Digital Negative

Last updated
Digital Negative (DNG)
DNG tm.svg
Filename extension
.dng & .DNG
Internet media type image/x-adobe-dng, image/x-raw-adobe, image/DNG
Developed by Adobe Systems
Initial releaseSeptember 27, 2004;20 years ago (2004-09-27)
Latest release
1.7.1.0
September 2023;1 year ago (2023-09)
Type of format Raw image format
Container for Metadata may be embedded in XMP, Exif or IPTC formats.
Extended from TIFF/EP
Open format?Yes
Website helpx.adobe.com/photoshop/digital-negative.html

Digital Negative (DNG) is an open, lossless raw image format developed by Adobe and used for digital photography. It was launched on September 27, 2004. [1] The launch was accompanied by the first version of the DNG specification, [2] plus various products, including a free-of-charge DNG converter utility. All Adobe photo manipulation software (such as Adobe Photoshop and Adobe Lightroom) released since the launch supports DNG. [3]

Contents

DNG is based on the TIFF/EP standard format, and mandates significant use of metadata. The specification of the file format is open and not subject to any intellectual property restrictions or patents. [4]

Rationale for DNG

Adobe states that, given the existence of a wide variety of camera-brand-specific raw image formats, it introduced DNG as a standardized and backward-compatible universal file format. [5] It is based on the TIFF 6.0 standard. [6] Various professional archivists and conservationists, working in institutional settings have adopted DNG for archival purposes. [7] [8] [9] [10] [11] [12] [13] [14] [15]

Objectives

The objectives of the DNG file format are: [1] [16] [17] [18]

Digital image preservation (sometimes known as "archiving")
The US Library of Congress states that DNG is a recommended alternative to other raw image formats. [19] The Digital Photography Best Practices and Workflow (dpBestflow) project, funded by the United States Library of Congress and run by the American Society of Media Photographers (ASMP), singles out DNG, and states "DNG files have proven to be significantly more useful than the proprietary raw files in our workflow". [20]
Easy and/or comprehensive exploitation by software developers
Software could support raw formats without DNG, by using reverse engineering and/or dcraw; but DNG makes it easier, and many software products can handle, via DNG, images from cameras that they have no specific knowledge of, [21] however, any settings stored in the DNG file by software from one company are unlikely to be recognized by a product from a different company.
In-camera use by camera manufacturers
About 12 camera manufacturers have used DNG in-camera. About 38 camera models have used DNG. [22] Raw image formats for more than 230 camera models can be converted to DNG. [23]
Multi-vendor interoperability
Unlike the proprietary RAW formats used by most cameras, DNG is supported by multiple vendors, and is readable by a multitude of software applications.

Technical summary

A DNG file always contains data for one main image, plus metadata, and optionally contains at least one JPEG preview. [2] It normally has the extension "dng" or "DNG".

DNG conforms to TIFF/EP and is structured according to TIFF. DNG supports various formats of metadata (including Exif metadata, XMP metadata, IPTC metadata) and specifies a set of mandated metadata. [24]

DNG is both a raw image format and a format that supports "non-raw", or partly processed, images. [2] The latter (non-raw) format is known as "Linear DNG". [25] Linear DNG is still scene-referred [26] and can still benefit from many of the operations typically performed by a raw converter, such as white balance, the application of a camera color profile, HDR compositing, etc. All images that can be supported as raw images can also be supported as Linear DNG. Images from the Foveon X3 sensor or similar, hence especially Sigma cameras, can only be supported as Linear DNG.

DNG can contain raw image data from sensors with various configurations of color filter array (CFA). These include: conventional Bayer filters, using three colors and rectangular pixels; four-color CFAs, for example the RGBE filter used in the Sony Cyber-shot DSC-F828; rectangular (non-square) pixels, for example as used in the Nikon D1X; and offset sensors (for example with octagonal pixels) such as Super CCD sensors of various types, as used in various Fujifilm cameras. (Or combinations of these if necessary). DNG specifies metadata describing these individual parameters; this is one significant extension to TIFF/EP.

When used in a CinemaDNG movie clip, each frame is encoded using the above DNG image format. The clip's image stream can then be stored in one of two formats: either as video essence using frame-based wrapping in an MXF file, or as a sequence of DNG files in a specified file directory.

Contrary to its name (Digital Negative) the DNG format doesn't distinguish negative and positive data [2] - all data is considered to be describing a positive image. While this is not an issue when working with images from digital cameras (which are always positive), working with scanned (by a film scanner or DSLR copy stand) film negatives saved as raw DNG files is complicated, because the resultant image is not automatically inverted and thus impossible to be used directly. A way to get around this is using an inverted curve in the photo editing application, however this reverses the effect of the image controls (Exposure, Shadow and Highlight details, etc.) which complicates the photo editing.

Timeline

This provides a mixture of the dates of significant events (such as "the first X") and various counts of usage at the anniversaries of the launch (each 27 September).

Counts of products and companies that use DNG in some way are provided primarily for illustration. They are approximate, and include products that are no longer sold. The purpose is mainly to demonstrate that such products and companies exist, and to show trends. Convertible raw image formats (camera models whose raw images can be converted to DNG) only include official support by Adobe DNG converters; not unofficial support by Adobe products (sometimes reaching about 30), nor support by other DNG converters. [23]

During the first 5 years when about 38 camera models were launched that wrote DNG, Adobe software added support for about 21 Canon models, about 20 Nikon models, and about 22 Olympus models.

Reception

The reaction to DNG has been mixed. [23] A few camera manufacturers stated their intention to use DNG at launch. They first supported DNG about 9 months after launch. Several more niche and minority camera manufacturers added support after this (e.g. Leica). The largest camera manufacturers have apparently never indicated an intention to use DNG (e.g. Nikon and Canon).[ citation needed ]

Some software products supported DNG within 5 months of launch, with many more following. Some only support DNG from cameras writing DNG, or from cameras supported via native raw image formats.[ citation needed ]

OpenRAW was an advocacy and lobby group with the motto "Digital Image Preservation Through Open Documentation". They became opposed to DNG.

Some photographic competitions do not accept converted files, and some do not accept DNG. [33]

DNG conversion

DNG Converter DNG Converter.png
DNG Converter

"DNG conversion" refers to the process of generating a DNG file from a non-DNG image. (This is in contrast to "raw conversion", which typically refers to reading and processing a raw file, which might be a DNG file, and generating some other type of output from it). DNG conversion is one of the sources of DNG files, the other being direct output from cameras and digital backs.

Several software products are able to do DNG conversion. The original such product is Adobe DNG Converter or DNG Converter, a freely-available stand-alone utility from Adobe. [17] Other Adobe products such as the ACR plugin to Photoshop or Lightroom can also generate DNG files from other image files.

Most DNG converters are supplied by companies other than Adobe. For example:

The process of DNG conversion involves extracting raw image data from the source file and assembling it according to the DNG specification into the required TIFF format. This optionally involves compressing it. Metadata as defined in the DNG specification is also put into that TIFF assembly. Some of this metadata is based on the characteristics of the camera, and especially of its sensor. Other metadata may be image-dependent or camera-setting dependent. A DNG converter must therefore have knowledge of the camera model concerned, and be able to process the source raw image file including key metadata. Optionally a JPEG preview is obtained and added. Finally, all of this is written as a DNG file.

DNG conversion typically leaves the original raw image file intact. For safety, many photographers retain the original raw image file on one medium while using the DNG file on another, enabling them to recover from a range of hardware, software and human failures and errors. For example, it has been reported in user forums that some versions of the Adobe DNG Converter don't preserve all the raw data from raw images from some camera models. [34] [35]

Summary of products that support DNG in some way

This section summarizes other more comprehensive lists. [36] [37]

Adobe products

All raw image file handling products from Adobe now support DNG. [3] Adobe DNG Converter was utility software published by Adobe Systems on September 27, 2004. It converts different camera raw format files into the Digital Negative (DNG) standard. It also supports lossless data compression when converting. The program is free of charge. It can be downloaded at Adobe's site (for Windows [38] and macOS [39] ).

Use by camera manufacturers varies; there are about 15 camera manufacturers that use DNG, including a few that specialize in movie cameras: [22]

Some digital cameras that support DNG: [22]

Apple's iPhones and other iOS devices expose an API for third-party apps such as Halide or Lightroom CC to capture DNG images. The native Camera app processes to JPEG or HEIF by default. The iPhone 12 Pro/Pro Max and subsequent Pro and Pro Max models running iOS 14.3 or later have the option to shoot pictures in DNG natively through ProRaw. [44]

Some of the Canon cameras can shoot as DNG using additional free software CHDK.

The built-in camera function in the Adobe Lightroom Mobile app saves to DNG format.

DJI supports DNG in its middle to high-end drones. [45]

Third-party software

Support by software suppliers varies; there are of the order of 200 software products that use DNG. [36] [46]

The majority of raw handling software products support DNG. Most provide generic support, while a few support it only if it is output directly from a camera. The type of support varies considerably. There appear to be very few third-party software products that process raw images but don't support DNG. This may reflect the difficulty of discovering all of those that do not. [47]

Versions of the specification

All versions of the specification remain valid, in the sense that DNG files conforming to old versions should still be read and processed by DNG readers capable of processing later versions. DNG has a version scheme built into it that allows the DNG specification, DNG writers, and DNG readers, to evolve at their own paces. [48] Each version of the specification describes its compatibility with previous versions. [2]

1.0.0.0, published September 2004
This version accompanied the launch of DNG and related products. It was a rare, possibly unique, example of a raw image format specification published by its owner. It was adequate for representing typical images, but it had a few errors and deficiencies (specifically the lack of support of "masked pixels" and an inadvertent deviation from the JPEG specification) that required it soon to be replaced by the next version.
1.1.0.0, published February 2005
This version corrected the flaws in the first version. It has proved capable of representing raw images for a large variety of cameras (both when written in-camera or via conversion from other raw image formats) for a few years, and it is the version still typically written in-camera.
1.2.0.0, published May 2008
This version was based on experience and feedback from other companies about DNG since its launch. It introduced many new features, especially several new options for color specification under the general heading of "Camera Profiles". These are mainly of value to software products wanting their own flavor of color handling. This version permits administrative control of Camera Profiles, including calibration signatures and copyright information.
1.3.0.0, published June 2009
This version added various improvements, but the major change was to introduce "Opcodes". An Opcode is an algorithm to be applied to some or all of the image data, described in the specification, and (optionally) implemented in the product that reads and processes the DNG file. The DNG file itself holds lists of Opcodes to be executed, together with the parameters to be applied on execution. In effect, the DNG file can contain lists of "function calls" to be executed at various stages in the raw conversion process. For example, the WarpRectilinear Opcode "applies a warp to an image and can be used to correct geometric distortion and lateral (transverse) chromatic aberration for rectilinear lenses". This is an example of an algorithm that cannot be applied to the raw image data itself before it is placed into the DNG file, because it should be executed after demosaicing. There are 13 Opcodes described in this version, and each Opcode is accompanied by a specification version so that more can be added in future.
1.4.0.0, published September 2012
This version added Floating Point Image Data, Transparent Pixels, Proxy DNG Files, and additional tags. It also added SampleFormat and Predictor.
1.5.0.0, published May 2019
This version added Depth Maps and processed Enhanced Image Data that can be stored alongside the raw image, with some details of the processing performed.
1.6.0.0, published December 2021
This version added large file support (64-bit BigTIFF extension), Semantic Masks, triple-illuminant calibration profiles, and more.
1.7.0.0, published June 2023
This version adds support for JPEG XL as a compression method. [2] In September, 1.7.1.0 was published as a minor refresh with additional compression parameters.


CinemaDNG, published September 2009
CinemaDNG is a derivative of DNG with additional tags specifically for frames of movie clips (TimeCodes and FrameRate. [49] It is not clear whether these tags will be added to a later version of the DNG specification, or will remain separately described only in the CinemaDNG specification.

Standardization

DNG is not a standard format, but is based on several open formats or standards and is being used by ISO in its revision of TIFF/EP. A timeline:

Patent status

In 2004, Adobe published a "patent license" for DNG that allows everyone to exploit DNG, [55] on the condition that the licensee prominently displays text saying it is licensed from Adobe in source and documentation, and that the license may be revoked if the licensee brings any patent action against Adobe or its affiliates related to the reading or writing of files that comply with the DNG Specification. The license does not name any patent linked to DNG, however. [56]

In 2009, Adobe states that there are no known intellectual property encumbrances or license requirements for CinemaDNG, a superset of DNG. [4] Adobe also stated that if there were a consensus that DNG should be controlled by a standards body, they were open to the idea. [16] Even though the "patent license" now grants rights for no known patents, Adobe has not removed the patent license: as of August 2023, it remains on the Adobe website. [55]

See also

Related Research Articles

Tag Image File Format or Tagged Image File Format, commonly known by the abbreviations TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing, word processing, optical character recognition, image manipulation, desktop publishing, and page-layout applications. The format was created by the Aldus Corporation for use in desktop publishing. It published the latest version 6.0 in 1992, subsequently updated with an Adobe Systems copyright after the latter acquired Aldus in 1994. Several Aldus or Adobe technical notes have been published with minor extensions to the format, and several specifications have been based on TIFF 6.0, including TIFF/EP, TIFF/IT, TIFF-F and TIFF-FX.

<span class="mw-page-title-main">Exif</span> Metadata standard in digital images

Exchangeable image file format is a standard that specifies formats for images, sound, and ancillary tags used by digital cameras, scanners and other systems handling image and sound files recorded by digital cameras. The specification uses the following existing encoding formats with the addition of specific metadata tags: JPEG lossy coding for compressed image files, TIFF Rev. 6.0 for uncompressed image files, and RIFF WAV for audio files. It does not support JPEG 2000 or GIF encoded images.

Picture Transfer Protocol (PTP) is a protocol originally developed by the Photographic and Imaging Manufacturers Association (PIMA) to allow the transfer of images from digital cameras to computers and other peripheral devices without the need for additional device drivers. The protocol was standardized by the ISO in 2005. The current version of the standard is ISO 15740:2013.

The Extensible Metadata Platform (XMP) is an ISO standard, originally created by Adobe Systems Inc., for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets.

A camera raw image file contains unprocessed or minimally processed data from the image sensor of either a digital camera, a motion picture film scanner, or other image scanner. Raw files are so named because they are not yet processed, and contain large amounts of potentially redundant data. Normally, the image is processed by a raw converter, in a wide-gamut internal color space where precise adjustments can be made before conversion to a viewable file format such as JPEG or PNG for storage, printing, or further manipulation. There are dozens of raw formats in use by different manufacturers of digital image capture equipment.

JPEG XR is an image compression standard for continuous tone photographic images, based on the HD Photo specifications that Microsoft originally developed and patented. It supports both lossy and lossless compression, and is the preferred image format for Ecma-388 Open XML Paper Specification documents.

Tag Image File Format/Electronic Photography (TIFF/EP) is a digital image file format standard – ISO 12234-2, titled "Electronic still-picture imaging – Removable memory – Part 2: TIFF/EP image data format". This is different from the Tag Image File Format, which is a standard administered by Adobe currently called "TIFF, Revision 6.0 Final – June 3, 1992".

dcraw

dcraw is an open-source computer program which is able to read numerous raw image format files, typically produced by mid-range and high-end digital cameras. dcraw converts these images into the standard TIFF and PPM image formats. This conversion is sometimes referred to as developing a raw image since it renders raw image sensor data into a viewable form.

Windows Imaging Component (WIC) is a COM-based imaging codec framework introduced in Windows Vista (and later available in Windows XP Service Pack 3) for working with and processing digital images and image metadata.

<span class="mw-page-title-main">FastPictureViewer</span> Freemium image viewer for Windows

FastPictureViewer is a freemium image viewer for Windows XP and later. Its aim is to facilitate quick review, rating and annotation of large quantities of digital images in the early steps of the digital workflow, with an emphasis on simplicity and speed. As an app with a freemium license, a basic version is available cost-free for personal, non-profit or educational uses, while a commercial license is required for the professional version with additional features. The basic version starts as a full version trial.

<span class="mw-page-title-main">Pentax K20D</span> Camera model

The Pentax K20D and its clone, the Samsung GX-20, are 14.6 megapixel digital single-lens reflex cameras manufactured by Pentax that were announced on January 23, 2008. The K20D was available in the U.S. market from February 2008 through autumn 2009.

<span class="mw-page-title-main">ExifTool</span> Software

ExifTool is a free and open-source software program for reading, writing, and manipulating image, audio, video, and PDF metadata. It is platform independent, available as both a Perl library (Image::ExifTool) and command-line application. ExifTool is commonly incorporated into different types of digital workflows and supports many types of metadata including Exif, IPTC, XMP, JFIF, GeoTIFF, ICC Profile, Photoshop IRB, FlashPix, AFCP and ID3, as well as the manufacturer-specific metadata formats of many digital cameras.

The Information Interchange Model (IIM) is a file structure and set of metadata attributes that can be applied to text, images and other media types. It was developed in the early 1990s by the International Press Telecommunications Council (IPTC) to expedite the international exchange of news among newspapers and news agencies.

<span class="mw-page-title-main">RawTherapee</span> Raw photo processing software

RawTherapee is a free and open source application for processing photographs in raw image formats such as those created by many digital cameras. It comprises a subset of image editing operations specifically aimed at non-destructive post-production of raw photos and is primarily focused on improving a photographer's workflow by facilitating the handling of large numbers of images. It is notable for the advanced control it gives the user over the demosaicing and developing process. It is cross-platform, with versions for Microsoft Windows, macOS and Linux.

In digital photography, the Camera Image File Format (CIFF) file format is a raw image format designed by Canon, and also used as a container format to store metadata in APP0 of JPEG images. Its specification was released on February 12, 1997.

<span class="mw-page-title-main">CinemaDNG</span>

CinemaDNG is the result of an Adobe-led initiative to define an industry-wide open file format for digital cinema files. CinemaDNG caters for sets of movie clips, each of which is a sequence of raw video images, accompanied by audio and metadata. CinemaDNG supports stereoscopic cameras and multiple audio channels. CinemaDNG specifies directory structures containing one or more video clips, and specifies requirements and constraints for the open format files,, within those directories, that contain the content of those clips.

<span class="mw-page-title-main">OpenRAW</span>

OpenRAW was an initiative to raise awareness of a serious problem with top-end digital photography and to help solve that problem. The problem concerns long-term access and viewing of the raw images often used by professional and experienced amateur photographers. OpenRAW's solution was "Digital Image Preservation Through Open Documentation".

This article presents a comparison of image viewers and image organizers which can be used for image viewing.

High Efficiency Image File Format (HEIF) is a digital container for storing individual digital images and image sequences. The standard covers multimedia files that can also include other media streams, such as timed text, audio and video.

References

  1. 1 2 3 "Adobe Unifies Raw Photo Formats with Introduction of Digital Negative Specification" (Press release). Adobe Systems. September 27, 2004. Archived from the original on August 21, 2014. Retrieved August 20, 2014.
  2. 1 2 3 4 5 6 7 8 Digital Negative (DNG) Specification (PDF), Adobe.
  3. 1 2 Pearson, Barry, Adobe products that support DNG, UK, archived from the original on 2023-05-14, retrieved 2009-09-20.
  4. 1 2 "File Format", CinemaDNG, Adobe Labs, 2009, archived from the original on 2012-04-03.
  5. ""Digital Negative (DNG)"" . Retrieved 2022-07-28.
  6. ""Adobe Digital Negative Converter"" . Retrieved 2022-07-28.
  7. universal photographic digital imaging guidelines (UPDIG): File formats - the raw file issue
  8. Archaeology Data Service / Digital Antiquity: Guides to Good Practice - Section 3 Archiving Raster Images - File Formats
  9. University of Connecticut: "Raw as Archival Still Image Format: A Consideration" by Michael J. Bennett and F. Barry Wheeler
  10. Inter-University Consortium for Political and Social Research: Obsolescence - File Formats and Software
  11. JISC Digital Media - Still Images: Choosing a File Format for Digital Still Images - File formats for master archive Archived 2011-11-16 at the Wayback Machine
  12. International Digital Enterprise Alliance, Digital Image Submission Criteria (DISC) Guidelines & Specifications 2007 (PDF) [ permanent dead link ]
  13. The J. Paul Getty Museum - Department of Photographs: Rapid Capture Backlog Project - Presentation Archived 2012-06-10 at the Wayback Machine
  14. American Institute for Conservation - Electronic Media Group: Digital Image File Formats Archived 2010-12-14 at the Wayback Machine
  15. Archives Association of British Columbia: Born Digital Photographs: Acquisition and Preservation Strategies (Rosaleen Hill) [ permanent dead link ]
  16. 1 2 3 4 "Adobe's Kevin Connor Speaks on Adobe's DNG Specification", Digital Media Designer, Digital Media net, archived from the original on 2015-12-08, retrieved 2009-09-20.
  17. 1 2 Adobe: Digital Negative (DNG) - The public, archival format for digital camera raw data
  18. Adobe: Introducing the Digital Negative Specification: Information for manufacturers
  19. Planning for US Library of Congress Collections: Preferences in Summary
  20. dpBestflow: Raw File Formats
  21. Barry Pearson: Support via DNG but not native raws
  22. 1 2 3 Barry Pearson: Products from Camera Manufacturers that support DNG in some way.
  23. 1 2 3 Barry Pearson: A brief history of DNG
  24. Adobe: DNG Specification (Section 4)
  25. Barry Pearson: Linear DNG
  26. CIE: "Scene-referred": image state, scene-referred Archived 2013-05-11 at the Wayback Machine
  27. Seitz Phototechnik: Roundshot D3 with Seitz D3 digital scan back
  28. Seitz Phototechnik: Seitz 6x17 Digital with Seitz D3 digital scan back Archived 2007-08-15 at the Wayback Machine
  29. Ikonoskop: Ikonoskop A-cam dII Archived 2010-02-02 at the Wayback Machine
  30. Zeiss: PhotoScope 85 T* FL
  31. Ricoh: Ricoh GXR Archived 2016-06-22 at the Wayback Machine
  32. Ikonoskop: Ikonoskop A-cam3D Archived 2010-08-13 at the Wayback Machine
  33. Wadleigh, John (Oct 30, 2009). "Competition does not accept DNG" . Retrieved 3 January 2015.
  34. Adobe-hosted User Forum: Reconvert with new DNG Converter?
  35. DPReview Forum: PROGRESS: version 0.9.0.0 now supports PEF files
  36. 1 2 Adobe: DNG hardware and software support
  37. Barry Pearson: Products that support DNG in some way Archived 2012-02-25 at the Wayback Machine
  38. "MS Windows product download", DNG converter, Adobe.
  39. "Apple Mac product download", DNG converter, Adobe.
  40. "Camera app makers tap into RAW power with iOS, and look forward to dual lenses" . Retrieved 29 May 2018.
  41. "Ricoh GXR", DPReview (quick review).
  42. Round shot, CH, archived from the original on 2007-08-15, retrieved 2007-07-31.
  43. "Sigma Firmware Update Adds DNG RAW Support to sd Quattro Cameras". petapixel.com. 5 April 2017. Retrieved 2019-04-22.
  44. "About Apple ProRAW". Apple Support. Retrieved 2024-10-03.
  45. Support, D. J. I. (2017-08-24). "JPEG vs RAW - What's the difference?". DJI Guides. Retrieved 2021-07-07.
  46. Barry Pearson: Software products that support DNG in some way
  47. Barry Pearson: Products without explicit DNG support
  48. Barry Pearson: Version control in DNG files
  49. Adobe Labs: CinemaDNG - Image Data Format Specification (Version 1.0.0.0) (PDF)
  50. Barry Pearson: DNG's relationship to standards
  51. dpreview staff (May 15, 2008), "Adobe seeks International recognition for DNG", DPReview, retrieved December 11, 2014, Adobe is submitting its DNG 'universal RAW' format to the International Standard's Organization (ISO), in a move aimed at increasing acceptance and usage. The format is being proposed as part of ISO's TIFF/EP (electronic photography), standard..
  52. A member of the ISO TC42 (technical committee for photography) working group 18 (electronic imaging) standards group (26 April 2007), Digikam-devel (archive) (mailing list){{citation}}: CS1 maint: numeric names: authors list (link).
  53. "ISO 12234 Part 2 – TIFF/EP", Eye on standards (working group report), I3A (International Imaging Industry Association), down a bit, October 2008, archived from the original on 2008-10-23.
  54. Minutes of ISO/TC 130/WG2, 39th Meeting (PDF), Peking, China: NPES, September 2009, 14f, archived from the original (PDF) on 2012-01-11, retrieved 2009-11-06.
  55. 1 2 "Specification Patent License", Digital Negative (DNG), Adobe, 2005
  56. "Digital Negative (DNG)". Adobe Systems Incorporated. Retrieved 2018-07-30.