Convert otb to pnm

What is the difference between .otb and .pnm?

Description: The OTB (Nokia Over The Air Bitmap Image) file format is a type of image file developed for use on Nokia mobile devices. These files are specifically optimized for efficient transmission and display on Nokia phones, particularly older models. The OTB format is designed to be compact to facilitate over-the-air (OTA) transmission, which was an essential feature in the era of limited bandwidth and data transfer capabilities. The format supports monochrome graphics, making it suitable for simple images like icons and logos.; The PNM (Portable Any Map Image) file format is a subset of the broader Netpbm format, designed for storing various types of digital images. It acts as an umbrella term for three specific types of grayscale, color, and black-and-white images, represented by PBM (Portable Bitmap), PGM (Portable Graymap), and PPM (Portable Pixmap) formats respectively. PNM files are known for their simplicity and ease of conversion to other image formats.