From ac7152950ea9862b51dcac0e5aa7e4f02ca3d942 Mon Sep 17 00:00:00 2001
From: Juri Dispan <juri.dispan@posteo.net>
Date: Tue, 6 Feb 2024 16:43:21 +0100
Subject: [PATCH] pnmhisteq, pnmhistmap, pnmindex, pnminvert: add pages
 (#12189)

* pnmhisteq, pnmhistmap, pnmindex, pnminvert: add pages

* Update pages/common/pnmindex.md

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

---------

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>
---
 pages/common/pnmhisteq.md  | 16 ++++++++++++++++
 pages/common/pnmhistmap.md | 16 ++++++++++++++++
 pages/common/pnmindex.md   | 21 +++++++++++++++++++++
 pages/common/pnminvert.md  |  8 ++++++++
 4 files changed, 61 insertions(+)
 create mode 100644 pages/common/pnmhisteq.md
 create mode 100644 pages/common/pnmhistmap.md
 create mode 100644 pages/common/pnmindex.md
 create mode 100644 pages/common/pnminvert.md

diff --git a/pages/common/pnmhisteq.md b/pages/common/pnmhisteq.md
new file mode 100644
index 000000000..95710ee2f
--- /dev/null
+++ b/pages/common/pnmhisteq.md
@@ -0,0 +1,16 @@
+# pnmhisteq
+
+> Histogram-equalize a PNM image.
+> More information: <https://netpbm.sourceforge.net/doc/pnmhisteq.html>.
+
+- Increase the contrast of a PNM image using histogram equalization:
+
+`pnmhisteq {{path/to/input.pnm}} > {{path/to/output.pnm}}`
+
+- Only modify grey pixels:
+
+`pnmhisteq -grey {{path/to/input.pnm}} > {{path/to/output.pnm}}`
+
+- Do not include black or white pixels in the histogram equalization:
+
+`pnmhisteq -no{{black|white}} {{path/to/input.pnm}} > {{path/to/output.pnm}}`
diff --git a/pages/common/pnmhistmap.md b/pages/common/pnmhistmap.md
new file mode 100644
index 000000000..5b3dc477b
--- /dev/null
+++ b/pages/common/pnmhistmap.md
@@ -0,0 +1,16 @@
+# pnmhistmap
+
+> Draw a histogram of a PNM image.
+> More information: <https://netpbm.sourceforge.net/doc/pnmhistmap.html>.
+
+- Draw a histogram of a PNM image:
+
+`pnmhistmap {{path/to/input.pnm}} > {{path/to/output.pnm}}`
+
+- Draw the histogram as dots instead of bars:
+
+`pnmhistmap -dots {{path/to/input.pnm}} > {{path/to/output.pnm}}`
+
+- Specify the range of intensity values to include:
+
+`pnmhistmap -lval {{minval}} -rval {{maxval}} {{path/to/input.pnm}} > {{path/to/output.pnm}}`
diff --git a/pages/common/pnmindex.md b/pages/common/pnmindex.md
new file mode 100644
index 000000000..4dfbf39f1
--- /dev/null
+++ b/pages/common/pnmindex.md
@@ -0,0 +1,21 @@
+# pnmindex
+
+> Build a visual index of multiple PNM images.
+> See also: `pamundice`.
+> More information: <https://netpbm.sourceforge.net/doc/pnmindex.html>.
+
+- Produce an image containing thumbnails of the specified images in a grid:
+
+`pnmindex {{path/to/input1.pnm path/to/input2.pnm ...}} > {{path/to/output.pnm}}`
+
+- Specify the size of the (quadratic) thumbnails:
+
+`pnmindex -size {{50}} {{path/to/input1.pnm path/to/input2.pnm ...}} > {{path/to/output.pnm}}`
+
+- Specify the number of thumbnails per row:
+
+`pnmindex -across {{10}} {{path/to/input1.pnm path/to/input2.pnm ...}} > {{path/to/output.pnm}}`
+
+- Specify the maximum number of colors in the output:
+
+`pnmindex -colors {{512}} {{path/to/input1.pnm path/to/input2.pnm ...}} > {{path/to/output.pnm}}`
diff --git a/pages/common/pnminvert.md b/pages/common/pnminvert.md
new file mode 100644
index 000000000..c89de8e5a
--- /dev/null
+++ b/pages/common/pnminvert.md
@@ -0,0 +1,8 @@
+# pnminvert
+
+> Invert a PNM image.
+> More information: <https://netpbm.sourceforge.net/doc/pnminvert.html>.
+
+- Invert the colors or greyscale values in a PNM image:
+
+`pnminvert {{path/to/input.pnm}} > {{path/to/output.pnm}}`