Convert APNG (Animated PNG) to SIX

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 SIX file extension, short for "six pixels", is a bitmap graphics format developed by Digital Equipment Corporation (DEC) for their terminals and printers. Introduced initially to send bitmap graphics to DEC dot matrix printers like the LA50, SIX later facilitated the transfer of soft fonts to terminals such as the VT220. This format encodes images using a series of six-pixel-high patterns, making it efficient for transmitting graphics over 7-bit serial links. Rediscovered around 2010, SIX remains in use with modern terminal emulators for tasks like video playback.