The WIA_IPS_YEXTENT property contains the current height, in pixels, of a selected image to acquire.
Property Type: VT_I4
Valid Values: WIA_PROP_RANGE
Access Rights: Read/write
An application sets the WIA_IPS_YEXTENT property to mark the upper-left corner (that is, the height) of a selection area to acquire. The WIA minidriver creates and maintains this property.
WIA_IPS_YEXTENT is required for all image acquisition enabled items and child items of these items; this property is not available for storage items or stored image items.
When a fixed page size is set, the driver has to set the WIA_IPS_XEXTENT, WIA_IPS_XPOS, WIA_IPS_YEXTENT, and WIA_IPS_YPOS properties to match the page size dimensions and a "0" origin. For center document alignment, the driver has to set WIA_IPS_XPOS to ((scan area width - document width) / 2) * resolution [DPI]) and WIA_IPS_YPOS to ((scan area height - document height) / 2) * resolution [DPI]).
When the origin or one extent is changed, the driver has to update the WIA_IPS_PAGE_SIZE to CUSTOM_SIZE and the WIA_IPS_PAGE_WIDTH and WIA_IPS_PAGE_HEIGHT properties to match the scan area extents. Orientation and rotation should not affect these properties, unless an orientation change (not a rotation change) renders the origin or one extent outside of the available document scan area.