JPM is a JPEG2000 bitmap category file format. The JPEG 2000 Part 6 standard defines that the .jpm extension refers to the JPEG 2000 Composite Image File Format. The JPEG2000 graphic format is a new standard that appeared in 2000 as an update to the JPEG format. He uses a type of technology called wavelet compression, which provides the best ratio of size and quality. The JPM format (i.e., the JPEG 2000 Multi-layer Image Format, ISO 15444-6) was developed for documents that have multiple pages and can be processed as a multi-page photo converter. The purpose of the JPEG 2000 Part 6 composite image format is to work primarily with documents and facsimile images. Compared to regular JPEG 2000 images, a .jpm file is a composite image with many layers. This file can have many pages. Moreover, each such page can have several raster objects. Moreover, in different encodings (JPEG, JPEG 2000, JBIG). They are located in a certain way and make up a single whole. JPM files are used as “digital originals” that store scanned copies of documents and other images and / or texts.
JNG is a raster format. It has a close relationship with PNG. The JNG format uses exactly the same structure as PNG. It stores data in the main JPEG stream, is able to store the alpha channel stream in the form of PNG or JPEG, as well as information in the form of text. It also supports gamma and color correction. This image file format uses lossless compression similar to standard .JPEG files. The format was developed as a sub-format for .MNG objects. However, it is quite suitable as a separate raster image format. Some JNG files include an optional alpha channel for transparency. It does not support standard JPEG files. It is also possible to include auxiliary data sections, which may contain information about color space and comments. JNG is a format that is not very popular. Nevertheless, it has such a very good property as a large degree of lossy graphics compression. He also has an alpha channel. Color data is stored in JPEG format. For alpha, there is one of two storage options. It can be compressed using JPEG, like a grayscale picture. Or you can use the same as in PNG, lossless compression. The format is best suited to store texture atlases in mobile games. A good win for a mobile game.