By Marc Aguilera

Almost everyone I know who is in professional digital photography has heard of sRGB. In many ways it’s difficult to escape because it’s the default color space in many cameras, photo printers, and in Adobe Photoshop. Did you know there was a replacement for sRGB? And did you know the common profile you think of as sRGB is actually a v2 profile?

The ICC (International Color Consortium) has replaced sRGB v2 with sRGB v4. However, sRGB v4 is meant to be used in conjunction with other v4 profiles.

Advantages of sRGB v4: The advantages of sRGB v4 are most pleasing when you transform color from sRGB v4 as a working space to a correctly constructed v4 output profile using the perceptual rendering intent. There is also higher color accuracy using the relative colorimetric intent. Even though many professional photographers use Adobe RGB or ProPhoto RGB, with an sRGB v4 workflow photographers may actually see in print a better rendition of their original files. Details in shadows and colors that previously were compressed or clipped due to the rendering intent will now appear to render with more fidelity to the original. This is essentially the reason for sRGB v4.

The first thing to do is to assign the new sRGB v4 profile to your digital images. You can download the sRGB v4 profile here.

Remember that profiles need to be installed into the proper directory in order for Adobe Photoshop to recognize them. The directories are 

• 
  
   Windows/System32/Spool/Drivers/Color
  
  


• 
  
  Library/Colorsync/Profiles for Mac OS 10.x
  
  

When you assign a profile, you change its relationship to color appearance by changing the way the RGB values relate to L*a*b*. You may or may not see a change when you assign the sRGB v4 profile. The advantages to sRGB v4 really are when you go to print using a v4 output profile.

 Building v4 Output Profiles: If you can build your own ICC output profiles then you have all the power you need. By default, the preferences in X-Rite’s i1 Match software (which I use) build profiles according to the ICC v2 specification. With a change of preferences you can build v4 profiles. Open the preferences to change the options (See Fig. 1 below).

If you rely on manufacturers’ “canned” profiles you will have to ask the individual manufacturer if the downloaded profile is v2 or v4. Most likely they are all v2 but that will slowly change. Most photo labs don’t have output profiles, but if they do, ask if they use v2 or v4 profiles. If they use v4 profiles then you will be able to take advantage of sRGB V4.

This is why I love having my own color management system and printer. I can build my own profiles for my printer and not have to wait for a paper manufacturer to build one for me or have a photo lab send me one.

Most competitive software from X-Rite, Datacolor, or Fuji will build v4 profiles. However it’s best to check with your reseller regarding the support.

Click here to get a list of applications that support the ICC v4 spec.

V4 profiles don’t take any longer to build and the test charts are still the same.  The differences are mostly in how the rendering intents maps colors from source to destination color.

In the Color Management for Photographers and Color Management for Creatives courses that I teach at UCSD Extension and the Digital Arts Center we have been experimenting with v4 profiles. And I must say there is a slight difference between v2 and v4 that makes the print slightly more pleasing. The biggest difference seems to be in screen-to-print matching.

ICC Color.org: Navigate to the ICC site and you can read vast numbers of white papers regarding everything ICC. There are profiles available for download as well as presentations and tools for members. You can also read more about the new sRGB v4 specification and how it compares to v2.

Even if you are new to ICC, this site is a must for reference and when you want the most details regarding the world of profiles.

By Marc Aguilera

Understanding color management in web browsers is important if you want to directly sell more of your photos and artwork online. You need to know what is and isn't currently possible when it comes to ensuring that your images will consistently look as you intended when you display them in your online gallery.

First of all, know this: All devices produce color differently (we color freaks call it `device dependent color'). Even two of the same devices from the same manufacturer sitting next to each other will look slightly different. This can be hell—especially if you're trying to manage the color of your photographs on the web.

Second, applications can treat color differently. Have you ever wondered why images look a certain way in Photoshop and another way in your email program or the web? It's the same file and on the same computer but it looks different in various applications.

Mac OS X applications built using Aqua (i.e Mail, Preview, Safari, and iPhoto) all use the default display profile and recognize embedded profiles. This means images look the same in the applications

Microsoft applications such Picture Viewer and Outlook don't recognize embedded profiles, so when comparing images in Photoshop and Picture Viewer you will see a difference.

Adobe applications all have a common color architecture and if you synchronize working spaces the color will all look the same—but only in Adobe applications.

Internet Explorer 7 has can recognize embedded profiles in images, but the user has to enable it in preferences.

The current release of Firefox doesn't include support for embedded profiles in images but will do so in future versions.

So no matter what, if you plan to implement a color-managed workflow, your images will look similar in ICC-aware applications but different in everything else.

Secondly, if your display is not calibrated and profiled you will have even more trouble. Color measuring your display is crucial if you want a consistent appearance. (If you don't calibrate your display, you'll simply be experimenting with color rather than managing it.)

Here's how we manage color in at our creative-services agency, encompus:

• All of the displays in our studio (5 Macs and 2 Windows) are all calibrated with a spectrophotometer to the same settings - D65 (6500° Kelvin), Gamma 2.2, and 130 cd/m2 Luminance. When we share files and view the displays under similar lighting conditions, these displays all appear similar. Then, the question then becomes one of application implementation.


• We run Mac OS 10.4 for design work and Windows XP for web production work.


• We all share the same color settings file (.CSF) in our Adobe Applications. sRGB is the working space for our web work and Adobe RGB is working space for our print work.


• When a designer prepares an image for the web, we "save for web" via Adobe ImageReady. We embed the ICC profile when we really need to match colors and don't embed the profile when it's not as crucial.


• We brief our clients on real-world expectations based on the fact that their customers will be viewing our design work on different browsers and on uncalibrated displays.


• When we embed sRGB, it is really only useful for Safari since Safari has color management enabled by default and can recognize an image with an embedded profile. It does not help us with Firefox, unless you're running Firefox 3 Alpha 7 which has an option to use embedded profiles.

The concepts of the ICC (International Color Consortium) are still relatively young. ICC standards were written to be open in terms of implementation, meaning that OS, Applications, and Devices could use ICC profiles differently or not at all.

This concept makes it a nightmare for everyone because although the profile is a standard file type, the uses of a profile all differ depending on application and operating system. At least Apple has taken a huge step forward with Colorsync and Aqua, and Windows Vista has a new color management system called WCS (Windows Color System).

Still, I would prefer that all photographers, designers, and prepress professionals all follow the imperfect ICC color standards than try to invent new ones at this stage.

It really comes down to setting expectations within your devices and with the client. If you're considering selling photos or prints online, you may want to adopt a policy similar to that of the online
art gallery that gives customers seven days to return any artwork they bought that doesn't look like they had expected it to.

Let’s recap :

1. Calibrate your display to a standard (i.e. D65, G 2.2, Luminance 120 cd/m2). Recalibrate at least once a quarter.


2. Use sRGB as a working space for your web images. Make sure all your applications do the same (although this can be challenge for some applications).


3. When you save your images for the web, embed sRGB profiles. For now, they may not look right in Internet Explorer 7 and Firefox, but there will come a time (sooner, rather than later) when all the major browsers will have color management turned on as the default, like Safari.

If you want to learn more about this subject, read Real World Color Management published by Peachpit Press. Better yet, take the X-Rite-sponsored Color Control Freak 08 seminar that I will be teaching at 24 cities throughout the US this spring. We will discuss many of these issues and more. Check out X-rite’s website or contact me directly at encompus.