DTWAIN_GetContrast

The DTWAIN_GetContrast function sets the current contrast value for the Source.

DTWAIN_BOOL DTWAIN_GetContrast (

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

The return value is TRUE if successful.  Otherwise FALSE is returned.

Comments

The DTWAIN_GetContrast function gets the current contrast value for the  Source Source and on return, fills the DTWAIN_FLOAT that lpContrast points to .  Please note that lpContrast is an address of a DTWAIN_FLOAT (an LPDTWAIN_FLOAT).

The contrast can be in the range between -1000.0 and +1000.0, with 0.0 being the default value for the contrast.  Note that some Sources do not support retrieving the contrast, so the return value for DTWAIN_GetContrast will always be FALSE.

To set the current contrast value, call DTWAIN_SetContrast.

For languages that have difficulties with DTWAIN_FLOAT parameters, the alternate function that can be used as a replacement for DTWAIN_GetContrast is DTWAIN_GetContrastString.

TWAIN State Transitions

The Source must be in State 4. or higher

Prerequisite Function Call(s)

DTWAIN_SysInitialize

DTWAIN Source Selection Function

See Also

Setting / Getting Contrast Level