TKIMGGDAL
Extras
The package also adds a few useful standalone Tcl commands:
gdalimg height very_big_image.tif
returns the height or number of rows of the image
gdalimg width very_big_image.tif
returns the width or number of columns of the image
gdalimg bands very_big_image.tif
returns the number of raster bands in the image
gdalcache X
sets the internal cache used by the GDAL library to X MB. This can speed up image access considerably.