Digital Negative (DNG) Specification patent license

Adobe is the publisher of the Digital Negative (DNG) Specification describing
an image file format for storing camera raw information used in a wide range
of hardware and software. Adobe provides the DNG Specification to the public
for the purpose of encouraging implementation of this file format in a
compliant manner.

This document is a patent license granted by Adobe to individuals and
organizations that desire to develop, market, and/or distribute hardware and
software that reads and/or writes image files compliant with the DNG
Specification.

Grant of rights

Subject to the terms below and solely to permit the reading and writing of
image files that comply with the DNG Specification, Adobe hereby grants all
individuals and organizations the worldwide, royalty-free, nontransferable,
nonexclusive right under all Essential Claims to make, have made, use, sell,
import, and distribute Compliant Implementations.

"Compliant Implementation" means a portion of a software or hardware product
that reads or writes computer files compliant with the DNG Specification.

"DNG Specification" means any version of the Adobe DNG Specification made
publicly available by Adobe (for example, version 1.0.0.0 dated September
2004).

"Essential Claim" means a claim of a patent, whenever and wherever issued,
that Adobe has the right to license without payment of royalty or other fee
that is unavoidably infringed by implementation of the DNG Specification. A
claim is unavoidably infringed by the DNG Specification only when it is not
possible to avoid infringing when conforming with such specification because
there is no technically possible noninfringing alternative for achieving such
conformity.

Essential Claim does not include a claim that is infringed by implementation
of (a) enabling technology that may be necessary to make or use any product or
portion thereof that complies with the DNG Specification but is not itself
expressly set forth in the DNG Specification (for example, compiler technology
and basic operating system technology), (b) technology developed elsewhere
and merely incorporated by reference in the DNG Specification, or (c) the
implementation of file formats other than DNG.

Revocation

Adobe may revoke the rights granted above to any individual or organizational
licensee in the event that such licensee or its affiliates brings any patent
action against Adobe or its affiliates related to the reading or writing of
files that comply with the DNG Specification.

Any Compliant Implementation distributed under this license must include the
following notice displayed in a prominent manner within its source code and
documentation:

"This product includes DNG technology under license by Adobe."

No warranty

The rights granted herein are provided on an as-is basis without warranty of
any kind, including warranty of title or noninfringement.

Nothing in this license shall be construed as (a) requiring the maintenance of
any patent, (b) a warranty or representation as to the validity or scope of
any patent, (c) a warranty or representation that any product or service will
be free from infringement of any patent, (d) an agreement to bring or
prosecute actions against any infringers of any patent, or (e) conferring any
right or license under any patent claim other than Essential Claims.

Reservation of rights

All rights not expressly granted herein are reserved.

Source: https://helpx.adobe.com/camera-raw/desktop/dng-and-file-formats/digital-negative.html
