Specifies which value in an image should be interpreted as the darkest "shadow". All values "darker" than this value will be clipped to this value.
Whether darker values are smaller or larger can be determined by examining the Current value of ICAP_PIXELFLAVOR.
Single(float)
0
0 to 255
TW_ENUMERATION, TW_ONEVALUE, TW_RANGE
ICAP_PIXELFLAVOR