OpenCV threshold function

Question

I'm looking for an OpenCV function in python, that is similar to THRESH_TOZERO_INV, but instead of 0 it returns maxvalue.
So instead of:

 dst(x,y) = { 0 if src(x,y) > thresh src(x,y) otherwise }

I'm looking for:

 dst(x,y) = { maxvalue if src(x,y) > thresh src(x,y) otherwise }

Is there an option like that?

Answer 1

If you use THRESH_BINARY first, with a maxval of 1 then you will get a binary matrix with 0 s and 1 s. Call this matrix M . It has a 1 where src(x,y) > thresh and a 0 everywhere else.

Now compute

maxvalue * M + src * (1-M)

where * is the element-wise matrix-product and 1-M means a matrix with all 1 s minus M, ie invert the binary matrix M .