Reflection Filter

The reflection filter removes points that it deems impacted by reflections and thus erroneous. In the point cloud, such points are typically seen as “ghost planes”. “Ghost planes” are small regions of points floating mid-air that shouldn’t be there, typically stretching towards or away from the Zivid camera.

Zivid knows how the signals it sends out from the projector should look like. For this reason it is possible to assess whether or not the data that is read back by the camera makes sense. The reflection filter, therefore, attempts to discard pixels that are deemed to be tampered with as a result of one of the following:

  • Interreflections

  • Excessive movements in the scene

  • Alternating alien light sources

    • For example a second Zivid 3D camera that projects onto the same scene at the same time.

The Reflection filter has two modes, Local and Global mode.

  • Local mode: This mode preserves more 3D data on thinner objects and it’s better at removing reflection artifacts such as ghost planes and highlights. It also processes faster than the Global filter.

  • Global mode: This mode is better at removing outlier points in the point cloud as well as preserving the edges of objects. This is the default mode.

The reflection filter can be turned on or off.

Note

Reflection filter (Global mode) adds the following processing time per 3D capture:

Expected median (±stddev) in ms

Filter

Zivid One+

Zivid Two

Intel UHD 750

Intel UHD G1

NVIDIA 3070

Intel UHD 750

NVIDIA 3070

High-end 1

Low-end 2

High-end 3

High-end 3

Reflection

13 (±5) ms

17 (±2) ms

10 (±0.4) ms

19 (±5) ms

11 (±0.5) ms

1

High-end machine with GPU: Intel UHD Graphics 750 (ID:0x4C8A) and CPU: 11th Gen Intel(R) Core(TM) i9-11900K @ 3.50GHz

2

Low-end machine with GPU: Intel UHD Graphics G1 (ID:0x8A56) and CPU: Intel(R) Core(TM) i3-1005G1 CPU @ 1.20GHz

3(1,2)

High-end machine with GPU: NVIDIA GeForce RTX 3070 and CPU: 11th Gen Intel(R) Core(TM) i9-11900K @ 3.50GHz

Version History

SDK

Changes

1.4.0

Reflection filter is improved to remove fewer good points.

2.7.0

Reflection filter is updated with a new mode called Local. Old mode is renamed to Global.