SBOU157 September   2015

 

  1.   Voxel Viewer
    1.     Trademarks
    2. 1 Introduction
      1. 1.1 TI 3D Depth Sensors
      2. 1.2 Operating Principles
      3. 1.3 Voxel Viewer and Voxel SDK
    3. 2 User Interface
      1. 2.1 Menu Bar
        1. 2.1.1 File
        2. 2.1.2 Settings
          1. 2.1.2.1 Camera Profiles
          2. 2.1.2.2 Edit Profiles
          3. 2.1.2.3 Statistics
        3. 2.1.3 Windows
        4. 2.1.4 Help
      2. 2.2 Source Bar
      3. 2.3 Main Viewport
      4. 2.4 Left Pane
        1. 2.4.1 Side Viewports
      5. 2.5 Right Pane
        1. 2.5.1 Frequently Used Parameters Window
        2. 2.5.2 Parameter List Window
      6. 2.6 Bottom Pane
        1. 2.6.1 Watch List and Statistics Window
        2. 2.6.2 Data Flow Diagram Window
        3. 2.6.3 Logs Window
    4. 3 Basic Operations
      1. 3.1 Connecting Devices
      2. 3.2 Adjusting the Settings
      3. 3.3 Visualizing the Data
        1. 3.3.1 Ambient
        2. 3.3.2 Amplitude
        3. 3.3.3 Depth
        4. 3.3.4 Distance
        5. 3.3.5 Phase
        6. 3.3.6 Point Clouds
        7. 3.3.7 Histogram
      4. 3.4 De-Noising
        1. 3.4.1 Temporal Filters
          1. 3.4.1.1 IIR Filter
          2. 3.4.1.2 Median Filter
        2. 3.4.2 Spatial Filters
          1. 3.4.2.1 Smooth Filter
          2. 3.4.2.2 Bilateral Filter
          3. 3.4.2.3 Median Filters
        3. 3.4.3 Recommended Starting Point
    5. 4 Calibration
      1. 4.1 Lens Calibration
      2. 4.2 Frequency Calibration
      3. 4.3 Crosstalk Calibration
      4. 4.4 Nonlinearity Calibration
      5. 4.5 Temperature Calibration
      6. 4.6 Common Phase Calibration
      7. 4.7 Pixel-Wise Calibration
      8. 4.8 Profiles and Calibration
    6. 5 TFC Programming
    7. 6 Summary
    8. 7 References

3.4.1.2 Median Filter

The temporal median filter samples by feeding data into a FIFO, sorting the buffer values, and taking the median value as the output. This effectively removes the extreme values, or noise, if the noise is characterized by intermittent spikes of extreme values. In ToF cameras, the “flying-pixels” effect can be reduced by this filter. The default dead band threshold is 0.05 (5%); that means if the new filtered value differs from the current value by less than 5%, the pixel does not change. This has a stabilizing effect on the output image.

fig18_sbou157.gifFigure 18. Temporal Median Filter Algorithm (Left) and Properties (Right)