In an effort to avoid potential threats caused by certain file formats used for saving images, images included in the xHTML document may only be saved in the following formats:
PNG
GIF
SVG
JPG/JPEG
If an image of a different format is included within your ESEF file, you will get the error message Violation: “imageFormatNotSupported” when your file is validated. Refere to ESMA Reporting manual, guidance 2.5.1 for extra information regarding this topic.