Free webp to jpg
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Image MIME Reference
Sealed-PNG

SealedMedia Portable Network Graphics

image/vnd.sealed.png
VS

Sony Alpha Raw Image

image/x-sony-arw
Sony-ARW

A complete technical comparison of SealedMedia Portable Network Graphics and Sony Alpha Raw Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature Sealed-PNG Sony-ARW
Transparency (Alpha) ✕ No ✕ No
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support ✕ No Yes
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
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)
Full Sealed-PNG reference →
Sony Alpha Raw Image
image/x-sony-arw
Extension
.arw
Container TIFF-based (Proprietary)
Compression Uncompressed / Lossless Compressed / Lossy Compressed
Algorithm
NoneSony Proprietary LosslessSony Proprietary Lossy
Color Depth 12-bit (Per Channel), 14-bit (Per Channel)
Developed by Sony Corporation
Released 2006
Magic Bytes
49 49 2A 00
Full Sony-ARW reference →

Browser Support Comparison

Browser Sealed-PNG Sony-ARW
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕ ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
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
Sony-ARW

Sony-ARW Strengths

  • Retains absolute maximum sensor data, enabling massive shadow recovery and highlight protection compared to compressed in-camera JPEGs
  • Embeds high-quality JPEG previews and robust metadata, allowing photographers to match in-camera color science (like Creative Looks) perfectly during raw processing
  • Utilizes the standard TIFF container structure, ensuring broad compatibility with open-source decoding libraries (like LibRaw)
Limitations
  • Proprietary format means it requires constant updates to raw processing engines every time Sony releases a new camera model
  • Sony's historically controversial lossy compression algorithm (often called 'star eater' due to spatial filtering artifacts) was a drawback for astrophotography in older ARW versions, though largely resolved in newer models with uncompressed/lossless options
  • Cannot be directly embedded into web pages or used in standard HTML/CSS contexts

When to choose which format

Sealed-PNG
Use Sealed-PNG when…
  • Enterprise Information Rights Management (IRM)
  • Secure Corporate Intellectual Property Distribution
  • Revocable Medical or Legal Imaging
Sony-ARW
Use Sony-ARW when…
  • Professional Digital Photography
  • Non-destructive Image Post-Processing
  • High Dynamic Range (HDR) Imaging Archival

More comparisons

Sealed-PNG vs ACES → Sony-ARW vs ACES → Sealed-PNG vs APNG → Sony-ARW vs APNG → Sealed-PNG vs AVCI → Sony-ARW vs AVCI → Sealed-PNG vs AVCS → Sony-ARW vs AVCS → Sealed-PNG vs AVIF → Sony-ARW vs AVIF → All comparisons →
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