Expand Minimize

WIA_IPA_COMPRESSION

The WIA_IPA_COMPRESSION property contains the current compression type that is used. The WIA minidriver creates and maintains this property.

Property Type: VT_I4

Valid Values: WIA_PROP_LIST

Access Rights: Read/write (image acquisitions); read-only (image storage)

Remarks

An application reads the WIA_IPA_COMPRESSION property to determine the image compression type, or the application sets this property to configure the compression setting.

The following table describes the constants that are valid with WIA_IPA_COMPRESSION.

ValueDefinition

WIA_COMPRESSION_BI_RLE4

RLE 4 compression

WIA_COMPRESSION_BI_RLE8

RLE 8 compression

WIA_COMPRESSION_G3

Group 3 compression

WIA_COMPRESSION_G4

Group 4 compression

WIA_COMPRESSION_JBIG*

IS 11544 (ITU-T T.82) compression

WIA_COMPRESSION_JPEG

JPEG compression

WIA_COMPRESSION_JPEG2K*

JPEG 2000 compression

WIA_COMPRESSION_NONE

No compression

WIA_COMPRESSION_PNG*

W3C PNG compression

 

Values that are marked with an asterisk (*) are for Windows Vista and later operating systems only.

Note   When the file format is WiaImgFmt_XPS or WiaImgFmt_PDFA, WIA_COMPRESSION_NONE means "not defined"; the device cannot choose the internal compression (if any) for images that are stored in these two document formats.

All WIA 2.0 minidrivers must set the initial value of this property to its default value, which is WIA_COMPRESSION_NONE.

The access rights of the WIA_IPA_COMPRESSION property are read/write for all image acquisitions but read-only for stored image items.

Requirements

Header

Wiadef.h (include Wiadef.h)

 

 

Send comments about this topic to Microsoft

Show:
© 2014 Microsoft