Opened 8 years ago

Closed 5 years ago

#6583 closed defect (wontfix)

GDALResampleChunk32R_Gauss interpolates at wrong positions

Reported by: wkarel Owned by: warmerdam
Priority: normal Milestone: closed_because_of_github_migration
Component: default Version: unspecified
Severity: normal Keywords:
Cc:

Description

For the upper-/leftmost pixel of an overview with a scale factor of 2, GDALResampleChunk32R_Gauss does not interpolate the value at line 0, pixel 0, but it interpolates the value at line 1, pixel 1. The same is true for at least the rest of the upper/left image quadrant of the overview.

As nearest-neighbour resampling interpolates the value at line 0, pixel 0, I suppose that this is how it should be (and it makes sense, considering the easier geo-referencing of overviews).

I am unable to understand the need for the complexity of the current code. Anyway, there seems to be a simple fix, which is conditionally compiled in the attached source code - see 

#if 1
... fix
#else
... current code
#endif

Besides, the loop variable "j" is unused in 2 locations.

Still, thumbs up for implementing Gaussian resampling!

Attachments (1)

overview.cpp​ (131.6 KB ) - added by wkarel 8 years ago.

Download all attachments as: .zip

Change History (2)

by wkarel, 8 years ago

Attachment: overview.cpp​ added

comment:1 by Even Rouault, 5 years ago

Milestone: → closed_because_of_github_migration
Resolution: → wontfix
Status: new → closed

This ticket has been automatically closed because Trac is no longer used for GDAL bug tracking, since the project has migrated to GitHub. If you believe this ticket is still valid, you may file it to ​https://github.com/OSGeo/gdal/issues if it is not already reported there.

Note: See TracTickets for help on using tickets.