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Load(Stream,LeadRect,int,CodecsLoadByteOrder,int,int) Method

Summary

Loads the specified rectangle from the specified image stream using the specified options.

Syntax
C#
VB
Objective-C
C++
Java
Public Overloads Function Load( _ 
   ByVal stream As Stream, _ 
   ByVal tile As LeadRect, _ 
   ByVal bitsPerPixel As Integer, _ 
   ByVal order As CodecsLoadByteOrder, _ 
   ByVal firstPage As Integer, _ 
   ByVal lastPage As Integer _ 
) As RasterImage 
- (nullable LTRasterImage *)loadStream:(LTLeadStream *)stream  
                                  tile:(LeadRect)tile  
                          bitsPerPixel:(NSInteger)bitsPerPixel  
                                 order:(LTCodecsLoadByteOrder)order  
                             firstPage:(NSInteger)firstPage  
                              lastPage:(NSInteger)lastPage  
                                 error:(NSError **)error 
public RasterImage load(ILeadStream stream, LeadRect tile, int bitsPerPixel, CodecsLoadByteOrder order, int firstPage, int lastPage) 

Parameters

stream
A Stream containing the image data to load.

tile
A LeadRect describing the tile/area of the image to load.

bitsPerPixel
Resulting image pixel depth. Valid values 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.

order
Color order for 16-bit, 24-bit, 32-bit, 48-bit, 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. The following are valid values.

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.

firstPage
1-based index of the first page to load.

lastPage
The 1-based index of the last page to load. Must be greater than or equal to firstPage. You can pass -1 to load from firstPage to the last page in the file.

Return Value

The RasterImage object that this method loads.

Remarks

This method loads a section of an image file (any format). The section begins is defined by tile rectangle.

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

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

Support for 12 and 16-bit grayscale, and 48 and 64-bit color images is only available in the Document/Medical Imaging editions.

For supported formats, refer to Summary of All Supported 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.

Example

This example will load the middle portion of the second page from a stream that contains a multipage file as 1 bits/pixel

C#
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
using LeadtoolsExamples.Common; 
 
public void LoadTileStream2Example() 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
 
   string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Eye.gif"); 
   string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1_LoadTileStream2.bmp"); 
 
   FileStream fs = File.OpenRead(srcFileName); 
 
   // Get the image dimension 
   int pageNumber = 2; 
   CodecsImageInfo info = codecs.GetInformation(fs, true, pageNumber); 
 
   // Load the middle portion of the page 
   int width = info.Width / 3; 
   int height = info.Height / 3; 
   LeadRect rc = new LeadRect( 
      (info.Width - width) / 2, 
      (info.Height - height) / 2, 
      width, 
      height); 
 
   RasterImage image = codecs.Load(fs, rc, 1, CodecsLoadByteOrder.Rgb, 2, 2); 
   fs.Close(); 
 
   Debug.Assert(image.PageCount == 1); 
   Debug.Assert(image.Width == rc.Width); 
   Debug.Assert(image.Height == rc.Height); 
 
   // Save this image back to disk 
   codecs.Save(image, destFileName, RasterImageFormat.Bmp, 1); 
   image.Dispose(); 
 
   // Clean up 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
} 

Requirements

Target Platforms

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Leadtools.Codecs Assembly