Convert APNG (Animated PNG) to PNM

Animated Portable Network Graphics (APNG) is an extension of the Portable Network Graphics (PNG) format designed to support animated images. Introduced in 2004, APNG allows for animated sequences while retaining backward compatibility with non-animated PNG files. This format is utilized for its lossless compression, making it ideal for web graphics where image quality is paramount. APNG files are widely used for animated icons, logos, and other elements that benefit from high-quality animations without the artifacts common in GIF files. Its concise, efficient structure makes it a preferred choice among developers and designers focused on optimizing web performance.

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.