thumbnail [ options ] input.tif output.tif
thumbnail is a program written to show how one might use the
SubIFD tag (#330) to store thumbnail images.
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.
- -w width¶
Specify the width of thumbnail images in pixels.
- -h height¶
Specify the height of thumbnail images in pixels.
- -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:
50% exponential curve
60% exponential curve
70% exponential curve
80% exponential curve
90% exponential curve
pure exponential curve
There are no options to control the format of the saved thumbnail images.