Free webp to jpg
EN
Image MIME Reference
JPEG-AI-Sequence

JPEG AI Image Sequence

image/jais
VS

MacPaint Image

image/x-macpaint
MacPaint

A complete technical comparison of JPEG AI Image Sequence and MacPaint Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature JPEG-AI-Sequence MacPaint
Transparency (Alpha) Yes ✕ No
Animation Support Yes ✕ No
Progressive Loading Yes ✕ No
HDR Support Yes ✕ No
EXIF Metadata Yes ✕ No
ICC Color Profile Yes ✕ No
JPEG AI Image Sequence
image/jais
Extension
.jais
Container ISOBMFF / HEIF Image Sequence
Compression Lossy (Variational Autoencoder / Neural Network)
Algorithm
Deep Neural Network (Variational Autoencoder with Hyperpriors)
Color Depth 8-bit, 10-bit, 12-bit, 16-bit, Wide-gamut & HDR
Developed by Joint Photographic Experts Group (ISO/IEC JTC 1 / ITU-T)
Released 2025
Magic Bytes
.. .. .. .. 66 74 79 70 6A 61 69 73 (Size + ftypjais)
Full JPEG-AI-Sequence reference →
MacPaint Image
image/x-macpaint
Extension
.mac.pntg.pnt.macp
Container Raw pixel payload with a 512-byte pattern header
Compression PackBits (Run-Length Encoding)
Algorithm
PackBits (Apple RLE)
Color Depth 1-bit (Monochrome)
Developed by Apple Computer, Inc. (Bill Atkinson)
Released 1984
Magic Bytes
None (Relies on classic Mac OS 'PNTG' OSType)
Full MacPaint reference →

Browser Support Comparison

Browser JPEG-AI-Sequence MacPaint
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕ ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
JPEG-AI-Sequence

JPEG-AI-Sequence Strengths

  • Extends the state-of-the-art compression efficiency of JPEG AI to multi-frame image sequences and short animations
  • Allows machine vision algorithms to process temporal sequences (like surveillance bursts) directly in the compressed latent domain, saving immense computational power
  • Utilizes the robust, industry-standard ISOBMFF container for metadata, timing, and multi-track encapsulation
Limitations
  • Lacks native decoding support in current web browsers, operating systems, and video players
  • Decoding neural-network-compressed sequences requires significant compute overhead on hardware lacking dedicated AI accelerators (NPUs/GPUs)
  • Adoption is hindered by competition with established sequence formats like AVIF, HEVC (HEICS), and modern video codecs
MacPaint

MacPaint Strengths

  • Profoundly historically significant as the format that introduced millions to the concept of bitmap digital painting
  • Extremely simple PackBits compression makes it easy for emulator developers or archivists to write parsers from scratch in under an hour
Limitations
  • Severely limited: strictly black and white, and hard-locked to exactly 576 x 720 pixels
  • Lack of standard magic bytes makes programmatic file sniffing unreliable on modern filesystems without relying on the file extension
  • Completely obsolete and unsupported by modern web browsers or consumer image viewers

When to choose which format

JPEG-AI-Sequence
Use JPEG-AI-Sequence when…
  • Machine Vision and AI Video/Burst Workflows
  • Cloud Storage Animation Optimization
  • Focal Stacks and Medical Volumetric Slices
  • Visual Surveillance Sequences
MacPaint
Use MacPaint when…
  • Historical Apple Macintosh Archival
  • Early 1980s Digital Art Preservation
  • Retro UI/UX Academic Research

More comparisons

JPEG-AI-Sequence vs ACES → MacPaint vs ACES → JPEG-AI-Sequence vs APNG → MacPaint vs APNG → JPEG-AI-Sequence vs AVCI → MacPaint vs AVCI → JPEG-AI-Sequence vs AVCS → MacPaint vs AVCS → JPEG-AI-Sequence vs AVIF → MacPaint vs AVIF → All comparisons →
Share this comparison