JPEG format (Joint Photographic Expert Group – JPG)
JPEG is a file format commonly used for compressed images that still retain a passable quality. It's especially useful for archiving images, because JPGs take up a lot less space. It's not a good choice for image editing, however, because each tipe you open and save a JPG it is compressed. By saving it often the quality deteriorates.
Have us convert your images into JPG files.