Segmentation > Basic Threshold

Selects pixels based on whether they are below or above a certain pixel value. “Auto” determines this threshold value using Otsu’s method, which chooses the value which minimizes the average grayscale variance of the pixels which have been selected and not selected.

1. Mode

  • Manual: Allows manual selection of threshold value
  • Auto: Auto-determines threshold value based on Otsu’s method [1]
    - Adjustment: Specifies offset to make to auto-determined threshold value.

2. Select

  • Dark: Selects pixels whose values are below the threshold value
  • Bright: Selects pixels whose values are above the threshold value

3. Value

Threshold value which sets pixels as selected or not

References

[1] Otsu, N., “A Threshold Selection Method from Gray-Level Histograms,” IEEE Transactions on Systems, Man, and Cybernetics, Vol. 9, No. 1, 1979, pp. 62-66.

Tips

  • Avoid using a Basic Threshold without any pre-processing. This often results in subjective, inconsistent results.
  • Recommend trying a Smart Cluster or other image normalization technique before applying a threshold.

Need more help with this?
Chat with an expert now ››

Was this helpful?

Yes No
You indicated this topic was not helpful to you ...
Could you please leave a comment telling us why? Thank you!
Thanks for your feedback.