we're at a gray value;
+  % http://www.tailrecursive.org/postscript/operators.html#setcymkcolor
+  % setgray: "gray-value must be a number from 0 (black) to 1 (white)."
+  % setcymkcolor: "The components must be between 0 (none) to 1 (full)."
+  % so convert here again:
+  0 0 0 4 -1 roll % push CMY:000 after Gray and roll down,
+                  % so top of stack becomes
+                  % ...:C:M:Y:Gray
+  -1 mul          %% obtain -Gray on top of stack
+  1 add           %% obtain 1-Gray on top of stack
+  setcmykcolor    %% now set(cmykcolor) K (as 1-Gray)
+} bind def
+
+
+%~ # test: rgb2gray
+%~ gs -dNOPAUSE -dBATCH -sDEVICE=ps2write -sOutputFile=./blah-slide-hackRGB-gray.ps ./HackRGB.ps ./blah-slide-gsps2w.ps
+%~ # gray2cmyk
+%~ gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=./blah-slide-hackRGB-gray-ci.pdf ./HackRGB-cmyk-inv.ps ./blah-slide-hackRGB-gray.ps
+%~ # check separations - looks OK
+%~ gs -sDEVICE=tiffsep -dNOPAUSE -dBATCH -dSAFER -dFirstPage=1 -dLastPage=1 -sOutputFile=p%02d.tif blah-slide-hackRGB-gray-ci.pdf && eog p01.tif 2>/dev/null
diff --git a/pdf2flattened.sh b/pdf2flattened.sh
new file mode 100755
index 0000000..65d4cc2
--- /dev/null
+++ b/pdf2flattened.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+name=$1
+gs \
+  -sDEVICE=pdfwrite \
+  -sProcessColorModel=DeviceCMYK \
+  -sColorImageResolution=1200 \
+  -sColorImageFilter=/FlatEncode \
+  -dOverrideICC \
+  -o "$name-flattened.pdf" \
+  "$name"
+
diff --git a/rgb2cmyk.sh b/rgb2cmyk.sh
new file mode 100755
index 0000000..e4ea2cc
--- /dev/null
+++ b/rgb2cmyk.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+name=$1
+pdftops -level3sep "$name" "$name.ps"
+# PS to PDF using replacement function in HackRGB-cmyk-inv.ps
+gs \
+   -dNOPAUSE \
+   -dBATCH \
+   -sDEVICE=pdfwrite \
+   -sColorConversionStrategy=CMYK \
+   -dProcessColorModel=/DeviceCMYK \
+   -dCompatibilityLevel=1.4 \
+   -dAutoRotatePages=/None \
+   -dOverrideICC \
+   -dNoOutputFonts \
+   -sOutputFile="$name-cmyk.pdf" \
+    ~/bin/HackRGB-cmyk-inv.ps \
+    "$name.ps"
+rm -f "$name.ps"
diff --git a/rgb2grey-fonts.sh b/rgb2grey-fonts.sh
new file mode 100755
index 0000000..e8594ed
--- /dev/null
+++ b/rgb2grey-fonts.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+name=$1
+gs \
+  -sDEVICE=pdfwrite \
+  -sProcessColorModel=DeviceGray \
+  -sColorConversionStrategy=Gray \
+  -sColorImageResolution=600 \
+  -sColorImageFilter=/FlatEncode \
+  -dOverrideICC \
+  -dCompatibilityLevel=1.4 \
+  -dAutoRotatePages=/None \
+  -o "$name-grey.pdf" \
+  "$name"
diff --git a/rgb2grey.sh b/rgb2grey.sh
new file mode 100755
index 0000000..c45725f
--- /dev/null
+++ b/rgb2grey.sh
@@ -0,0 +1,14 @@
+#!/bin/bash
+name=$1
+gs \
+  -sDEVICE=pdfwrite \
+  -sProcessColorModel=DeviceGray \
+  -sColorConversionStrategy=Gray \
+  -sColorImageResolution=600 \
+  -sColorImageFilter=/FlatEncode \
+  -dOverrideICC \
+  -dCompatibilityLevel=1.4 \
+  -dAutoRotatePages=/None \
+  -dNoOutputFonts \
+  -o "$name-grey.pdf" \
+  "$name"