JPNG - JPNG is a bespoke image file format that combines the compression benefits of JPEG with the alpha channel support of a PNG file
In iOS and Mac OS apps there is typically a choice of two image formats: PNG format allows transparency but produces large image files and is unsuited to compressing images like photographs; JPEG is great for creating small files and provides a range of compression qualities to suit the subject matter, but doesn't allow for transparency. JPNG is a new image format that combines the best of both of the other formats. JPNG is not really a format in its own right, it's a simple file wrapper that combines a JPEG and PNG image within the same file. JPEG is used to efficiently compress the RGB portion of the image and PNG is used to store the alpha channel.