Talk:Thresholding (image processing)

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I believe the improved threshold should be: (||G2||*m1+||G1||*m2)/(||G2||+||G1||).

[edit] Weighted average doesn't make sense

I removed the following:

Another approach is to calculate the new threshold in step four using the weighted average of m₁ and m₂: T’ = (||G₁||*m₁ + ||G₂||*m₂)/(||G₁||+||G₂||), where ||G_n|| is the number of pixels in G_n. This approach often gives a more accurate result.

because it appears to do nothing more than calculate the mean value of all the pixels, independent of the threshold value. The mean of G₁ pixels times the number of G₁ pixels is the sum of G₁ pixels. Same goes for G₂. The union of G₁ and G₂ is the whole image, so the sum of those products is the sum of all the pixels in the image and ||G₁|| + ||G₂ is the number of pixels in the image. Ergo, their quotient is the mean of all the pixels in the image.

Bryan Henderson 22:15, 20 May 2007 (UTC)