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Compression Property

Summary
Gets or sets the compression to be used while performing data transfer from WIA source.

Syntax
C#
C++/CLI
Python
public WiaCompressionMode Compression { get; set; } 
public: 
property WiaCompressionMode Compression { 
   WiaCompressionMode get(); 
   void set (    WiaCompressionMode ); 
} 
Compression # get and set (WiaDataTransferProperties) 

Property Value

The compression to be used while performing data transfer from WIA source. Possible values are (according to Microsoft SDK documentation):

WiaCompressionMode.None

No compression is to be used.

WiaCompressionMode.Rle4

RLE4 compression.

WiaCompressionMode.Rle8

RLE8 compression.

WiaCompressionMode.Group3

Group 3 compression.

WiaCompressionMode.Group4

Group 4 compression.

WiaCompressionMode.Jpeg

JPEG compression.

WiaCompressionMode.Jbig

JBIG compression (only supported in Windows Vista or later).

WiaCompressionMode.Jpeg2000

JPEG 2000 compression (only supported in Windows Vista or later).

WiaCompressionMode.Png

PNG compression (only supported in Windows Vista or later).

For more information about these compression types, refer to WIA_IPA_COMPRESSION property ID in Microsoft Windows SDK Documentation.

Example
C#
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Wia; 
 
 
WiaSession wiaSession; 
       
public void GetRootItemExample(IntPtr parent) 
{ 
   if (!WiaSession.IsAvailable(WiaVersion.Version1)) 
   { 
      Console.WriteLine("WIA version 1.0 not installed."); 
      return; 
   } 
   wiaSession = new WiaSession(); 
   wiaSession.Startup(WiaVersion.Version1); 
 
   DialogResult res = wiaSession.SelectDeviceDlg(parent, WiaDeviceType.Default, WiaSelectSourceFlags.NoDefault); 
   if (res != DialogResult.OK) 
   { 
      Console.WriteLine("Error selecting WIA device."); 
      wiaSession.Shutdown(); 
      return; 
   } 
 
   object rootItem = wiaSession.GetRootItem(null); 
   if (rootItem != null) 
   { 
      wiaSession.EnumItemsEvent += new EventHandler<WiaEnumItemsEventArgs>(wiaSession_EnumItemsEvent); 
 
      wiaSession.EnumChildItems(rootItem); 
 
      wiaSession.EnumItemsEvent -= new EventHandler<WiaEnumItemsEventArgs>(wiaSession_EnumItemsEvent); 
   } 
 
   wiaSession.Shutdown(); 
} 
 
void wiaSession_EnumItemsEvent(object sender, WiaEnumItemsEventArgs e) 
{ 
   if (e.Item != null) 
   { 
      WiaDataTransferProperties dataTransfer = WiaDataTransferProperties.Empty; 
      WiaImageEffectsProperties imageEffects = WiaImageEffectsProperties.Empty; 
 
      WiaProperties properties = wiaSession.GetProperties(e.Item); 
 
      dataTransfer.ImageDataType = WiaImageDataType.Grayscale; 
      imageEffects.Brightness = 250; 
 
      properties.DataTransfer = dataTransfer; 
      properties.ImageEffects = imageEffects; 
      properties.ScanningMode = WiaScanningModeFlags.Feeder;   // set scanning source to Feeder 
      properties.MaximumNumberOfPages = 0;                     // scan all pages in feeder 
      properties.ImageType = WiaImageType.Grayscale; 
      properties.Orientation = WiaOrientation.Portrait; 
 
      WiaImageResolutionProperties imageResolution = properties.ImageResolution; 
      imageResolution.BitsPerPixel = 8; 
      imageResolution.HorizontalResolution = 600; 
      imageResolution.VerticalResolution = 600; 
      properties.ImageResolution = imageResolution; 
 
      wiaSession.SetPropertiesEvent += new EventHandler<WiaSetPropertiesEventArgs>(wiaSession_SetPropertiesEvent); 
 
      wiaSession.SetProperties(e.Item, properties); 
 
      wiaSession.SetPropertiesEvent -= new EventHandler<WiaSetPropertiesEventArgs>(wiaSession_SetPropertiesEvent); 
 
      wiaSession.FreeItem(e.Item); 
   } 
} 
 
void wiaSession_SetPropertiesEvent(object sender, WiaSetPropertiesEventArgs e) 
{ 
   if (e.Error <= 0) 
   { 
      Console.WriteLine("Failed to set the below property:\n\tProperty Id: {0}\n\tProperty Value: {1}\n\tError: {2}\n\n", e.PropertyId.ToString(), e.Value.ToString(), e.Error.ToString()); 
   } 
} 
Requirements

Target Platforms

Help Version 23.0.2024.2.29
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Leadtools.Wia Assembly
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.