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Chapter 8 - Video Digitizer Components / Video Digitizer Components Reference

Video Digitizer Component Functions / Controlling Analog Video

VDGetContrast

The VDGetContrast function returns the current contrast value. The contrast value ranges from 0 to 65,535, where 0 represents no change to the basic image and larger values increase the contrast of the video image (that is, increase the slope of the transform).

pascal VideoDigitizerError VDGetContrast
                              (VideoDigitizerComponent ci,
                               unsigned short *contrast);

ci

Specifies the video digitizer component for the request. Applications obtain this reference from the Component Manager's OpenComponent function.

contrast

Contains a pointer to an integer that is to receive the current contrast value. The video digitizer component places the contrast value into the field referred to by this parameter.

RESULT CODES

noErr	0	No error
digiUnimpErr	-2201	Function not supported

SEE ALSO

Your application can set the contrast value by calling the VDSetContrast function (described in the previous section). To obtain the recommended contrast value, your application can call the VDGetVideoDefaults function (described on page 8-66).

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