[Xastir] what format to export MrSID for xastir use?

[Curt, WE7U]

On Fri, 28 Jan 2005, Tom Russo wrote:

>   Image Width: 6452 Image Length: 7618
>   Bits/Sample: 8
>   Compression Scheme: None
>   Photometric Interpretation: min-is-black
>   Samples/Pixel: 1
>   Rows/Strip: 1
>   Planar Configuration: single image plane
>
>  > gdalinfo 34106H31.tif
> PROJCS["NAD83 / UTM zone 13N",
>     GEOGCS["NAD83",
>         DATUM["North_American_Datum_1983",
>             SPHEROID["GRS 1980",6378137,298.2572221010002,

Hey, that looks like they exactly duplicated the USGS DRG
parameters.  Just with quick look at it that's what I see anyway.
Same projection and everything.


> They work fine, and seem to benefit from the DRG speedups.  I do see,
> though, that the file size balloons from 2.7Mb in MrSID format to
> almost 50MB in GeoTIFF --- even if I enable packbits compression.
> Pity, that.

As much as I despise proprietary compression schemes such as MrSID
(they make publicly-available and free data less publicly available
due to locking the data into proprietary formats), I think there's a
way to use MrSID from inside GDAL, or we could try to use their
development kit directly without GDAL.  The raster portion of our
GDAL integration isn't finished yet, so it might take a while to get
there.

I'd rather get the state/gov't sites to provide non-MrSID, more open
format data, but they're all led to the dark side by the extreme
compression of MrSID.  It'd be a losing battle to just say no to
MrSID.

--
Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
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