Convert PBM to SIX

The PBM (Portable Bitmap) file extension, part of the Netpbm project, originated in the late 1980s to facilitate efficient and portable graphics file interchange. Primarily, PBM files are used to store monochrome bitmaps in a simple ASCII text format, ensuring easy compatibility across different systems and platforms. This format supports only black-and-white imagery, making it particularly useful in scenarios where simplicity and minimalism are prioritized, such as in Unix environments for bitmap manipulation and transfer. Its historical significance lies in promoting a standardized approach to bitmap graphics in early computer technology.

The SIX file extension, short for "six pixels", is a bitmap graphics format developed by Digital Equipment Corporation (DEC) for their terminals and printers. Introduced initially to send bitmap graphics to DEC dot matrix printers like the LA50, SIX later facilitated the transfer of soft fonts to terminals such as the VT220. This format encodes images using a series of six-pixel-high patterns, making it efficient for transmitting graphics over 7-bit serial links. Rediscovered around 2010, SIX remains in use with modern terminal emulators for tasks like video playback.