From 0638b8d95da26503c4ca64de2d36c951fec74d55 Mon Sep 17 00:00:00 2001
From: Juri Dispan <juri.dispan@posteo.net>
Date: Sat, 4 Nov 2023 15:17:59 +0100
Subject: [PATCH] pamdepth, ppmdither, pamditherbw, pnmdepth: add pages
 (#11379)

* pamdepth, pamdither, pamditherbw: add pages

* pnmdepth: add alias page
---
 pages/common/pamdepth.md    |  8 ++++++++
 pages/common/pamditherbw.md | 20 ++++++++++++++++++++
 pages/common/pnmdepth.md    |  8 ++++++++
 pages/common/ppmdither.md   | 16 ++++++++++++++++
 4 files changed, 52 insertions(+)
 create mode 100644 pages/common/pamdepth.md
 create mode 100644 pages/common/pamditherbw.md
 create mode 100644 pages/common/pnmdepth.md
 create mode 100644 pages/common/ppmdither.md

diff --git a/pages/common/pamdepth.md b/pages/common/pamdepth.md
new file mode 100644
index 000000000..f9cea141a
--- /dev/null
+++ b/pages/common/pamdepth.md
@@ -0,0 +1,8 @@
+# pamdepth
+
+> Reduce the depth (i.e. color resolution) in an image.
+> More information: <https://netpbm.sourceforge.net/doc/pamdepth.html>.
+
+- Read a PBM image, set its maxval and save it to a file:
+
+`pamdepth {{maxval}} {{path/to/image.pbm}} > {{path/to/file.pbm}}`
diff --git a/pages/common/pamditherbw.md b/pages/common/pamditherbw.md
new file mode 100644
index 000000000..3ca2482ef
--- /dev/null
+++ b/pages/common/pamditherbw.md
@@ -0,0 +1,20 @@
+# pamditherbw
+
+> Apply dithering to a greyscale image, i.e. turn it into a pattern of black and white pixels that look the same as the original greyscale.
+> More information: <https://netpbm.sourceforge.net/doc/pamditherbw.html>.
+
+- Read a PGM image, apply dithering and save it to a file:
+
+`ppmditherbw {{path/to/image.pgm}} > {{path/to/file.pgm}}`
+
+- Use the specified quantization method:
+
+`ppmditherbw -{{floyd|fs|atkinson|threshold|hilbert|...}} {{path/to/image.pgm}} > {{path/to/file.pgm}}`
+
+- Use the atkinson quantization method and the specified seed for a pseudo-random number generator:
+
+`ppmditherbw -atkinson -randomseed {{1337}} {{path/to/image.pgm}} > {{path/to/file.pgm}}`
+
+- Specify the thresholding value for quantization methods that perform some sort of thresholding:
+
+`ppmditherbw -{{fs|atkinson|thresholding}} -value {{0.3}} {{path/to/image.pgm}} > {{path/to/file.pgm}}`
diff --git a/pages/common/pnmdepth.md b/pages/common/pnmdepth.md
new file mode 100644
index 000000000..ed0252abb
--- /dev/null
+++ b/pages/common/pnmdepth.md
@@ -0,0 +1,8 @@
+# pnmdepth
+
+> This command is an alias of `pamdepth`.
+> More information: <https://netpbm.sourceforge.net/doc/pnmdepth.html>.
+
+- View documentation for the original command:
+
+`tldr pamdepth`
diff --git a/pages/common/ppmdither.md b/pages/common/ppmdither.md
new file mode 100644
index 000000000..5efdf4000
--- /dev/null
+++ b/pages/common/ppmdither.md
@@ -0,0 +1,16 @@
+# ppmdither
+
+> Reduce the number of colors in an image by applying dithering.
+> More information: <https://netpbm.sourceforge.net/doc/ppmdither.html>.
+
+- Read a PPM image, apply dithering and save it to a file:
+
+`ppmdither {{path/to/image.ppm}} > {{path/to/file.ppm}}`
+
+- Specify the desired number of shades for each primary color:
+
+`ppmdither -red {{2}} -green {{3}} -blue {{2}} {{path/to/image.ppm}} > {{path/to/file.ppm}}`
+
+- Specify the dimensions of the dithering matrix:
+
+`ppmdither -dim {{2}} {{path/to/image.ppm}} > {{path/to/file.ppm}}`