That extension becomes active when a directory (and not a file), which only contains files with the JPG or JPEG filename extension, is indicated as the main file.

It makes it possible to create a publication which will be displayed by the reader application with the use of a special extension which facilitates viewing images (for example, navigating among images, enlarging them, and moving them) – see the image below.

Once the extension has been activated, there opens a window in which the user can enter additional information about images (see the image below). On the left side of the window, there is a file list. The file order on the list can be changed by selecting an image and clicking the “Up” or “Down” buttons. On the right, there are fields for additional information about the selected file: a description and a comment which can be displayed in the reader application.

Once the files have been put in the proper order and all data about the files have been entered, the user should click the “Confirm” button to finish the creation of the JPG publication (if the user clicks the “Cancel” button, the directory with JPG files will be handed over to another file-processing extension, usually the window for selecting the main file from all the files in the directory). As a result, a PresentationData.xml file will be created and marked as the main file. It is a simple XML file which contains all the information needed fro displaying images in the reader application.