Remastering traditional or early digital animation is notoriously difficult. Unlike live-action film, which can be rescanned from the original 35mm negatives into 4K or 8K, early 20th-century digital animation is bound by its original rendering resolution.
The 1080p Blu-ray and digital releases generally pair the upgraded video with uncompressed DTS-HD Master Audio. This emphasizes the iconic musical score and explosive elemental sound effects. Official Remaster vs. Fan Upscales atla remastered in 1080p