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/