TIFF input and GIF quality

Stephen Lime steve.lime at dnr.state.mn.us
Tue Nov 21 16:24:46 EST 2000


We've always done pre-processing from 24 to 8 bits. Even with 128 colors LandSat
output is pretty decent. Bi-cubic resampling with colormapped data? Not possible. I
assume your wanting to sample the 24-bit image with the better resampling and then
doing a color reduction. Possible but painfully slow.

Steve

Stephen Lime
Internet Applications Analyst

Minnesota DNR
500 Lafayette Road
St. Paul, MN 55155
651-297-2937

>>> "Marc Jacquin" <jacquin at geosys-inc.com> 11/21/00 03:00PM >>>
Hi folks,

I am facing a quite serious problem. In our market we usually use SPOT or
Landsat images with 3 bands (RGB). Unfortunately the only images supported
by MapServer are 8 bits.

Did somebody worked around that ? It requires to apply dithering (24->8
bits) which is not so obvious but feasible.

Also we encounter quality problems with nearest neighbour resampling,
bi-cubic would be useful.

Thanks,

Marc






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