Description The top-hat filter is used to enhance low contrast high spatial frequency features within an image. The function works for only 8 bit per pixel grayscale images. Morphological top-hat of an image is defined as the difference between the original image and the graylevel opened image.
Examples
Syntax RetVal = [BiFilter.]GrayScaleTopHat hDib Mask Mheight Mwidth MPx MPy iShowProgress hWnd
Returns RetVal Long The handle of new filtered DIB, 0 if an error occurred, or –1 if the BIFilter.dll does not installed.
Remarks hDIB Long Handle of the image to filter.
Mask short* This parameter specifies the structuring function used by the filtering.
Mheight short Height of structuring matrix.
Mwidth short Width of structuring matrix.
MPx short X coordinate of structuring matrix origin.
MPy short Y coordinate of structuring matrix origin.
iShowProgress short This parameter specifies the displaying of the progressbar and the preview dialog.
Available values:
DISPLAY_NONE (0) – The progressbar and the preview dialog will not display before filtering.
DISPLAY_PROGRESS (1) – The progressbar will display during filtering procedure.
DISPLAY_DIALOG (2) – The preview dialog will display before filtering. This dialog shows the part of the image before and after filtering.
DISPLAY_BOTH (3) – The progressbar and the preview dialog will display.
IMPORTANT: The preview dialog will only display, if there is BIDlgs32.dll installed.
hWnd Long Handler of the parent window.
See Also