Convert APNG (Animated PNG) to FLIF

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 Free Lossless Image Format (FLIF) is a lossless image compression format designed to outperform other formats like PNG, lossless WebP, and JPEG 2000 in terms of compression ratio. Introduced in 2015, FLIF uses MANIAC (Meta-Adaptive Near-zero Integer Arithmetic Coding) for efficient compression, making it suitable for various image types without quality loss. Despite its advantages, FLIF development ceased as it was superseded by JPEG XL.