[GRASSLIST:1260] Re: TIFF Question

[Eric G . Miller]

On Wed, Dec 13, 2000 at 01:11:07PM +0100, m.malicky at landesmuseum-linz.ac.at wrote:
> Hi all!
> 
> I have the following question/problem!
> 
> I have a vector data layer in tmerc form, with 1m units and a tiff 
> picture where I know the correct offset within the tmerc, with a pixle 
> size corresponding 50m x 50m. How can I put this two layers 
> together?

You can import the tiff into an x-y location and use i.vpoints to
specify tie points for one of the i.rectify commands.

Or, if you know the coordinates of the center of the upper left pixel
for the tiff, and its horizontal and vertical scale factors (50 x 50 ?),
you can create a TIFF World file which the r.in.tiff in beta10 (or
r.in.arctiff in earlier versions) should be able to use to place the
image correctly.

<image>.tfw:
X-Scale           // 50.00000000
X-Shift           //  0.00000000
Y-Shift           //  0.00000000
Y-Scale           // -50.0000000  -- Note the negative!
X-Origin          // Easting of center of pixel (0,0)
Y-Origin          // Northing of center of pixel (0,0)

-- 
Eric G. Miller <egm2 at jps.net>