[Gdal-dev] BMP to GeoTiff
kamal_jo at yahoo.com
Sun Mar 16 03:03:58 EST 2003
If I want to convert a "bmp" to a "GeoTiff" using
GDAL, can the source "bmp" be a buffer in memory or
does it have to be a bmp file on the disk?
If it can be a buffer what function(s) neede?
--- Frank Warmerdam <warmerdam at pobox.com> wrote:
> Ayman Kamal wrote:
> > 1.
> > You mentioned that
> > adfGeoTransform = /* top left x */
> > adfGeoTransform = /* top left y */
> > -Does top left x mean the value of longitude for
> > left corner?
> > -Does top left y mean the value of lattitude for
> > left corner?
> Yes, if the coordinate system of the image is
> > 2.
> > What does horizental, vertical pixel size mean?
> The width of a pixel is the coordinate system being
> > 3.
> > Are adfGeoTransform,adfGeoTransform always
> No. If the image is not "north up", that is the
> image is
> rotated or sheared from the normal map orientation
> these will
> be non-zero and then the interpretation of the pixel
> size is
> more complicated.
> In common use these values will be zero.
> > 4.
> > If the user doesn't give me any of these data, and
> > still wants me to generate a GeoTiff file out of
> > faces' images for example,
> > are there default values that I can supply to
> > a valid GeoTiff file?
> It is pointless to create a "Geo" TIFF file without
> knowing anything
> about a meaningful coordinate system. If you feel
> the need to do so pick
> any random values you feel like.
> Best regards,
> I set the clouds in motion - turn up | Frank
> Warmerdam, warmerdam at pobox.com
> light and sound - activate the windows |
> and watch the world go round - Rush | Geospatial
> Programmer for Rent
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