Opened 17 years ago
Closed 16 years ago
#1951 closed defect (fixed)
Lanczos Resample Anomolies near nodata values.
| Reported by: | warmerdam | Owned by: | dron |
|---|---|---|---|
| Priority: | normal | Milestone: | 1.5.2 |
| Component: | Utilities | Version: | svn-trunk |
| Severity: | normal | Keywords: | gdalwarp lanczos |
| Cc: |
Description
Andrey,
When I run the following warps, I see a trough in the pixels values along the left side of the valid data in the lanczos result, but nothing like that in the cubic spline output. I think this is a problem in the lanc resampler but I'm not positive. Could you look into it at some point? Let me know if you need me to more specifically highlight the issue.
gdalwarp warpsamp.tif -tr 500 500 -rcs out.tif -srcnodata -32768 gdalwarp warpsamp.tif -tr 500 500 -r lanczos out.tif -srcnodata -32768
Attachments (1)
Change History (2)
by , 17 years ago
| Attachment: | warpsamp.tif added |
|---|
comment:1 by , 16 years ago
| Milestone: | 1.5.1 → 1.5.2 |
|---|---|
| Resolution: | → fixed |
| Status: | new → closed |
The problem was that dfAccumulatorWeight can be > 1 when we ignore some source nodata values, and the normalization of values and densities was only done when dfAccumulatorWeight < 1.
I think this could also happen in cubic spline resampling so I fixed both.
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input file to demonstrate lanc issue.