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GetImage(int) Method

Summary

Gets this page as a raster image at the specified resolution.

Syntax

C#
VB
Java
C++
public RasterImage GetImage( 
   int resolution 
) 
Public Function GetImage() As RasterImage 
public:  
   RasterImage^ GetImage() 
public RasterImage getImage(int resolution) 

Parameters

resolution

Resolution to use in dots per inch. If this value is 0, then the current page Resolution value is used.

Return Value

This page as a RasterImage object.

Remarks

GetImage and GetImage(resolution) are used to get a raster image representation of this page. All document types support this method and it will always return a value object.

SetImage is used to replace the raster image of the page. IsImageModified is used to as flag that indicates that the image of this page has been replaced by the user.

If this document type supports loading raster images at any resolution (the value of DocumentImages.IsResolutionsSupported is true), then this method will use the resolution parameter instead of the Resolution property when loading the image.

If this document type does not support loading raster images at any resolution (the value of DocumentImages.IsResolutionsSupported is false), then resolution is ignored and the original page Resolution value is used.

This method works as follows (the "item" is a raster image with the specified resolution):

  1. If an item was found in the cache, it is returned right away. This is available if the document was created using the cache system. and Document.CacheOptions contains DocumentCacheOptions.PageImage.

  2. If this is an original page in the source document file (the value of OriginalPageNumber is not -1), then RasterCodecs is used to load the RasterImage object from the original page.

  3. If this is not an original page in the source document file (the value of OriginalPageNumber is not 1), then a new RasterImage object is created based on the page size and resolution and the default values in DocumentImages.

  4. If this document uses the cache system (Document.HasCache is true), then the RasterImage object is saved to the cache before it is returned. Next time this method is called, the image will be returned from the cache directly without loading it from the file or creating a new instance.

Note that if SetImage has been previously called with a null object for the image parameter, then this method will return null as well.

In all cases, the returned RasterImage object is not used by this Document, the user is responsible for deleting it using RasterImage.Dispose after it has been used.

If the value of ImageScale is a value greater than 1, then the result raster image will have a size that is equal to Size / ImageScale.

The LEADTOOLS Document Viewer uses this method to obtain the raster image for the page when the view mode is "Raster Image".

The LEADTOOLS Document Converter uses this method to obtain the raster image for the page when converting using OCR or when adding the overlay image of a page if needed.

Refer to Loading Using LEADTOOLS Documents Library for more information.

Example

For an example, refer to DocumentPage.

Requirements

Target Platforms

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