Akari (2011-12-31)

Image downsampling utility.


   ./akari <input> <output> [even]

Downsamples "input" to "output".  If input is "-" or not specified,
it will be read from stdin.  If output is "-" or not specified, it
will be written to stdout.  Downsampling works by keeping odd pixels
on odd scanlines.  By specifying the third command line argument,
Akari will keep even pixels on even scanlines instead.

Accepted input formats are PPM, PGM, or plain text file with LF end of
line characters.

The source code can be downsampled to create a second utility:

   ./akari akari.c akari2.c
   gcc akari2.c -o akari2

This second program expands stdin to stdout by default, applying a
rot13 filter if an extra argument is specified.  The two programs can
be combined to make a regular rot13 filter:

   cat input.txt | ./akari2 rot13 | ./akari > output.txt

Template is based on Akaza Akari from Yuruyuri.