Image MIME Reference
PSD
Adobe Photoshop Document
image/vnd.adobe.photoshop
VS
SealedMedia Portable Network Graphics
image/vnd.sealed.png
Sealed-PNG
A complete technical comparison of Adobe Photoshop Document and SealedMedia Portable Network Graphics — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | PSD | Sealed-PNG |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | Yes | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | Yes | ✕ No |
| EXIF Metadata | Yes | ✕ No |
| ICC Color Profile | Yes | ✕ No |
Adobe Photoshop Document
image/vnd.adobe.photoshop
Extension
.psd.psb.pdd
Container
Adobe Photoshop Document (PSD/PSB)
Compression
Uncompressed / RLE (Run-Length Encoding) / ZIP
Algorithm
RLEZIP (with or without prediction)None
Color Depth
1-bit (Bitmap), 8-bit, 16-bit, 32-bit (Float/HDR)
Developed by
Adobe Systems
Released
1990
Magic Bytes
38 42 50 53
SealedMedia Portable Network Graphics
image/vnd.sealed.png
Extension
.spng.sealed-png
Container
SealedMedia / Oracle IRM Wrapper
Compression
Encrypted Payload (Deflate)
Algorithm
AES EncryptionDeflate (Internal PNG payload)
Color Depth
Encrypted Payload
Developed by
SealedMedia (Acquired by Oracle Corporation)
Released
Late 1990s / Early 2000s
Magic Bytes
Unknown (Proprietary SealedMedia Container)
Browser Support Comparison
| Browser | PSD | Sealed-PNG |
|---|---|---|
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
|
|
✕ | ✕ |
PSD
PSD Strengths
- The undisputed global standard for layered raster graphics and non-destructive image editing
- Supports incredibly complex compositions combining raster data, vector shapes, live text, and adjustment layers
- Full support for advanced color spaces (CMYK, Lab, multi-channel) and 32-bit floating-point HDR workflows
Limitations
- Proprietary format: while the specification is published, complete feature-parity is rarely achieved by third-party software (e.g., smart objects and complex layer styles often break)
- Files can reach enormous sizes (gigabytes) due to the preservation of unflattened, high-resolution layer data
- Zero support for native rendering in web browsers or standard mobile image viewers
Sealed-PNG
Sealed-PNG Strengths
- Provided absolute control over intellectual property, allowing enterprise administrators to instantly revoke viewing rights of a local file globally
- Detailed audit trails tracked exactly who opened the image, when, and from what IP address
Limitations
- Completely proprietary and relies on a central authentication server; if the server goes offline, the image is permanently inaccessible
- No support in modern operating systems, web browsers, or standard image editing software without installing heavy enterprise DRM clients
- Oracle effectively deprecated the IRM product line, leaving legacy sealed documents difficult to recover
When to choose which format
PSD
Use PSD when…
- Professional Photo Retouching
- Digital Painting and Illustration
- UI/UX Design Workflows
- Graphic Design and Print Production
Sealed-PNG
Use Sealed-PNG when…
- Enterprise Information Rights Management (IRM)
- Secure Corporate Intellectual Property Distribution
- Revocable Medical or Legal Imaging