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

Summary

Loads the specified image stream using specific options

Syntax

Objective-C

C++/CLI

Java

Python

public RasterImage Load( 
   Stream stream, 
   int bitsPerPixel, 
   CodecsLoadByteOrder order, 
   int firstPage, 
   int lastPage 
)

- (nullable LTRasterImage *)loadStream:(LTLeadStream *)stream  
                          bitsPerPixel:(NSInteger)bitsPerPixel  
                                 order:(LTCodecsLoadByteOrder)order  
                             firstPage:(NSInteger)firstPage  
                              lastPage:(NSInteger)lastPage  
                                 error:(NSError **)error

public RasterImage load(ILeadStream stream, int bitsPerPixel, CodecsLoadByteOrder order, int firstPage, int lastPage)

public: 
RasterImage^ Load(  
   Stream^ stream, 
   int bitsPerPixel, 
   CodecsLoadByteOrder order, 
   int firstPage, 
   int lastPage 
)

def Load(self,order,firstPage,lastPage):

Parameters

stream
A Stream containing the image data 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 stream.

Return Value

The RasterImage object that this method loads.

Remarks

The file can be in any supported image file format and bits per pixel, whether compressed or uncompressed.

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 show how to load an image using different bits/pixel and color order than that saved on disk. Also, it will show how to load a single page or a group of pages from a multipage file All loading operation uses a stream instead of a file on disk

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
public void LoadStream2Example() 
{ 
   RasterCodecs codecs = new RasterCodecs(); 
 
   string multiPageFileName = Path.Combine(LEAD_VARS.ImagesDir, "Eye.gif"); 
 
   FileStream fs = File.OpenRead(multiPageFileName); 
 
   // Get the file information (we are interested in the number of pages) 
   CodecsImageInfo info = codecs.GetInformation(fs, true); 
   Debug.WriteLine("Number of pages according to info: {0}", info.TotalPages); 
 
   // Load the first page 
   int first = 1; 
   int last = 1; 
   RasterImage image = codecs.Load(fs, 0, CodecsLoadByteOrder.BgrOrGray, first, last); 
   Debug.WriteLine("Loading pages {0} to {1}, pages loaded = {2}", first, last, image.PageCount); 
   Debug.Assert(image.PageCount == last - first + 1); 
   image.Dispose(); 
 
   // Load the second page 
   first = 2; 
   last = 2; 
   image = codecs.Load(fs, 0, CodecsLoadByteOrder.BgrOrGray, first, last); 
   Debug.WriteLine("Loading pages {0} to {1}, pages loaded = {2}", first, last, image.PageCount); 
   Debug.Assert(image.PageCount == last - first + 1); 
   image.Dispose(); 
 
   // Load from the second page to page before last 
   first = 2; 
   last = info.TotalPages - 1; 
   image = codecs.Load(fs, 0, CodecsLoadByteOrder.BgrOrGray, first, last); 
   Debug.WriteLine("Loading pages {0} to {1}, pages loaded = {2}", first, last, image.PageCount); 
   Debug.Assert(image.PageCount == last - first + 1); 
   image.Dispose(); 
 
   // load all the pages 
   image = codecs.Load(fs, 0, CodecsLoadByteOrder.BgrOrGray, 1, -1); 
   Debug.WriteLine("Loading all pages, pages loaded = {0}", image.PageCount); 
   Debug.Assert(image.PageCount == info.TotalPages); 
   image.Dispose(); 
 
   fs.Close(); 
 
   // Clean up 
   codecs.Dispose(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

 
import java.io.*; 
import java.net.*; 
import java.nio.file.Paths; 
import java.util.*; 
import java.time.Instant; 
import java.time.Duration; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.codecs.*; 
import leadtools.codecs.RasterCodecs.FeedCallbackThunk; 
import leadtools.drawing.internal.*; 
import leadtools.imageprocessing.*; 
import leadtools.imageprocessing.color.ChangeIntensityCommand; 
import leadtools.svg.*; 
 
 
public void loadStream2Example() throws IOException { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   RasterCodecs codecs = new RasterCodecs(); 
 
   String multiPageFileName = combine(LEAD_VARS_IMAGES_DIR, "Eye.gif"); 
 
   ILeadStream fs = LeadStreamFactory.create(multiPageFileName); 
 
   // Get the file information (we are interested in the number of pages) 
   CodecsImageInfo info = codecs.getInformation(fs, true); 
   System.out.println("Number of pages according to info: " + info.getTotalPages()); 
 
   // Load the first page 
   int first = 1; 
   int last = 1; 
   RasterImage image = codecs.load(fs, 0, CodecsLoadByteOrder.BGR_OR_GRAY, first, last); 
   System.out.println("Loading pages " + first + " to " + last + ", pages loaded = " + image.getPageCount()); 
   assertTrue(image.getPageCount() == last - first + 1); 
   image.dispose(); 
 
   // Load the second page 
   first = 2; 
   last = 2; 
   image = codecs.load(fs, 0, CodecsLoadByteOrder.BGR_OR_GRAY, first, last); 
   System.out.println("Loading pages " + first + " to " + last + ", pages loaded = " + image.getPageCount()); 
   assertTrue(image.getPageCount() == last - first + 1); 
   image.dispose(); 
 
   // Load from the second page to page before last 
   first = 2; 
   last = info.getTotalPages() - 1; 
   image = codecs.load(fs, 0, CodecsLoadByteOrder.BGR_OR_GRAY, first, last); 
   System.out.println("Loading pages " + first + " to " + last + ", pages loaded = " + image.getPageCount()); 
   assertTrue(image.getPageCount() == last - first + 1); 
   image.dispose(); 
 
   // load all the pages 
   image = codecs.load(fs, 0, CodecsLoadByteOrder.BGR_OR_GRAY, 1, -1); 
   System.out.println("Loading all pages, pages loaded = " + image.getPageCount()); 
   assertTrue(image.getPageCount() == info.getTotalPages()); 
   image.dispose(); 
 
   fs.close(); 
 
   // Clean up 
   codecs.dispose(); 
}