Convert PJPEG to PBM

The PJPEG (Progressive JPEG) is a file extension for images that enhances the standard JPEG format by displaying images in successive waves of increasing detail, improving the user experience during slow network conditions. The JPEG stands for "Joint Photographic Experts Group", the organization that developed the standard in 1992. PJPEG is particularly useful for web applications, as it allows images to appear more quickly and progressively refine in quality, rather than loading from top to bottom like baseline JPEGs.

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.