NAME
jpeghotp - find hot or dead pixels in otherwise black or white JPEG
images
SYNOPSIS
jpeghotp [OPTION]... JPEG-FILE [PIXEL-BLOCKS-FILE]
DESCRIPTION
Jpeghotp automatically finds hot pixels in an otherwise black JPEG
image (default) or dead pixels in an otherwise white JPEG image (if the
--invert option is specified). The output is suitable as a pixel block
specification file for the jpegpixi(1) program. A typical application
is to process an image taken with a digital camera with CCD defects.
To obtain a black image, take a picture in total darkness or with
covered lens. To obtain a while image, take an overexposed picture of a
well-lit piece of white paper.
JPEG-FILE is the filename of the JPEG image to read. It can be -, which
refers to standard input.
PIXEL-BLOCKS-FILE is the name of the file to write the coordinates and
sizes of the hot (or dead) pixel blocks to. If it is omitted, the
coordinates and sizes are written to standard output.
OPTIONS
-t THRESHOLD, --threshold=THRESHOLD
Specify the threshold between noise and signal. Pixel
luminosities below the threshold are considered CCD noise,
luminosities above are considered hot pixels. THRESHOLD must be
a number between 0 and 100 followed by a percent character (%).
The default is 10%.
-i, --invert
Invert the image. If this option is specified, dead pixels in an
otherwise white image instead of hot pixels in an otherwise
black image are found.
-c, --comments
Output comments with the luminosities of the hot (or dead) pixel
blocks. This can be helpful in hand tuning the pixel blocks
file.
--help Display a short help text and exit immediately.
--version
Display version information and exit immediately.
BUGS
Please report bugs to <martin-jpegpixi@zero-based.org>.
COPYRIGHT
Copyright © 2003, 2004, 2005 Martin Dickopp
Jpeghotp is free software; it may be copied and/or modified under the
terms of the GNU General Public License version 2 or (at your option)
any later version. There is NO warranty; not even for MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO
jpegpixi(1)
The jpegpixi homepage: http://www.zero-based.org/software/jpegpixi/