[gdal-dev] 1-bit TIFF Images

[Even Rouault]

Matt,

The TIFF driver also supports writing 1-bit TIFF images. See NBITS in the 
Creation Options section.

For example: gdal_translate source.tif output_1bit.tif -co NBITS=1

When reading a 1-bit TIFF image, GDAL will expand each bit as a byte.
When writting a 1-bit TIFF image, GDAL will write 1 as the bit value if the 
pixel value is non-zero, or 0 as the bit value if the pixel value is zero.

Le Friday 19 December 2008 21:16:53 Matt Klaric, vous avez écrit :
> Does anyone have any experience using 1-bit TIFF images with GDAL?  The
> GeoTIFF file format page (http://www.gdal.org/frmt_gtiff.html) indicates
> that they can be read, but is silent on the issue of writing them.  I'm
> interested in writing them using GDAL, but it appears that the 1-bit data
> type is not valid in GDAL(
> http://gdal.org/gdal_8h.html#22e22ce0a55036a96f652765793fb7a4).  Does
> anyone have any experience with this?  How difficult would it be to modify
> the TIFF driver to handle these?
>
> Thanks,
> Matt Klaric