This is a format for presenting fonts in PDF files that was initially conceived to store symbols in the Japanese and Chinese languages because it had a 16-bit structure and allowed for more precise adjustment. CID expands the the potential for PostScript by supporting languages that do not have a left-to-right orientation, and by supporting even a vertical mode of orientation.
This bitmap image format was created for storing images taken in HDR mode, which provides a high dynamic contrast ratio. It may have either a 32- or 16-bit pixel structure. It is used for high-quality graphics with rich bitmap images, with or without lossy compression.