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.
PCX is one of the first bitmap image formats developed by ZSoft for the PC Paintbrush program. This is the original bitmap format for the DOS / Windows platform. It supports monochrome single-bit black and white images, an eight-bit gray scale, indexed color images, and full-color 24-bit RGB model images. But there is no support for additional color and alpha channels, clipping paths, color management. The format provides for the application of the simplest compression algorithm (RLE) so that information is not lost. Now it has a purely historical significance. The PCX file format has been replaced by newer image formats. However, the format is still used in separate applications in order to scan and send faxes. PCX multi-page fax documents use the .DCX extension. Most DOS-based programs are suitable for viewing PCX (PC eXchange) files. In particular, the viewer Norton Commander. The big drawback of the PCX format is that it has too many versions. This can be explained by the fact that the PCX standard is open, and therefore it has been widely used by most independent software developers. And therefore it is constantly updated.