Skip navigation

Working with Raw Image Files

Today, all digital cameras support a popular image format called JPEG, which offers so-called lossy compression, in which data is actually deleted to make file sizes smaller. Most cameras offer a few quality settings, and my advice is to always use the highest-quality setting that your digital camera offers so that you get the best possible images.

But JPEG images have problems. The most egregious is that every time you edit a JPEG image and resave the file, it's recompressed, so you lose data again. It's possible to literally degrade the quality of JPEG images over time—a scary proposition. One way to avoid this problem is to make backups of the original photos each time you copy them to your PC. But for an emerging generation of digital-photography power users, there's an even better solution: It's called Raw image format.

Raw Power
Today, many high-end cameras support some sort of Raw image format, and we're starting to see the feature move down toward the middle segment of the market, as well. Sometimes referred to as a "digital negative," Raw images represent the exact image that your camera captured, in full uncompressed glory.

However, you don't have to be a mathematician to understand the most obvious problem with Raw images: size. Raw images are many times larger than even the highest-quality JPEG images because none of the information in the file has been removed (or compressed). But even if file size doesn't scare you off—and it shouldn't, given the processing power and hard-disk capacities of today's PCs—Raw images present a few other problems.

First, there's no such thing as a standard Raw image format. Each camera maker has its own Raw image format, and many vendors institute new versions with each new model release. Second, no OS natively supports Raw images, so you typically need to buy or download special tools to work with them. That latter point is important because you're going to want to edit most Raw images—for example, adjust the white balance or color—and then save an edited version in JPEG, PNG, or TIFF format for archival purposes. You never make changes to the original Raw image. Remember, it's like a digital negative.

So what's an aspiring photographer to do? First, know your options. Here are some solutions for dealing with Raw images today.

Adobe PhotoShop and PhotoShop Elements
Most professional digital photographers use Adobe's powerful and expensive PhotoShop application to manage and edit Raw images. That's a fine option, but the budget-oriented PhotoShop Elements 3.0 ($99 or less at retail) works just as well and won't require a second mortgage. The problem with PhotoShop/PhotoShop Elements' support of Raw images is that Adobe is basically reverse-engineering each Raw image format as it comes out. Therefore, you'll be able to download filters for new cameras from Adobe's Web site, but those filters will often trail the release of the cameras by several months, thereby stranding early adopters.

When you import a supported Raw image into PhotoShop, you can make numerous changes to such image features as white balance, temperature, exposure, and brightness. After you preview your changes, PhotoShop imports the file. However, you can't resave the original. Instead, you can output the image as a more common file type, such as JPEG, then print it or share it as usual.

It's worth noting that Adobe has offered a file format called Adobe Digital NeGative (DNG) as a standard, of sorts, for Raw image files. To date, few camera makers have shown any interest in this format, however. Modern PhotoShop/PhotoShop Elements versions support it.

Apple Mac OS X 10.4 "Tiger"
With the release of Mac OS X 10.4 "Tiger," Apple has added basic support for Raw images to its OS and to the iPhoto digital photo management application. Sadly, Apple, like Adobe, has decided to go its own route with Raw image support: The company is manually reverse-engineering each Raw image format so that photos in those formats will work properly in iPhoto. Therefore, iPhoto will also lag behind as new Raw image formats appear in new cameras.

Raw image support in iPhoto has other problems. In its bid to keep things simple, Apple maintains two copies of each Raw image you import into iPhoto. One copy is the original Raw image. The other is a lower-quality JPEG image that the application displays to avoid a performance lag. However, when you edit a Raw image in iPhoto, you're actually just editing the JPEG version—not the original. Thus, each edit you make will likely impact the overall quality of the finished product.

In short, Apple's support of Raw images is half-baked at best, but it's better than nothing. I advise photographers who use the Macintosh to skip iPhoto and instead use third-party tools such as Adobe PhotoShop or PhotoShop Elements to manage and edit Raw images.

Raw Image Viewer PowerToy for Windows XP
Microsoft's support of Raw images takes a different tact than that of Adobe and Apple. Instead of reverse-engineering the Raw image formats, Microsoft contacted all the camera companies and offered to create an industry-standard way to handle Raw images. Under this scheme, each camera maker is free to extend the format as it sees fit, but it will publish information about the changes so that others can access the new formats in a more timely manner. So far, two of the four major camera vendors that make products using Raw formats—Canon and Nikon—have agreed to this scheme, and even Adobe is on board, offering up its DNG format as well. Microsoft is in talks with the other camera makers.

The first product to take advantage of this work is a recently released and free PowerToy for Windows XP that lets XP users natively work with various Raw image formats directly from the Windows shell. Therefore, you can view and organize these types of images directly from within Windows, in much the same way that you can manipulate JPEG and GIF images. You can also use the PowerToy to print, but not edit, supported Raw image files. You'll still need an external editor to edit such images.

The PowerToy comes with other less obvious caveats. First, the performance is somewhat miserable, especially if you work with a lot of image files in one folder. Thumbnail generation is slow, and launching the image viewer is likewise poky. However, users of Raw image files understand that these images are humongous, so the performance concerns shouldn't be surprising.

Second, because Microsoft has partnered with only a limited number of camera makers, the PowerToy doesn't support all digital-camera Raw image formats. For example, it doesn't work with images that Fuji or Sony cameras generate, although such support could certainly appear in a future update. You can find the XP Raw Image Viewer PowerToy on the Microsoft Web site.

Microsoft Digital Image Suite 2006
This week, Microsoft shipped a new version of Digital Image Suite, its low-cost and easy-to-use image-editing-and-management suite of applications. Digital Image Suite 2006 includes many new features, but one of them—Raw image support—will be of interest to high-end digital camera users. Digital Image Suite 2006 supports Raw images in two ways. The Microsoft Digital Image Suite 2006 Library natively organizes Raw images and displays accurate thumbnails. And the Microsoft Digital Image Suite 2006 Editor can actually edit Raw images, making it the first inexpensive and mainstream application outside of PhotoShop Elements to do so.

Here's how it works. You drag Raw images into Digital Image Suite 2006 Editor as you would any other image file. Unlike PhotoShop, this software displays the image natively in the editor and doesn't prompt you with an Import dialog box. You can make changes to the file as usual. For example, you can apply the various Auto Fix filters (e.g., Color Auto Fix, Exposure Auto Fix), or use the more complex Touchup tools to perform operations in a task-based way. As with PhotoShop, you can't resave the edited image in its original Raw image format. So, when you select File and Save, you get a dialog box in which to choose the format to use (the default is JPEG).

Looking Ahead to Longhorn
In the next major Windows version, code-named Longhorn, Microsoft will support Raw image viewing, management, and editing directly in the Windows shell. Because that OS is still over a year away, I won't get into too much detail here. But I'll be publishing a lengthy article about Raw image support in Longhorn for the SuperSite for Windows within the week. Check back soon.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.