Opened 15 years ago
Closed 15 years ago
#2650 closed defect (worksforme)
3rd order GCP fitting
| Reported by: | rjc1 | Owned by: | warmerdam |
|---|---|---|---|
| Priority: | highest | Milestone: | 1.5.4 |
| Component: | default | Version: | 1.5.3 |
| Severity: | normal | Keywords: | 3rd order fitting |
| Cc: |
Description
The documentation says 3rd order GCP fitting is supported. But it produces distorted results. After looking through the GDALCreateGCPTransformer code: if nRequiredOrder is set to 0, the code sets it to 2nd order even though there are 10 or more GCPs. There is also a comment in the source code saying 3rd order is unstable. I downloaded GDAL for a NIST project expecting it to work upto 3rd order. While we are at it 5th order is highly desirable.
Change History (1)
comment:1 by , 15 years ago
| Resolution: | → worksforme |
|---|---|
| Severity: | critical → normal |
| Status: | new → closed |
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I believe it is still possible to create 3rd order polynomial transformers by explicitly passing in 3 as the order. If zero is passed in (automatic) nothing higher than 2 will be used since higher orders are pretty unstable.
If you find it is not possible to pass the order in as 3 (to GDALCreateGenImgProjTransformer()) then please reopen this ticket, indicating details.