PageExtractMode

Specifies how resources will be copied when extracting native PDF pages.

Remarks

When splitting a PDF document, each page will be extracted either as an image or as a native PDF page, depending on how the Image Bursting and Rendering properties are configured. When a page is to be extracted as a native PDF page, this property controls which resources (fonts, bitmaps, etc.) are copied with the page - all listed resources, or only resources actually used in the drawing operators for the page.

Inside a PDF file, each page has set of drawing instructions, and a resource dictionary listing the fonts, images, and other resources needed to draw the page. When exporting a page from a PDF file, most applications blindly copy all resources listed in the page's resource dictionary to the output file, without verifying that the resources are actually used for drawing operations.

For most PDF documents this works fine, because the resource dictionary for each page lists only the resources needed to draw that page. However, in some poorly-formed PDF files, all pages share a single resources dictionary listing every resource used on every page. In this case, exporting a single page will cause every resource in the file to be exported with it, producing a file nearly as large as the original document for each page. Most desktop PDF editing tools, including Adobe Acrobat, split PDF files using this blind resource copy mechanism, which can severely bloat PDF files having this condition.

Outside of shared resource dictionaries, sometimes pages simply reference resources they don't need. For example, if a page references a font named "Font1", but has no text segments drawn using that font, it is considered an unused resource. Any large corpus of PDF documents will typically contain some percentage of wasted space due to unused resources. Forcing sparse copy for all pages can help reduce file size by eliminating random unused resources.

Can be one of the following values:

Name	Value		Description
Auto	0		Use Selective mode if two or more pages share a resource dictionary. Otherwise, use Standard mode.
Selective	1		Copy only resources which are used for drawing operations on the page.
Standard	2		Copy all resources listed in the page resource dictionary.
Disabled	255		PDF pages will not be extracted. Forces all pages to split as images.

Used By

Split Pages