BUG: #2046 Add an epsilon margin to compute the m_ReachableOutputRegion (!714) · Merge Requests · Main Repositories / otb

BUG: #2046 Add an epsilon margin to compute the m_ReachableOutputRegion

Summary

The application Superimpose crashed with a segmentation fault during resampling. Investigation revealed that the interpolated index was out of image bounds. The application uses the PHR mode and resamples the XS image with a otb::GridResampleImageFilter. This filter doesn't check explicitly that input indexes are in the input buffered region. It uses a m_ReachableOutputRegion to crop the output region processed. The problem appears because an output pixel is right on the border of the input image extent, and when someone uses a nearest neighbor interpolator, this one converts the continuous index to an out-of-bound index.

The solution was to introduce an epsilon margin to compute the m_ReachableOutputRegion.

Rationale

Closes #2046 (closed)

Implementation Details

Classes and files

otbGridResampleImageFilter: Add new attribute m_InterpolationMargin with corresponding get/set. Set it's default value to 0.0. Use it in processing.

Applications

Superimpose: Set the margin to 1e-9 when using nearest neighbor interpolation.

Tests

Added a new test for the Superimpose application with PHR images and nearest neighbor interpolation.

Copyright

The copyright owner is CNES and has signed the ORFEO ToolBox Contributor License Agreement.

Check before merging:

All discussions are resolved
At least 2 👍 votes from core developers, no 👎 vote.
The feature branch is (reasonably) up-to-date with the base branch
Dashboard is green
Copyright owner has signed the ORFEO ToolBox Contributor License Agreement
Optionally, run git diff develop... -U0 --no-color | clang-format-diff.py -p1 -i on latest changes and commit

#### Summary

The application **Superimpose** crashed with a segmentation fault during
resampling. Investigation revealed that the interpolated index was out
of image bounds. The application uses the PHR mode and resamples the XS
image with a `otb::GridResampleImageFilter`. This filter doesn't check
explicitly that input indexes are in the input buffered region. It
uses a `m_ReachableOutputRegion` to crop the output region
processed. The problem appears because an output pixel is right on the
border of the input image extent, and when someone uses a nearest neighbor
interpolator, this one converts the continuous index to an
out-of-bound index.

The solution was to introduce an *epsilon* margin to compute the 
`m_ReachableOutputRegion`.

#### Rationale

Closes #2046

#### Implementation Details

##### Classes and files
*otbGridResampleImageFilter*: Add new attribute `m_InterpolationMargin` with corresponding get/set. Set it's default value to 0.0. Use it in processing.

##### Applications
*Superimpose*: Set the margin to 1e-9 when using *nearest neighbor* interpolation.

##### Tests
Added a new test for the Superimpose application with PHR images and *nearest neighbor* interpolation.

#### Copyright

The copyright owner is *CNES* and has signed the ORFEO ToolBox Contributor License Agreement.

<hr>

***Check before merging:***

- All discussions are resolved
- At least 2 :thumbsup: votes from core developers, no :thumbsdown: vote.
- The feature branch is (reasonably) up-to-date with the base branch
- Dashboard is green
- Copyright owner has signed the ORFEO ToolBox Contributor License Agreement
- Optionally, run `git diff develop... -U0 --no-color | clang-format-diff.py -p1 -i` on latest changes and commit