Convert PNM to ICB

The PNM (Portable Anymap) file extension, developed by Jef Poskanzer in the 1980s, stands for Portable Any Map. It is an uncompressed raster graphics format designed for portable image storage and exchange, encompassing three sub-formats: PBM (Portable Bitmap), PGM (Portable Graymap), and PPM (Portable Pixmap). PNM files store image data in plain text or binary format, ensuring easy usage across different platforms and applications. This format is widely supported by various image editing software and is valued for its simplicity and lossless compression.

The ICB file extension, associated with Targa Graphics, stands for Image Capture Board. It was originally used with the AT&T EPICenter Image Capture Board video card and software like ICB-PAINT and TARGA-PAINT. This format is a raster graphics file used for storing and exchanging deep-pixel images, supporting 8, 16, 24, and 32 bits per pixel. Developed by Truevision Inc., it played a significant role in early computer graphics for high-color display on IBM-compatible PCs.