UseDpi Property (RasterThumbnailBrowser)


Gets or sets a value that indicates whether LEAD's automated scaling properties are used to account for the physical resolution of the bitmap.


public bool UseDpi {get; set;} 
property bool UseDpi { 
   bool get(); 
   void set (    bool ); 

Property Value

true Account for the physical resolution. Default value is false.


The physical resolution of an image is measured in dots per inch (DPI). When you load an image, the Leadtools.RasterImage.XResolution and Leadtools.RasterImage.YResolution properties are updated with the DPI values for the horizontal and vertical resolution. Some images have different horizontal and vertical resolutions. For example, the horizontal resolution of a fax image is typically twice its vertical resolution (for example 200 by 100). In such cases, the displayed images will appear elongated if you do not account for the resolution. If the values of the Leadtools.RasterImage.XResolution property and the Leadtools.RasterImage.YResolution property are not equal, set the UseDpi property to true to have LEAD's automated scaling properties account for the physical resolution of the image when Items are painted by OnPaint


using Leadtools.WinForms; 
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
class MyForm1 : Form 
   public RasterImageList imageList; 
   public MyForm1(string title) 
      Text = title; 
      // Set the size of the form 
      Size = new Size(400, 200); 
      // Create a new RasterImageList control. 
      imageList = new RasterImageList(); 
      imageList.Bounds = new Rectangle(new Point(0, 0), Size); 
      imageList.Sorting = SortOrder.Ascending; 
      imageList.BorderStyle = BorderStyle.None; 
      imageList.DoubleBuffer = true; 
      imageList.Dock = DockStyle.Fill; 
      RasterPaintProperties paintProperties = imageList.PaintProperties; 
      paintProperties.PaintDisplayMode = RasterPaintDisplayModeFlags.Bicubic; 
      imageList.PaintProperties = paintProperties; 
      imageList.EnableKeyboard = true; 
      imageList.UseDpi = true; 
      // Add a handler to the PaintBackground event 
      imageList.PaintBackground += new PaintEventHandler(rasterImageList_PaintBackground); 
      RasterCodecs codecs = new RasterCodecs(); 
      // Create three items 
      string imagesPath = LEAD_VARS.ImagesDir; 
      for (int i = 0; i < 3; i++) 
         // Load the image 
         int index = i + 1; 
         string imageFileName = Path.Combine(imagesPath, @"ImageProcessingDemo\Image" + index.ToString() + ".cmp"); 
         RasterImage image = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1); 
         RasterImageListItem item = new RasterImageListItem(image, 1, "Item" + index.ToString()); 
         // Select the first item 
         if (i == 0) 
            item.Selected = true; 
         // Add the item to the image list 
      // Add the RasterImageList to the control collection. 
   private void rasterImageList_PaintBackground(object sender, PaintEventArgs e) 
      // Get the image list control 
      RasterImageList imageList = sender as RasterImageList; 
      // Fill the background with a gradient brush 
      Rectangle rc = imageList.ClientRectangle; 
      Brush b = new LinearGradientBrush( 
      e.Graphics.FillRectangle(b, rc); 
public void RasterImageList_RasterImageList(string title) 
   MyForm1 form = new MyForm1(title); 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 


Target Platforms

See Also


RasterThumbnailBrowser Class

RasterThumbnailBrowser Members

Help Version 22.0.2023.2.9
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Leadtools.WinForms Assembly

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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.