ImageGear for C and C++ on Windows v19.7 - Updated
JPX Format Support
User Guide > How to Work with... > Formats with Additional Functionality > JPEG 2000 > JPX Format Support

For detailed information about the format support and control parameters, see JPX in the File Formats section.

JPEG 2000 Standard Part II defines JPX file architecture rather than a specific, fixed set of data structures that will be found in a file. The ImageGear JPEG 2000 Component provides support for the following important JPX features, which extend the JPEG 2000 format features:  

As soon as the JPEG 2000 Component is attached ImageGear Core, you can access the JPX Format Filter functionality using the Core API, in the same way as you would access functionality of other file format filters. Use the JPX filter control parameters to control the features that are specific to the JPX format. See "Using File Filter Control Parameters" in Loading and Saving for information about how to work with the filter control parameters API. See JPX in the File Formats section for the list of control parameters available for JPX format.