PPM to PICON Converter

PICON (Personal Icon) is a small-format image type used in the X Window System ecosystem, developed by Steve Kinzler at Indiana University around 1990 as part of the picons (personal icons) database project. Picons are small, typically 48x48 pixel, color images used as visual identifiers for people, organizations, domains, and Usenet newsgroups in Unix mail readers, news readers, and other communication tools. The picon format is essentially an XPM (X PixMap) image stored with specific naming conventions and directory structures that allow software to look up the appropriate icon based on email address, domain name, or newsgroup name. The picons database organized thousands of these small images in a hierarchical directory structure keyed by domain name components (e.g., faces/com/example/user.xpm), enabling mail clients like exmstrstrstr and faces to automatically display a sender's photo or organizational logo alongside their messages. The system predated the modern concept of contact photos and avatars by more than a decade. One advantage is the system's pioneering role in visual identity for electronic communication: picons introduced the idea that email and Usenet messages should display a visual representation of the sender — a concept that eventually became standard in every modern email client, messaging app, and social media platform. The XPM-based format ensures that picons are displayable on any system with X Window libraries. Picon images are supported by ImageMagick, GIMP, and X Window display utilities, and the historical picons database remains archived online at Indiana University.