DTWAIN_SetLightPath
The DTWAIN_SetLightPath enables transmissive or reflective acquisitions.
DTWAIN_BOOL DTWAIN_SetLightPath (
Parameters Source An open TWAIN Source.
LightPath The light path to use.
Return Values The return value is TRUE if successful. Otherwise FALSE is returned.
Comments The DTWAIN_SetLightPath function sets the Source light path to either reflective or transmissive. The LightPath parameter determines whether to use reflective or transmissive. For reflective, LightPath must be DTWAIN_LP_REFLECTIVE. For transmissive, LightPath must be DTWAIN_LP_TRANSMISSIVE.
Transmissive scanning is required if scanning films or transparencies. Reflective scanning is used for normal (paper) scanning. By turning on transmissive scanning, scanners equipped with a transparency adapter can be utilized.
To determine if the device supports setting the light path, call DTWAIN_IsLightPathSupported. To get the current light path, call DTWAIN_GetLightPath.
Example To turn on the transparency adapter for many scanners, the following example demonstrates setting the light path to use the transparency adapter:
void ScanTransparency( ) { /* ... */ DTWAIN_SOURCE Source; Source = DTWAIN_SelectSource( ); if ( DTWAIN_IsLightPathSupported( Source ) ) { /* Turn on transparency adapter */ DTWAIN_SetLightPath( Source, DTWAIN_LP_TRANSMISSIVE ); } /* ... */ }
To turn off the transparency adatper a call to DTWAIN_SetLightPath with the LightPath as DTWAIN_LP_REFLECTIVE must be done.
TWAIN State Transitions The Source must be in State 4. or higher
Prerequisite Function Call(s) DTWAIN Source Selection Function
See Also |