Description

Use the Bottom-hat block to perform bottom-hat filtering on an intensity or binary image using a predefined neighborhood or structuring element. Bottom-hat filtering is the equivalent of subtracting the input image from the result of performing a morphological closing operation on the input image. This block uses flat structuring elements only.

If your input image is a binary image, for the Input image type parameter, select Binary. If your input image is an intensity image, select Intensity.

Use the Neighborhood or structuring element source parameter to specify how to enter your neighborhood or structuring element values. If you select Specify via dialog, the Neighborhood or structuring element parameter appears in the dialog box. If you select Input port, the Nhood port appears on the block. Use this port to enter your neighborhood values as a matrix or vector of 1s and 0s. You can only specify a structuring element using the dialog box.

Use the Neighborhood or structuring element parameter to define the region the block moves throughout the image. Specify a neighborhood by entering a matrix or vector of 1s and 0s. Specify a structuring element with the strel function from the Image Processing Toolbox™. If the structuring element is decomposable into smaller elements, the block executes at higher speeds due to the use of a more efficient algorithm.

Parameters

See Also