Using .map file as a raster layer source

[Frank Warmerdam]

On 8/25/05, Tamas Szekeres <szekeres.tamas at freemail.hu> wrote:
> Frank,
> 
> Could the use of msImageCopyMerge or the generalization of msDrawMap (that
> accepts the initial image as a parameter) solve problem you have mentioned?

Tamas, 

I think that msImageCopyMerge() will handle all combinations of GD
images (8, 24 and 32bit) but it won't handle other types of imageObj,
such as raw 8, 16 or 32bit images or the various funky formats like
SWF, pdf, etc.  Some of them don't make sense.  So my suggestion
would be to for you to verify that the imageObj is GD based, and
if not error out.  If it is, you can likely use msImageCopyMerge(). 
For mixed types (one 8bit, one RGB) it will just use gdImageCopyMerge.
You might need to look into that to see if it handles mismatched types
properly.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent