FileOffsetUse Property

Description

Gets and sets the behavior of the FileOffset property when loading a TIFF file.

Property Type

Read-write property

Syntax

Visual Basic
Public Property FileOffsetUse As enumFileOffsetUse

Return Type

An enumFileOffsetUse value which determines the behavior of the FileOffset when loading.

Remarks

Use this property to change the behavior of the FileOffset property when reading TIFF files or custom TIFF files.

When FileOffsetUse is set to default (FO_IMAGE), the FileOffset property points to the offset in the file or memory buffer where ImagXpress will begin reading a TIFF.

When FileOffsetUse is set to FO_TIFFII or FO_TIFFMM, the file loaded with ImagXpress must be a partial TIFF starting at an IFD. The Fileoffset property tells ImagXpress where this IFD is located in a whole TIFF file. The actual TIFF page image (and tag data) must follow someplace after the IFD and not before. Normally, The type of TIFF file (Intel or Motorola) is determined by examining the beginning of the TIFF file, since this is not available with just a partial TIFF, it must be specified. Use FO_TIFFII for Intel and FO_TIFFMM for Motorola.
When FileOffsetUse is set to FO_UNKNOWN, the file loaded with ImagXpress is an entire TIFF file. The FileOffset property tells ImagXpress where the IFD to be loaded is located. This can greatly increase the speed of loading a page in a TIFF that has a large number of pages (100+). If the offset of the page is known, you can use this property to avoid searching through the entire file to load the requested page.

If the PageNbr property is used, page 1 is the IFD/page being loaded, page 2 is the second page after the IFD/page being loaded and so on.