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thumbnail
=========
.. program:: thumbnail
Synopsis
--------
**thumbnail** [ *options* ] *input.tif* *output.tif*
Description
-----------
:program:`thumbnail` is a program written to show how one might use the
``SubIFD`` tag (#330) to store thumbnail images.
:program:`thumbnail`
copies a TIFF Class F facsimile file to the output file
and for each image an 8-bit greyscale "thumbnail sketch" is created.
The output file contains the thumbnail image with the associated
full-resolution page linked below with the SubIFD tag.
By default, thumbnail images are 216 pixels wide by 274 pixels high.
Pixels are calculated by sampling and filtering the input image
with each pixel value passed through a contrast curve.
Options
-------
.. option:: -w width
Specify the width of thumbnail images in pixels.
.. option:: -h height
Specify the height of thumbnail images in pixels.
.. option:: -c contrast
Specify a contrast curve to apply in generating the thumbnail images.
By default pixels values are passed through a linear contrast curve
that simply maps the pixel value ranges. Alternative curves are:
====== ======================
Curve Description
====== ======================
exp50 50% exponential curve
exp60 60% exponential curve
exp70 70% exponential curve
exp80 80% exponential curve
exp90 90% exponential curve
exp pure exponential curve
linear linear curve
====== ======================
Bugs
----
There are no options to control the format of the saved thumbnail images.
See also
--------
:doc:`tiffdump` (1),
:doc:`tiffgt` (1),
:doc:`tiffinfo` (1),
:doc:`/functions/libtiff` (3tiff),
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