Description This method will adjust the input image’s levels automatically. AutoLevels filtering clips iPercent percent of colors (iPercent/2 from darkest colors and iPercent/2 from lightest colors) and then stretches the image’s histogram to the 0..255 range. AutoLevels filtering filters the color channels of the image separately. This method works for only 8 and 24 bit per pixel images.
Examples
The original 180 x 210 pixel image and the AutoLeveled image with iPercent = 10 parameter value.
Syntax RetVal = [BiFilter.]FilterAutoLevels hDib iPercent iShowProgress hWnd
Returns RetVal LONGLONG The handle of new filtered DIB, 0 if an error occurred, or -1 if the BIFilter.dll does not installed.
Remarks hDib LONGLONG Handle of the image to filter.
iPercent short Percent of colors to be clipped.
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 LONGLONG Handler of the parent window.
See Also