What is DNG format?

What is DNG format?

Common archive format of digital camera raw data

In the workflow of digital photography, the original data file format is becoming more and more popular, and it is becoming a hot fashion, because it provides more creative control space for professional creators. However, various cameras may use many different raw data formats, and the specifications of these formats are not public, which means that not every raw data file can be read by many software applications. Therefore, adopting these proprietary raw data files as a long-term archiving solution has certain risks, and it is more challenging to enjoy these files in multiple complex workflows.

Is there a solution to this increasingly prominent problem? Digital negative (DNG) is a public archive format of original data files generated by digital cameras. DNG solves the problem of lack of open standards between the original data files of different cameras, thus helping to ensure that photographers can access their files in the future.

Within one year of introducing DNG format, dozens of software vendors have developed DNG-supporting software, such as Extensis, Canto, iView and Apple. Some famous camera manufacturers, such as Hasselblad, Leica, Ricoh and Samsung, have also introduced cameras that directly support DNG. Learn more.

In addition to the digital negative specification, Adobe also provides a free Adobe DNG converter (Windows? * | Macintosh*), which can easily convert raw data files of many popular cameras today. The current DNG converter 4.3. 1 can be used as a universal binary application for Intel-based Macintosh computers. Software developers and suppliers can download the complete DNG specification (PDF, 300K). Adobe? Photoshop？ CS2, Photoshop CS, Photoshop Elements 3.0, Photoshop Elements 4.0 and Photoshop Elements 5.0 all support DNG.

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Advantages of DNG format

In September, 2004, Adobe released the file format "DNG (Digital Negative Specification)" aiming at unifying the image file format "RAW" widely used in digital SLR cameras. As the name implies, RAW is a file format that directly records the image signals output by photographic elements, which is widely used in the field of artistic photography. Usually, the image files output in RAW format cannot be automatically adjusted by popular digital cameras for white balance and sharpness.

What is DNG format?

In the workflow of digital photography, the original data file format is becoming more and more popular, and it is becoming a hot fashion because it provides more creative control space for image production professionals. However, cameras can use various raw data formats, and the specifications of these formats are not public, which means that not every raw data file can be read by many software applications. Therefore, adopting these proprietary raw data files as a long-term archiving solution has certain risks, and it is more challenging to enjoy these files in multiple complex workflows.

What is the solution to this increasingly concerned problem? Digital negative (DNG) is a common archive format for the original data files of digital cameras. DNG solves the problem of lack of open standards between the original data files of different cameras, thus helping to ensure that photographers can access their files in the future.

Within two years after the introduction of DNG format, dozens of software manufacturers have developed support for DNG, such as Extensis, Canto, iView and Apple. Many famous camera manufacturers, such as Hasselblad, Leica, Ricoh and Samsung, have introduced cameras that directly support DNG.

For photographers, the main advantages of DNG are:

DNG format helps to enhance the confidence of archiving, because digital image processing software solutions can open original data files more easily in the future.

When processing camera raw data files from multiple manufacturers or models, a single raw data processing solution can improve the efficiency of workflow.

An open and ready-to-use archive specification is easier to be adopted by camera manufacturers, and it is also easier to update to adapt to the development of future technology.

For hardware and software manufacturers, the main advantages of DNG are:

DNG has eliminated the potential obstacles for new cameras to adopt this format, because the original data files of new cameras will soon be supported by Photoshop and other applications.

DNG format makes it unnecessary for merchants to develop new formats, and can simplify the camera testing process, thus greatly saving research and development costs.

As a general format, DNG enables third-party applications to strengthen the control over the quality of conversion.

This specification allows special metadata to be added to DNG files to distinguish them.

The problem of RAW format

The RAW format can only be adjusted by the user himself, not by the camera automatically. In this case, the usability after taking pictures becomes a big problem. Although all digital SLR cameras can output files in RAW format, there is no standard format, and the data items and specific storage methods are decided by the manufacturers themselves. Even the products of the same manufacturer have the problem that the content of RAW format is not uniform.

Therefore, there are only two ways for users to browse RAW format pictures and then adjust the picture quality. One way is to use special software provided by digital camera manufacturers. However, the ease of use of dedicated software may not be in line with users' preferences. Another method is that users first convert the data format, and then browse the pictures with their favorite picture editing software to adjust the picture quality. For example, Adobe introduced free software to explain the RAW format of many cameras in the form of "Photoshop" plug-in software.

This method of using RAW format pictures introduced by Adobe has some problems in long-term preservation. "If you save the original image before editing in RAW format, after 20 or 30 years, even if you suddenly want to open the image file, you may not find the software needed to open the image file."

Adobe believes that this kind of thing can be avoided if DNG format is popularized as an industry standard file format. The company's policy is that "files in DNG format can be used permanently through Photoshop". DNG format can save various metadata, such as camera settings. Therefore, even if it is converted to DNG format, the metadata in RAW format will not be lost. In addition, the image data in DNG format is based on TIFF format.

Adobe said: "Because DNG has many advantages such as free use, we believe this format will be popularized in the future."

How to change the use?

In addition to the digital negative specification, Adobe also provides a free Adobe DNG converter, which can easily convert raw data files from many popular cameras today. The latest DNG converter 3.6 can provide universal binary files for Intel-based Macintosh computers.

Adobe(R) Photoshop(R) CS2, Photoshop CS, Photoshop Elements 3.0, Photoshop Elements 4.0 and Photoshop Elements 5.0 all support DNG.

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Will DNG become the mainstream of digital photos in the future?

Using the new image format, Adobe thinks it can improve the quality and life of digital photos, but it faces severe challenges.

Adobe is vigorously promoting its "Digital Negative" (DNG) picture format, hoping to replace various formats currently used in high-end digital cameras. Adobe believes that a unified format will benefit industries and users.

At present, the challenge faced by Adobe is to create user needs and seek industrial alliances. So far, only a few digital cameras support digital negative format, which has not eliminated the situation of various picture formats in digital cameras, and digital negative format is not a neutral industry standard.

But Adobe is patient. Tom Hogarty, manager of Adobe's digital imaging products division, said: "When we announced the DNG format two years ago, we said it would be a long acceptance process.

We already have some digital cameras that support this format. This is a good progress. "

Digital negative format is a public archive format, which is used for the "raw data file" of digital cameras. Most digital cameras convert the data of their photoreceptors into JPEG format, and the so-called original data files record unprocessed picture data. Photographers must use software to convert this raw data file into a more convenient picture format, such as JPEG or TIFF format.

All single-lens reflex digital cameras (SLR) and some low-end cameras can save image data as their own "original data file" format. In order to get more detailed exposure processing and picture effect, many photographers have accepted the raw format.

Ray Barlow, a natural scenery photographer in Ontario, said: "95% of the photos I take are landscape photos, and the raw format allows me to take good photos before I actually edit them."

However, the raw format has brought problems to companies such as Adobe, and they must write processing software for the raw image format of each new digital camera.

Dave Story, vice president of Adobe's digital imaging products division, said: "The diversity of original image formats is too complicated." As more and more digital cameras increase raw support, this problem will become more and more serious.

The second main motivation for launching the digital negative format is to make the raw format have a unified filing standard, so that users can open their own photos even if a digital camera manufacturer no longer launches software to handle its raw format in the future, or a camera manufacturer launches the camera market.

Hogati said: "Now every digital camera has its own raw format. Will it be easy to find software supporting these formats in five years, 10, or 15?

Is it necessary for each vendor to launch its own format? Wouldn't it be better to have a universal solution? "

This idea attracted some photographers. Holly Yurchison, a photographer in Cincinnati, said: "It's a good idea to establish a unified standard for raw, because we don't know the future fate of these photos."

Ken Milburn, the author of Digital Camera Technology, likes the long-term effects of digital negatives. Milburn said: "It makes sense to convert any picture format in your camera into digital negative format." (Adobe currently provides a tool for converting photos into digital negative format for free. )

The popularity of DNG is not fast. Unifying the raw format is not a simple matter. Doug Meisner, senior manager of Paint Shop Pro Photo product department of Corel Company, made a * * * sound for Adobe's DNG project. But he expressed concern about the future of digital negatives.

Meissner said: "When we first heard the DNG format, we thought it was great. However, we later found that with DNG, our software still has to do a lot of processing tasks, just like without DNG. For example, our software still needs to know which camera took the picture first, so DNG is not good for us. "

Hogarty admits that DNG does not contain some information about a painting. He said: "DNG provides all the necessary data to accurately describe the information of a photo, but the algorithms in raw format used by various manufacturers in the imaging industry are very different."

Apple, which sells original processing software, also found that DNG is not perfect.

In addition, Apple believes that DNG is not a neutral industry standard because it is still controlled by Adobe.

Kirk Paulsen, senior director of Apple's professional application products division, said: "Our idea is that if DNG can be managed by a standards organization, then this format can be widely accepted by the public like JPEG format. The current situation is that we can only look at the colors of camera manufacturers or software companies. I think users still want to place their hopes on standards organizations. "

Adobe's ownership of DNG is also a problem for camera manufacturer Olympus. John Knaur, product manager of Olympus SLR camera division, said: "At present, we have not seen this format become a cross-platform de facto standard. It is just a picture format controlled by Adobe."

Although Adobe owns DNG, it discloses all the technical details of this format, and it also provides patent information to supporters of DNG for free.

Adobe also said that it plans to give up control of DNG. Hogati said: "It may be more efficient for one or two companies to form an alliance and then hand over the results of DNG to a standards organization for management."

It is not widely accepted for camera manufacturers to join DNG, but Adobe already has some alliances. They are:

Leica's M8 camera adopts DNG format.

Ricoh does not provide raw format support in most of its cameras, but in its GR cameras, Ricoh has added DNG format support.

Hasselblad, which specializes in producing high-end cameras, added DNG support to its 39-megapixel H3D camera, but this year, the company cancelled this support when upgrading this camera.

Victor Naranjo, regional manager of Hasselblad, said that DNG does not support some high-end picture functions, such as automatic compensation for chromatic aberration caused by lens. In addition, it does not support distortion correction and photo blur correction. He said: "We can't shoot directly with DNG. In the future, this format may become a reality. "

Apart from these companies, Adobe can hardly find partners.

Nikon, a big manufacturer of SLR digital cameras, said it has no plans to support DNG format.

Both Olympus and Canon are studying DNG, but they have not indicated when they will support this format. Panasonic, which has entered the SLR digital camera industry, said: "At present, we have no plans to support DNG format, but we will pay close attention to the development of this technology trend."

Espen Hildrup, a photographer from Oslo, Norway, said that he didn't want camera manufacturers to unify the format, because he didn't want to lose some manufacturers' unique image format functions, such as the warm color function of Olympus or the dimming function of Nikon.

There are more and more original formats. Adobe's story holds that the Raw format will continue to increase, so users can take better photos with their cameras.

Story said: "For consumer cameras, megapixels are not the ultimate goal. The mega pixel war is coming to an end. You can now spend $400 on a10 megapixel digital camera. "

Chuck Westfall, head of Canon's media and customer relations department, believes that the quality of Raw photos of compact digital cameras is not necessarily better than that of JPEG format. Based on this consideration, in September this year, Canon cancelled its support for DNG when it launched the10 megapixel G7 camera. The original 765,438+megapixel PowerShot G6 supported the Raw format.

There are more and more pixels in a digital camera, which means that the photoreceptor in the camera is getting smaller and smaller. The smaller the sensor becomes, the more difficult it is to distinguish the difference between the incident optical signal and the electrical signal generated by the components in the sensor. In this case, adding raw support will not help to improve the image quality.

Photographers said that Adobe must have got the support of some photographers.

Eric Lawton, an amateur photographer, said, "DNG can be a bridge between my Nikon camera and my Canon camera."

However, sports photographer Bill Frakes has reservations. His favorite photo archiving formats are raw, JPEG and TIFF, not DNG. Although he agrees with Adobe's proposal to unify the raw format, he is not optimistic about whether DNG format can become the mainstream format.

Frakes said: "I hope there will be a standard here, but I don't think this wish will come true."