Set Image DPI

One capability that is often set by the application is the desired DPI of the scanned image. To set the DPI for scanned images, use the TWAIN capabilities: ICAP_XRESOLUTION and ICAP_YRESOLUTION.

It is important to set the ICAP_UNITS capability equal to TWUN_INCHES prior to setting the resolution capabilities.

VB Example	Copy Code
' This code demonstrates how to set the DPI of scanned images to 300 DPI TwainPRO1.Capability = ICAP_UNITS If TwainPRO1.CapSupported Then TwainPRO1.CapTypeOut = 0 TwainPRO1.CapValueOut = 0 TwainPRO1.SetCapOut End If TwainPRO1.Capability = ICAP_XRESOLUTION If TwainPRO1.CapSupported Then TwainPRO1.CapTypeOut = 0 TwainPRO1.CapValueOut = 300 TwainPRO1.SetCapOut End If TwainPRO1.Capability = ICAP_YRESOLUTION If TwainPRO1.CapSupported Then TwainPRO1.CapTypeOut = 0 TwainPRO1.CapValueOut = 300 TwainPRO1.SetCapOut End If

VB Example

Copy Code

' This code demonstrates how to set the DPI of scanned images to 300 DPI
TwainPRO1.Capability = ICAP_UNITS
If TwainPRO1.CapSupported Then
TwainPRO1.CapTypeOut = 0
TwainPRO1.CapValueOut = 0
TwainPRO1.SetCapOut
End If

TwainPRO1.Capability = ICAP_XRESOLUTION
If TwainPRO1.CapSupported Then
TwainPRO1.CapTypeOut = 0
TwainPRO1.CapValueOut = 300
TwainPRO1.SetCapOut
End If

TwainPRO1.Capability = ICAP_YRESOLUTION
If TwainPRO1.CapSupported Then
TwainPRO1.CapTypeOut = 0
TwainPRO1.CapValueOut = 300
TwainPRO1.SetCapOut
End If

Image Resolution can only be modified, or set, after a TWAIN Session has been opened (OpenSession), and prior to initiating the scanning session (StartSession).