PointCloudLibrary / PointCloudLibrary/pcl

'acos' missing in PPF feature calculation

Open
#1,171 10 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

module: features needs: feedback
Dominant language
C++
Stars
11.1k
Forks
4.7k
Avg merge
4d 10h
Merged PRs (30d)
6

Description

Hi everyone,

in the ppf.cpp file, in the function computePPFPairFeature the 'acos' should be applied to the f1, f2 and f3 components of the feature vector. In the paper, these components should be angles between 0 and pi, but in the function they are leaved as the inner products of the vectors.

The problem arises when using the PPFRegistration class, these features are discretized as if they were angles. This could lead to unexpected behavior.

Best,
Alfonso

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start in ppf.cpp at computePPFPairFeature and compare the f1, f2, and f3 calculations with the paper's angle definitions. Then inspect how PPFRegistration discretizes these features and verify that the resulting values are treated as angles between 0 and pi; check any relevant PPF tests or examples for expected behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
computer-vision
Issue type
Bug
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
52/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.