Represents the pages of an OCR document object.
IOcrPageCollection holds the pages currently added into an OCR document (IOcrDocument). IOcrDocument through the IOcrDocument.Pages holds a collection of IOcrPage object. Each of these IOcrPage objects contains the raster image used to create it (the image used when the page is loaded or added) and a group of OCR zones for the page either added manually or through auto-zoning.
In memory-based IOcrDocument, the IOcrPageCollection holds the pages. The user can recognize any or all of the pages at any time and pages can be added or removed at will.
In file-based IOcrDocument, the IOcrPageCollection is a store-only view of the pages. when page is added, a snap shot of the current recognition data is saved into the document. This data cannot be modified anymore and the page is no longer needed. The user must recognize the pages before they are added to the document and pages can only be added but not removed. In this mode, you can only use IOcrPageCollection.Add and IOcrPageCollection.Count. No other method or property is supported.
The IOcrPageCollection interface implements standard .NET ICollection<T>, IList<T>, and IEnumerable<T> interfaces and hence, you can use the member of these interfaces to add, remove, get, set and iterate through the different pages of the OCR document (if the document is memory-based).The following list contains the major functionality of the IOcrPageCollection interface of a memory-based document:
Add new pages to an OCR document from raster image files. These files can be in disk files, a .NET stream (memory or otherwise) or even in a remote URL. The following table lists all the page addition method groups:
Methods | Description |
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AddPage | Adds a single page from a RasterImage, DIB or an image file in disk file, .NET stream, remote URL. |
AddPages | Adds multiple pages from a multipage RasterImage or an image file in disk file, .NET stream or remote URL. |
InsertPage | Inserts into a specific location a single page from a RasterImage, DIB or an image file in disk file, .NET stream, remote URL. |
InsertPages | Inserts into a specific location multiple pages from a multipage RasterImage or an image file in disk file, .NET stream or remote URL. |
Export pages from the OCR document to raster image files. You can save the pages in disk files, .NET streams or as a single or multipage RasterImage object with any of the file formats supported by LEADTOOLS. The following table list all the page exporting method groups:
Methods | Description |
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ExportPage | Saves a single page from the OCR document to a RasterImage object, an image file in disk file or a .NET stream. |
ExportPages | Saves multiple pages from the OCR document to a multipage RasterImage object, an image file in disk file or a .NET stream. |
Perform auto image preprocessing on a single or multiple pages in the OCR document through AutoPreprocess. These methods provide a shortcut for iterating through the pages in the collection and calling IOcrPage.AutoPreprocess on each page.
Only the following members are supported in file-based documents:
Add: Adds an IOcrPage to the document by taking a snapshot of its correct recognition data.
Count: Gets the number of pages in the document.
The LEADTOOLS OCR engine supports pages of dots per inch (DPI) values of 150 and greater. If you try to add a page with a DPI of less than 150 then the engine might be able to recognize any data from this page.
This example will load multiple-pages into an OCR document and saves the OCR result into a multiple-page PDF file.