Image MIME Reference
DWG
AutoCAD Drawing
image/vnd.dwg
VS
High-Throughput JPEG 2000 Image
image/jph
HTJ2K-(JPH)
A complete technical comparison of AutoCAD Drawing and High-Throughput JPEG 2000 Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DWG | HTJ2K-(JPH) |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | Yes |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | ✕ No | Yes |
AutoCAD Drawing
image/vnd.dwg
Extension
.dwg
Container
DWG Binary Container
Compression
Proprietary Binary Compression (LZ77 based in newer versions)
Algorithm
Proprietary (Autodesk ObjectDBX)
Color Depth
Vector (True Color / Indexed AutoCAD Color Index)
Developed by
Autodesk
Released
1982
Magic Bytes
41 43 31 30 (AC10)
High-Throughput JPEG 2000 Image
image/jph
Extension
.jph
Container
JPH (ISO/IEC 15444-15)
Compression
Lossy / Lossless
Algorithm
High-Throughput JPEG 2000 (HTJ2K)
Color Depth
8-bit, 16-bit, 32-bit, 38-bit
Developed by
Joint Photographic Experts Group (JPEG)
Released
2019
Magic Bytes
00 00 00 0C 6A 50 20 20 0D 0A 87 0A ... 66 74 79 70 6A 70 68 20
Browser Support Comparison
| Browser | DWG | HTJ2K-(JPH) |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DWG
DWG Strengths
- The undisputed industry standard for 2D drafting and basic 3D CAD modeling
- Highly optimized binary structure keeps file sizes relatively small compared to text-based CAD formats like DXF
- Supports incredibly complex datasets including external references (XREFs), dynamic blocks, and extensive custom metadata
Limitations
- It is a closed, proprietary format, making it difficult for third-party developers to support fully without licensing the Open Design Alliance (ODA) SDK
- Lacks native web or standard operating system previewer support
- Format versions change frequently (roughly every 3 years), breaking backward compatibility for older CAD software
HTJ2K-(JPH)
HTJ2K-(JPH) Strengths
- Delivers orders of magnitude faster encoding and decoding than standard JPEG 2000 by utilizing a new, parallelizable block coder
- Supports mathematically lossless and lossy compression within the same codestream architecture
- Allows for resolution scalability, progressive decoding, and region-of-interest extraction without needing to decode the entire image
Limitations
- Zero native web browser support, requiring specialized libraries, API conversions, or WebAssembly (like OpenJPH.js) for web deployment
- Lack of broad consumer awareness, keeping it confined to professional, medical, and scientific workflows
- Requires more advanced software ecosystems to decode than ubiquitous formats like JPEG or WebP
When to choose which format
DWG
Use DWG when…
- Architectural Floor Plans
- Mechanical Engineering Models
- Civil Engineering Drafts
- 3D Product Designs
HTJ2K-(JPH)
Use HTJ2K-(JPH) when…
- Medical Imaging (DICOM)
- Geospatial Data
- Digital Cinema
- Professional Archiving