Sealed-PNG

SealedMedia Portable Network Graphics

image/vnd.sealed.png Released Late 1990s / Early 2000s · by SealedMedia (Acquired by Oracle Corporation)

The image/vnd.sealed.png MIME type represents a Portable Network Graphics (PNG) file that has been encrypted and wrapped in a proprietary Digital Rights Management (DRM) container by SealedMedia (later acquired and rebranded as Oracle Information Rights Management or Oracle IRM). This format was utilized in enterprise environments to strictly control document access, track usage, and revoke viewing privileges of sensitive images even after they were downloaded by the user or distributed outside the corporate network.

Security & DRM Production Ready

Technical Specifications

MIME Type

image/vnd.sealed.png

Extensions

.spng.sealed-png

Container

SealedMedia / Oracle IRM Wrapper

Compression

Encrypted Payload (Deflate)

Algorithms

AES EncryptionDeflate (Internal PNG payload)

Color Depth

Encrypted Payload

Metadata

None

Capabilities

Transparency

Animation

Progressive Loading

Alpha Channel

HDR Support

Official Specification

Aliases: application/vnd.sealedmedia.softseal.png

Magic Bytes & HTTP Headers

File Signature (Magic Bytes)

Unknown (Proprietary SealedMedia Container)

ASCII: Unknown

HTTP Headers

Content-Type: image/vnd.sealed.png

HTML Accept Attribute

accept="None"

Browser Support Matrix

Browser	Status	Min Version
Chrome	Not Supported	—
Firefox	Not Supported	—
Safari	Not Supported	—
Edge	Not Supported	—
Internet Explorer	Not Supported	Legacy

Advantages & Limitations

Advantages

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

Developer Code Snippets

import magic
# Libmagic lacks definitions for the proprietary SealedMedia container. It will likely identify the file as 'application/octet-stream'.
print(magic.from_file('secure_image.spng', mime=True))

const mime = require('mime');
// JS MIME libraries map .spng to image/vnd.sealed.png purely based on historical IANA registry associations
console.log(mime.getType('secure_image.spng')); // Likely outputs 'image/vnd.sealed.png'

import "net/http"
// The standard net/http library cannot detect sealed files internally via byte sniffing. You must rely on extension string matching.

$mime = mime_content_type('secure_image.spng');
echo $mime; // Standard server environments will map this to application/octet-stream

File Detection Steps

How to programmatically detect a image/vnd.sealed.png file by reading its raw bytes:

1 Standard file sniffers lack magic byte definitions for the proprietary Oracle IRM/SealedMedia container wrapper.
2 Identification relies almost entirely on the .spng extension or HTTP Content-Type headers generated by the IRM distribution server.

Software Support

O

Oracle IRM Desktop

S

SealedMedia Unsealer (Legacy)

Conversion Tools

Share & Embed

Markdown Badge

[![Sealed-PNG Format](https://freewebptojpg.com/mime/image/sealed-png/badge.svg)](https://freewebptojpg.com/mime/image/sealed-png)

Interactive iframe Widget

<iframe src="https://freewebptojpg.com/mime/image/sealed-png/embed" width="100%" height="280" style="border:1px solid #cbd5e1;border-radius:8px;" title="Sealed-PNG Specs"></iframe>

JSON API

All data on this page is available as a free, open JSON API. Use it in your project, documentation, or tooling.

GET https://freewebptojpg.com/mime/image/sealed-png.json Open JSON

Free to use

No auth required

CORS enabled

Use from any domain

Cached 24h

Cache-Control headers set

Frequently Asked Questions

What is a sealed PNG (.spng) file?

A sealed PNG file is a standard PNG image that has been encrypted and encapsulated within a proprietary DRM (Digital Rights Management) shell developed by SealedMedia. It requires specialized software and authentication against an enterprise licensing server to open.

How do I open an image/vnd.sealed.png file?

You cannot open a sealed PNG with standard image viewers or web browsers. You must install the Oracle IRM Desktop client (or legacy SealedMedia Unsealer) and possess the active credentials and permissions granted by the document owner's central licensing server.

Can I convert a sealed PNG to a normal PNG?

Not directly. The file is cryptographically secured. You must first open it using the authenticated Oracle IRM client. If your permissions allow it, you may be able to copy the image or use the 'unseal' feature to export it back to an unprotected PNG format.