This is the command pnmshear that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
NAME
pnmshear - shear a portable anymap by some angle
SYNOPSIS
pnmshear [-noantialias] angle [pnmfile]
DESCRIPTION
Reads a portable anymap as input. Shears it by the specified angle and produces a
portable anymap as output. If the input file is in color, the output will be too,
otherwise it will be grayscale. The angle is in degrees (floating point), and measures
this:
+-------+ +-------+
| | |\ \
| OLD | | \ NEW \
| | |an\ \
+-------+ |gle+-------+
If the angle is negative, it shears the other way:
+-------+ |-an+-------+
| | |gl/ /
| OLD | |e/ NEW /
| | |/ /
+-------+ +-------+
The angle should not get too close to 90 or -90, or the resulting anymap will be
unreasonably wide.
The shearing is implemented by looping over the source pixels and distributing fractions
to each of the destination pixels. This has an "anti-aliasing" effect - it avoids jagged
edges and similar artifacts. However, it also means that the original colors or gray
levels in the image are modified. If you need to keep precisely the same set of colors,
you can use the -noantialias flag. This does the shearing by moving pixels without
changing their values. If you want anti-aliasing and don't care about the precise colors,
but still need a limited *number* of colors, you can run the result through ppmquant.
All flags can be abbreviated to their shortest unique prefix.
Use pnmshear online using onworks.net services
