Query an Image File

ImagXpress® provides the ability to query and modify images without loading them into ImagXpress.

The images may be remote or local, but may not have an HTTP or FTP address.

Query Image from File, Buffer, or Stream

Querying enables the user to gain information about the file before choosing to load or process it using ImagXpress. For example, the user may decide to load only images that are smaller than a threshold size, or images that are of a specified type. Querying is accomplished using methods within the ImageX class.

The QueryFile methods enable the user to obtain information about a specified page in a TIFF file. These methods return the ImageXData associated with the file. To query from buffer or stream, use the QueryBuffer or QueryFromStream methods.

The NumPages method enables the user to query a multiple page TIFF or DCX file to determine the number of pages in the file. This enables a user to query multiple pages, by iterating the page number in the ImageX.QueryFile methods.

Modify Image Files

Using ImagXpress (ImageX class), the user can make page-level modifications to TIFF files without loading the file. This enables the user to clean up or reduce the image size prior to loading.

The CompactFile method removes unused pages from the specified TIFF file.
The DeletePage and InsertPage methods delete/insert a specified page in the specified TIFF file.
The NumPages method enables the user to query a multiple page TIFF or DCX file to determine the number of pages in the file. This enables a user to delete or insert multiple pages in a TIFF file, by iterating the page number in the ImageX.DeletePage and ImageX.InsertPage methods.
ImagXpress enables users to set and get tags for TIFF and EXIF images without loading the image data, using the ReadAllMetaData and SaveAllMetaData methods.

Once an image is loaded into an ImageX object, the ReadAllMetaData and SaveAllMetaData methods do NOT update the ImageX object's image. Only the image at the specified filename is modified. To modify tags of an image loaded in an ImageX object, use the ImageX.Tags property.

These methods are only applicable to images stored in file, not for images in buffer or stream.