pnmmargin, pnmmontage, pnmnlfilt, pnmnorm, pnmpad, pnmpaste: add pages (#12187)

* pnmmargin, pnmmontage, pnmnlfilt, pnmnorm, pnmpad, pnmpaste: add pages

---------

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>
Co-authored-by: Vitor Henrique <87824454+vitorhcl@users.noreply.github.com>

pages/common/pnmmargin.md

@@ -0,0 +1,12 @@
+# pnmmargin
+
+> Add a border to a PNM image.
+> More information: <https://netpbm.sourceforge.net/doc/pnmmargin.html>.
+
+- Add a border of the specified size to a PNM image:
+
+`pnmmargin {{size}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Specify the color of the border:
+
+`pnmmargin -color {{color}} {{size}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`

pages/common/pnmmontage.md

@@ -0,0 +1,20 @@
+# pnmmontage
+
+> Create a montage from multiple PNM images.
+> More information: <https://netpbm.sourceforge.net/doc/pnmmontage.html>.
+
+- Produce a packing of the specified images:
+
+`pnmmontage {{path/to/image1.pnm path/to/image2.pnm ...}} > {{path/to/output.pnm}}`
+
+- Specify the quality of the packing (Note: larger values produce smaller packings but take longer to compute.):
+
+`pnmmontage -{{0..9}} {{path/to/image1.pnm path/to/image2.pnm ...}} > {{path/to/output.pnm}}`
+
+- Produce a packing that is not larger than `p` percent of the optimal packing:
+
+`pnmmontage -quality {{p}} {{path/to/image1.pnm path/to/image2.pnm ...}} > {{path/to/output.pnm}}`
+
+- Write the positions of the input files within the packed image to a machine-readable file:
+
+`pnmmontage -data {{path/to/datafile}} {{path/to/image1.pnm path/to/image2.pnm ...}} > {{path/to/output.pnm}}`

pages/common/pnmnlfilt.md

@@ -0,0 +1,16 @@
+# pnmnlfilt
+
+> Apply a non-linear filter onto a PNM image.
+> More information: <https://netpbm.sourceforge.net/doc/pnmnlfilt.html>.
+
+- Apply the "alpha trimmed mean" filter with the specified alpha and radius values onto the PNM image:
+
+`pnmnlfilt {{0.0..0.5}} {{radius}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Apply the "optimal estimation smoothing" filter with the specified noise threshold and radius onto the PNM image:
+
+`pnmnlfilt {{1.0..2.0}} {{radius}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Apply the "edge enhancement" filter with the specified alpha and radius onto the PNM image:
+
+`pnmnlfilt {{-0.9..(-0.1)}} {{radius}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`

pages/common/pnmnorm.md

@@ -0,0 +1,21 @@
+# pnmnorm
+
+> Normalize the contrast in a PNM image.
+> See also: `pnmhisteq`.
+> More information: <https://netpbm.sourceforge.net/doc/pnmnorm.html>.
+
+- Force the brightest pixels to be white, the darkest pixels to be black and spread out the ones in between linearly:
+
+`pnmnorm {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Force the brightest pixels to be white, the darkest pixels to be black and spread out the ones in between quadratically such that pixels with a brightness of `n` become 50 % bright:
+
+`pnmnorm -midvalue {{n}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Keep the pixels' hue, only modify the brightness:
+
+`pnmnorm -keephues {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Specify a method to calculate a pixel's brightness:
+
+`pnmnorm -{{luminosity|colorvalue|saturation}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`

pages/common/pnmpad.md

@@ -0,0 +1,21 @@
+# pnmpad
+
+> Add borders to a PNM image.
+> See also: `pnmmargin`, `pamcut`, `pamcomp`.
+> More information: <https://netpbm.sourceforge.net/doc/pnmpad.html>.
+
+- Add borders of the specified sizes to the image:
+
+`pnmpad -left {{100}} -right {{150}} -top {{123}} -bottom {{456}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Pad the image to the specified size:
+
+`pnmpad -width {{1000}} -height {{500}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Pad the width of the image to the specified size, controlling the ratio between right and left padding:
+
+`pnmpad -width {{1000}} -halign {{0.7}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Pad the width of the image using the specified color:
+
+`pnmpad -width {{1000}} -color {{red}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`

pages/common/pnmpaste.md

@@ -0,0 +1,16 @@
+# pnmpaste
+
+> Paste a PNM image into another PNM image.
+> More information: <https://netpbm.sourceforge.net/doc/pnmpaste.html>.
+
+- Paste a PNM image into another PNM image at the specified coordinates:
+
+`pnmpaste {{x}} {{y}} {{path/to/image1.pnm}} {{path/to/image2.pnm}} > {{path/to/output.pnm}}`
+
+- Paste the image read from `stdin` into the specified image:
+
+`{{command}} | pnmpaste {{x}} {{y}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Combine the overlapping pixels by the specified boolean operation, where white pixels represent `true` while black pixels represent `false`:
+
+`pnmpaste -{{and|nand|or|nor|xor|xnor}} {{x}} {{y}} {{path/to/image1.pnm}} {{path/to/image2.pnm}} > {{path/to/output.pnm}}`