pnmpad
Add padding to PNM images
TLDR
Add padding to image
$ pnmpad -left [10] -right [10] [input.pnm] > [output.pnm]
Add uniform padding$ pnmpad -width [100] -height [100] [input.pnm] > [output.pnm]
Pad with specific color$ pnmpad -color [white] -left [5] [input.pnm] > [output.pnm]
SYNOPSIS
pnmpad [options] [file]
DESCRIPTION
pnmpad adds padding (blank space) around PNM images, extending the canvas size without scaling the original content. Padding can be added independently to each side using -left, -right, -top, and -bottom.Alternatively, -width and -height specify the desired output dimensions, with -halign and -valign controlling alignment within the padded canvas (default is centered). The -color option sets the padding color (default is black). The -mwidth and -mheight options pad to a multiple of a given pixel count. This is the inverse of pnmcrop. Part of the Netpbm toolkit.
PARAMETERS
FILE
Input PNM file.-left N
Pixels to add on left.-right N
Pixels to add on right.-top N
Pixels to add on top.-bottom N
Pixels to add on bottom.-width N
Target width (centered).-height N
Target height (centered).-color COLOR
Padding color (default: black).-white
Pad with white (shortcut).-halign RATIO
Horizontal alignment ratio (0.0=left, 0.5=center, 1.0=right).-valign RATIO
Vertical alignment ratio (0.0=bottom, 0.5=center, 1.0=top).-mwidth N
Pad width to a multiple of N pixels.-mheight N
Pad height to a multiple of N pixels.-extend-edge
Pad by duplicating adjacent edge pixels.-detect-background
Detect and use image background color for padding.-reportonly
Print padding description instead of producing output.
CAVEATS
Opposite of pnmcrop. Part of Netpbm suite. The -extend-edge and -detect-background options require Netpbm 11.05 or later.
