This is documentation for Mathematica 7, which was
based on an earlier version of the Wolfram Language.

# BottomHatTransform

 BottomHatTransform[image, ker] gives the morphological bottom-hat transform of image with respect to structuring element ker. BottomHatTransform[image, r]gives the bottom-hat transform with respect to a range r square.
• The structuring element ker is a matrix containing 0s and 1s.
• If multiple image channels are present, BottomHatTransform operates on each of them separately.
• BottomHatTransform preserves regions smaller than the structuring element whose channel values are smaller than their surroundings.
Bottom-hat transform applied to a color photo:
Extract small dark regions from a color image:
Use a disk-shaped structuring element to extract washers that are smaller than the specified size:
The bottom-hat transform effectively inverts high-frequency regions:
Bottom-hat transform applied to a color photo:
 Out[1]=

Extract small dark regions from a color image:
 Out[1]=

Use a disk-shaped structuring element to extract washers that are smaller than the specified size:
 Out[1]=

The bottom-hat transform effectively inverts high-frequency regions:
 Applications   (1)
Extract thin dark features:
Add the result to the original image to remove those thin features:
New in 7