LoadAsync(ILeadStream,Int32,Int32,Int32,RasterSizeFlags,CodecsLoadByteOrder) Method

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Visual Basic
WinRT C#
Java
Objective-C
WinRT JavaScript
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public IAsyncOperation<RasterImage> LoadAsync( 
   ILeadStream stream,
   int width,
   int height,
   int bitsPerPixel,
   RasterSizeFlags flags,
   CodecsLoadByteOrder order
)

'Declaration

Public Overloads Function LoadAsync( _
   ByVal stream As ILeadStream, _
   ByVal width As Integer, _
   ByVal height As Integer, _
   ByVal bitsPerPixel As Integer, _
   ByVal flags As RasterSizeFlags, _
   ByVal order As CodecsLoadByteOrder _
) As IAsyncOperation(Of RasterImage)

'Usage

Dim instance As RasterCodecs
Dim stream As ILeadStream
Dim width As Integer
Dim height As Integer
Dim bitsPerPixel As Integer
Dim flags As RasterSizeFlags
Dim order As CodecsLoadByteOrder
Dim value As IAsyncOperation(Of RasterImage)
 
value = instance.LoadAsync(stream, width, height, bitsPerPixel, flags, order)

public IAsyncOperation<RasterImage> LoadAsync( 
   ILeadStream stream,
   int width,
   int height,
   int bitsPerPixel,
   RasterSizeFlags flags,
   CodecsLoadByteOrder order
)

 function Leadtools.Codecs.RasterCodecs.LoadAsync(ILeadStream,Int32,Int32,Int32,RasterSizeFlags,CodecsLoadByteOrder)( 
   stream ,
   width ,
   height ,
   bitsPerPixel ,
   flags ,
   order 
)

public:
IAsyncOperation<RasterImage^>^ LoadAsync( 
   ILeadStream^ stream,
   int width,
   int height,
   int bitsPerPixel,
   RasterSizeFlags flags,
   CodecsLoadByteOrder order
)

Parameters

stream: An ILeadStream containing the image data to load.
width: New width of the image in pixels.
height: New height of the image in pixels.
bitsPerPixel: Resulting image pixel depth.
flags: Flag that indicates the type of resizing to use.
order: Color order for 16-, 24-, 32-, 48-, and 64-bit images. If the resulting image is less than 16 bits per pixel, this will have no effect since palletized images have no order.

Return Value

When this method completes, it returns the image as a RasterImage.

LEADTOOLS will attempt to load corrupted files so you can see at least a portion of the image. For such images, the load methods succeed, but the LoadStatus will return an error code.

Valid values are for the flags parameter are:

Value	Meaning
RasterSizeFlagsRasterSizeFlags.None	Normal resizing
RasterSizeFlagsRasterSizeFlags.Resample	Linear interpolation resizing
RasterSizeFlagsRasterSizeFlags.Bicubic	Bicubic interpolation resizing
RasterSizeFlagsRasterSizeFlags.FavorBlack	Not supported

Valid values are for the bitsPerPixel parameter are:

Value	Meaning
0	Keep the original file's pixel depth (Do not convert).
1 to 8	The specified bits per pixel in the resulting image.
12	12 bits per pixel in the resulting image.
16	16 bits per pixel in the resulting image.
24	24 bits per pixel in the resulting image.
32	32 bits per pixel in the resulting image.
48	48 bits per pixel in the resulting image.
64	64 bits per pixel in the resulting image.

Valid values are for the order parameter are:

Value	Meaning
CodecsLoadByteOrder.Rgb	Red, green, and blue color order in memory
CodecsLoadByteOrder.Bgr	Blue, green, and red color order in memory
CodecsLoadByteOrder.Gray	12 or 16-bit grayscale image. 12 and 16-bit grayscale images are only supported in the Document/Medical Imaging editions.
CodecsLoadByteOrder.RgbOrGray	Load the image as red, green, blue OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions
CodecsLoadByteOrder.BgrOrGray	Load the image as blue, green, red OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions
CodecsLoadByteOrder.Romm	ROMM order. ROMM only supports 24 and 48-bit images
CodecsLoadByteOrder.BgrOrGrayOrRomm	Load the image as red, green, blue OR as a 12 or 16-bit grayscale image OR as ROMM. 12 and 16-bit grayscale images are supported in the Document/Medical Imaging editions only. ROMM only supports 24 and 48-bit color images.

Use the CodecsLoadOptions class to set up other load option parameters before calling this method.

Support for 12 and 16-bit grayscale images is only available in the Document/Medical Imaging editions.

For supported formats, refer to Summary of All Supported Image File Formats.

LEADTOOLS loads all PDF files as Raster PDF uncompressed RasterImageFormat.RasPdf, regardless of the compression and color space used when saving the file.

The RasterCodecs class supports loading image files asynchronously using the LoadAsync methods. When calling any of these methods, the caller thread will not be blocked and the method will return instantly with an instance of RasterImage that is in a loading status (RasterImage.IsLoading set to true). You should not use the other properties of this object while the object is in loading status.

When the RasterCodecs object finishes loading the image, the various properties of the RasterImage will be populated with the image information and data and the RasterImage.IsLoading property will be set to false.

Do not poll the RasterImage.IsLoading property to determine whether the image has finished loading. Instead, subscribe to the IAsyncOperation.Completed event to get notification when the LoadAsync operation has completed and whether any errors occurred.

When this method completes, it returns the image as a RasterImage.

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

RasterCodecsExamples.prototype.LoadResize1Example = function ( ) 
{
   Tools.SetLicense ( ) ;
   with (Leadtools) {
      with (Leadtools.Codecs) {
         var codecs = new RasterCodecs();
         var image;
         var srcFileName = "Assets\\Image1.cmp";
         var destFileName = "LoadResize1.bmp";

         // We want to load the image as 320/200
         var width = 320;
         var height = 200;

         return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
            return codecs.loadAsync(LeadStreamFactory.create(loadFile), width, height, 0, RasterSizeFlags.resample, CodecsLoadByteOrder.bgrOrGray)
         })
            .then(function (img) {
               image = img;

               console.assert(image.width == width);
               console.assert(image.height == height);

               // Save this image back to disk
               return Tools.AppLocalFolder().createFileAsync(destFileName)
            })
         .then(function (saveFile) {
            return codecs.saveAsync(image, LeadStreamFactory.create(saveFile), RasterImageFormat.bmp, 24)
         })
         .then(function () {

            image.close();

            // Clean up
            codecs.close();
         },
            function (ex) {
               var error = "";
               var rasterException = RasterException.fromHResult(ex.number);
               if (rasterException != null)
                  error = rasterException.message;
               else
                  error = ex.message;
               console.info(error);
            }
            );
      }
   }
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;

      
public async Task LoadResize1Example()
{
   RasterCodecs codecs = new RasterCodecs();
   string srcFileName = @"Assets\Image1.cmp";
   string destFileName = @"LoadResize1.bmp";

   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);

   // We want to load the image as 320/200
   int width = 320;
   int height = 200;

   RasterImage image = null;
   try
   {
      image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile),
         width,
         height,
         0,
         RasterSizeFlags.Resample,
         CodecsLoadByteOrder.BgrOrGray);
   }
   catch (Exception ex)
   {
      string error = "";
      RasterException rasterException = RasterException.FromHResult(ex.HResult);
      if (rasterException != null)
         error = rasterException.Message;
      else
         error = ex.Message;
      Debug.WriteLine(error);
      Assert.Fail(error);
   }

   Assert.IsTrue(image.Width == width);
   Assert.IsTrue(image.Height == height);

   // Save this image back to disk
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), RasterImageFormat.Bmp, 24);

   image.Dispose();

   // Clean up
   codecs.Dispose();
}

Target Platforms

Reference

RasterCodecs Class
RasterCodecs Members
Overload List
Loading and Saving Images
Loading and Saving Large TIFF / BigTIFF Files
Speeding Up 1-Bit Documents
Fast File Info