BWSHRINK(1)

NAME

bwshrink - shrink a black and white bw file

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SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
SEE ALSO
BUGS
AUTHOR
COPYRIGHT
BUG REPORTS

SYNOPSIS

bwshrink [-u] [-w _in_width_] [-n _in_height_] [-s _squaresize_] [-f _shrink_factor_] [_infile.bw_] > _outfile.bw_

bwshrink reads a black and white bw(5) format file and produces a scaled-down version. The program reads the entire image into memory and then scales it down to 1/factor of the original size in both dimensions. By default, bwshrink uses boxcar averaging to produce the output pixels.

OPTIONS

-u: Use pixel undersampling (nearest-neighbor decimation) instead of the default boxcar averaging.
-w in_width: Specify the input file width in pixels. The default is 512.
-n in_height: Specify the input file height (number of scanlines) in pixels. The default is 512.
-s squaresize: Set both the input file width and height to the given size in pixels.
-f shrink_factor: Set the integer scaling factor. Must be greater than 1. The default factor is 2.
-h, -?: Print a usage message and exit.

EXAMPLES

Example 1. Shrinking a 1024x1024 image

bwshrink -s 1024 -f 4 image.bw > image_small.bw

Shrinks the 1024x1024 input file image.bw by a factor of 4, producing a 256x256 output file named image_small.bw using boxcar averaging.

Example 2. Generating a thumbnail from a color render

pix-bw -e ntsc -w 2048 -n 1536 render.pix | bwshrink -w 2048 -n 1536 -f 8 -u > thumb.bw

Converts a 2048x1536 color pix(5) render to grayscale with pix-bw(1), then pipes it to bwshrink to produce a 256x192 thumbnail. The -u flag selects fast nearest-neighbor undersampling instead of averaging.