DTWAIN_GetContrastEx

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The DTWAIN_GetContrastEx function gets the current contrast value for the Source.

DTWAIN_FLOAT DTWAIN_GetContrastEx ( DTWAIN_SOURCE Source );

Parameters

Source

An open TWAIN Source.

lpContrast

Address of a DTWAIN_FLOAT (LPDTWAIN_FLOAT ). On return, this is filled in with the current contrast.

Return Values

If successful, the current contrast value. On failure, returns the minimum finite value representable by a DTWAIN_FLOAT (approximately 2.22507e-308). Call DTWAIN_GetLastError() to get extended information.

Comments

The DTWAIN_GetContrastEx function performs the same functionality as DTWAIN_GetContrast, with the difference being that the contrast is returned as a DTWAIN_FLOAT instead of the user providing a pointer to a DTWAIN_FLOAT as a parameter.

TWAIN State Transitions

The Source must be in State 4. or higher

Prerequisite Function Call(s)

DTWAIN_SysInitialize

DTWAIN Source Selection Function