Adding pictures to the Picture library is a valuable way to reduce the size of your database since you can reference members of the Picture library instead of adding new instances of pictures.

By default, 4D on both Mac and Windows allows you to add only Mac picture files of type PIC or PICT. However, you are allowed to add additional picture types of common MIME types like JPEG and GIF by simply installing QuickTime.

After QuickTime is installed, you will be able to add most if not all Images to your Picture library.