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/