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jpeghotp - Online in the Cloud

Run jpeghotp in OnWorks free hosting provider over Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator

This is the command jpeghotp that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator



jpeghotp - find hot or dead pixels in otherwise black or white JPEG images




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

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.


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.

Display version information and exit immediately.

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