Color Profiles

I recently encountered a question about color profiling and the answer required more then the 140 characters allocated for the question. There is plenty of more professional information about this out there – but I am guessing that a lot of people can make do with a simple explanation.

Why should you care about color profiles?

Ironically because what you see is not what you get. I will use still photography as an example – but this implies just as well for any digital imaging technology.

• When you capture an image with a digital camera there are numerous processes taking place that convert the image you think you see (the eyes & mind can be very deceiving – sometimes more then technology). One of these processes is a conversion of light into digital data and then a conversion of that data to a digital file (for most people this will be a JPG file, for some professionals this can be what is called a RAW file format – which handles information in a different way). The conversion into a digital file usually includes a color profile which says something about how the information was stored in the file and how that information should be interpreted.
• When you view that image file on a computer screen – that file is interpreted by at least one software application – usually two. One is the operating system (Windows, OSX, Linux…) – and the other is the application you are using to view (and modify) the image. Photoshop, for example, can (and often does) affect the way an image is presented because it a professional tool and professional need this kind of control (yes – this means that you may see the same image file differently when viewed through photoshop and through the native windows picture viewer).
• When you print that image file (at home or at a print service) it is intepreted by drivers and software applications that are converting the digital data into commands to the printer which usually take into acount (amongst other things) the kind of paper and the kind of inks used in the printer (yes – this means that with different inks and different papers you will get different colors printed).

So the beautiful colors you saw in the flowers will look differnet on the screen of your camera, on your computer screen and in print. For professionals this can be a very challenging process and opens a door to wide topic of color management and color profiling.

What is a Color Profile?

To understand color profiles something needs to be said about color spaces. A color space is a fixed and precise mathematical definition of how digital color information is interpreted into colors. It is an arbitrary system – two popular color spaces are sRGB and AdobeRGB (there are additional color spaces).

sRGB is a basic space that can be thought of as the “lowest common denominator” in color management. It is the default color space used in computers. Computer screens are capable of producing sRGB colors and therefor most software applications use sRGB as their default color space. But, if you intend to make professional prints of your images and you want finer control and precision in color (so that the printed red color of the flower is similar to the actual red you think you saw when you took the image) – then you will probably use a different color space. AdobeRGB is a color space with a wider gamut – meaning it can display more colors then sRGB. If you are just viewing images on an average computer screen then you will not see a difference between the two – because the screen’s technology is not able to show you the difference.

Here is where color profiles become useful. If you walk into any computer store that has a display of computer screens – all showing the same image – you will notice that the image appears different on different displays. Color profiles are used to fine tune the way information is displayed (and printed) in a way that creates consistency. Without them your flickr image that looks great on your computer may look drained of color when you share it with your friend.

How are Color Profiles used

Color Profiles are files. They usually have an extension of ‘.icc’. Color Profile files come with your operating system. Color Profiles files somtimes come with your screen and they indicate how digital visual information should be converted to appear on the specific screen (if all the screens in the computer store were properly profiles – they would be theoretically displaying an objectively similar image). Color Profile files sometimes come with your printers – and they are used by your printer drivers to convert the same digital visual information into print commands that take into consideration the color behavior of the printer.

There are hardware and software tools to create custom profiles. I use a device that attaches to my screen and measures the color output with a dedicated software profiling application. It then guides me how to modify the color settings of my screen so that the color representation is more precise (similar to what I saw and similar to what I will get in a print). The result is an ‘.icc’ file that is tailored for my screen. If I really want to stay on top of things I need to do this regularly – because the color behavior of my screen changes over time. I also need to do this on my laptop screen so that the images look pretty much the same on both computers.

Color Profiles and Firefox 3

Finally – to answer the question. Firefox 3 has introduced color profiling. There is also a plugin to control the settings for color profiles. I found a post on Deb Richardson’s blog that has some information on this and also some images which exemplify how looks can be deceiving.

The question is what to choose as your color profile? If you haven’t messed around with any other color settings in your workflow (operating system and applications) then you are probably running sRGB. If this is the case then you need not choose anything. If you are using another color profile (and if you are using professional programs such as Lightroom you may be unconsciously using other profiles) – then you need to find that color profile file and have the plugin use that file.

TIP: Windows XP profiles can be found in Windows/system32/spool/drivers/color

It has occurred to me that if you are not using professional or color managed graphic applications then your images will actually look better in Firefox3 with color management enabled. Like I said looks can be deceiving.

A sidenote on viewing images on the web. Images optimized for the web are often compacted to create small files. This means that some information (visual quality) has been lost for the benefit of faster downloads. There is a huge difference between my source files viewed by a professional editing program and the images that are displayed on the web – they are always less vibrant & less detailed.

In the end

Color management is a complicated and pain in the neck process. Unless you really need it, I suggest you stay away. If you really need make sure you have the time, patience and a budget to invest in it – you will need them all. My personal feeling is that the goodness of images transcends most technological challenges (and then some).