[Geotiff] Geotiff problem with "small" images???

[Frank Warmerdam]

Max Martinez wrote:
> If I write the geotiff tags using the correct size then the
> image appears badly distorted when viewed in openev and
> in arcgis. If however I keep everything else the same and
> pretend that the image is 1Km x 1.5Km the image will appear
> undistorted.
> 
> Has anyone come across this issue before, is there some fundamental
> lower limit on the image size that I've not picked up on? Or can someone
> tell me how to search the mailing list archives for similar issues?

Duncan,

As Max suggests this can easily occur if values are converted to floating,
or even in full double precision in some extreme cases.  OpenEV uses 32bit
floats for the OpenGL meshes through which the raster textures are drawn
so it can easily fall into serious precision problems.  I've seen this effect
with images less extreme than yours.

Nothing wrong with your image - it's just the software.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org