H-maxima transform

In mathematical morphology, the h-maxima transform is a morphological operation used to filter local maxima of an image based on local contrast information. First, all local maxima are defined as connected pixels in a given neighborhood with intensity level greater than pixels outside the neighborhood. Second, all local maxima that have height ${\displaystyle f}$ lower or equal to a given threshold are suppressed. The height f of the remaining maxima is decreased by ${\displaystyle h}$.

The h-maxima transform is defined as the reconstruction by dilation of ${\displaystyle f}$ from ${\displaystyle f-h}$:

${\displaystyle \operatorname {HMAX} _{h}(f)=R_{f}^{\delta }(f-h)}$