Importing / rectifying a pdf map - rectangle appears as rhomboid
hover
Global Mapper UserTrusted User
I try to import this map: map-02Apr2014-2103.pdf, choosing the "manually rectify" option when prompted.
As projection I select Swiss Grid CH03, a projection with a base of 600000 / 200000.
In the zoom view, I then designate two reference points,
- Point 1: 608900 / 198300
- Point 2: 608850 / 198400
Both points are marked with a crosshair, as expected.
After importing, the rectangle "2292" on the map appears skewed (as a rhomboid) and the north indocator (on the map) doesn't point upwards.
What am I doing wrong?
I would have expected the map appearing rectified and rotated, in Global Mapper.
As projection I select Swiss Grid CH03, a projection with a base of 600000 / 200000.
In the zoom view, I then designate two reference points,
- Point 1: 608900 / 198300
- Point 2: 608850 / 198400
Both points are marked with a crosshair, as expected.
After importing, the rectangle "2292" on the map appears skewed (as a rhomboid) and the north indocator (on the map) doesn't point upwards.
What am I doing wrong?
I would have expected the map appearing rectified and rotated, in Global Mapper.
Comments
-
Hello Hover,
Add Point 3: 608900 / 198400
Two points are fine when you have a map that is already rotated, with equal x- and y-scales.
Two points do not provide enough information to rotate an image and rectify it.
For example, I used three points to import your map, then exported a JPG file.
When importing the JPG (without separate world or projection file), I need to manually rectify the image.
Using your two points is now sufficient and it overlays the original import nicely.
Mykle -
Hi Mykle
A perfect hint, I really appreciate.
Thanks a lot!
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