Defining Areas by Color Segmentation

Segmentation by Color takes advantage of the color information found in some clouds of points to segment it according to this information.

  1. From the Surface Reconstruction section of the action bar, click Segmentation by Color .
  2. Select the cloud to process.
  3. Pick a colored point in the cloud.
    • The color of this point is the reference color, that defines the points to be kept.
    • The RGB code of this color, as well as the color itself, are displayed in the dialog box.
    • The points to be kept are displayed with bigger symbols.
    • Nb of points indicates the percentage of points kept from the input cloud, with the current options.
  4. Set the Tolerance with the slider, between 0 and 1.

    This is the distance tolerance in percentage:

    • 0 (0%) means the color of the point to be kept must be strictly the same as the reference color.
    • 1 (100%) means any color matches the distance criterion, and all points are kept.

  5. Select a Color space, that is a mathematical model describing the colors.
    • RGB-Red/Green/Blue
    • YUV-Luma/U-Chrom./V-Chrom
    • HSL-Hue/Saturation/Lightness
  6. Once you have selected a color space, define the Distance formula for it, using the three sliders.

Two clouds are created:

  • Kept points contains the points kept.
  • Rejected points contains the other points.

 

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