Viewing Photographs on the Web

Photographs on the web are usually intended to be viewed using a calibrated and profiled monitor and a color-managed browser, with the ambient light levels being about as bright as the brightness of the monitor itself. In the small pool of color-managed browers, Firefox is still the best, though sadly Firefox color management is not as good as it used to be.

This page has information about Firefox color management and links to resources for monitor evaluation and for calibrating and profiling your monitor.

Written in 2012. Updated in 2015.

Firefox — the best of a bad lot

Even in 2015, browser color management remains an iffy proposition, with Firefox being the best of a bad lot. Simon Tindemans' Web browser color management provides a nice overview of browser color management support, along with notes on the color management settings in each browser. His article is not specifically oriented towards Linux and I'm pretty sure there are OS-specific differences even for the cross-OS browsers like Chrome and Firefox. I don't use any browser besides Firefox, and I don't use any OS besides Linux, so I can't fill in the gaps. But here's a screenshot of my Firefox version 31 color management settings:

The above screenshot shows proper Firefox color management settings. After typing in "about:config" and making the changes, you have to restart Firefox before the changes take effect. Of course for the first line you should type in the path to and file name of your own display (monitor) profile. Or if you leave this field blank, presumably Firefox will pick up the installed system profile. But this only works if you've actually installed a system monitor profile.

The Firefox color management settings shown in Figure 1 above are the right settings for most people. I can't think of a scenario where you'd want to use the default Firefox settings. On Linux your display profile is located wherever you — or whatever "desktop" color management program you might be using — decided to put it. I don't use "desktop" color management programs (my "desktop" is the ultra-lightweight IceWM, at least until X is retired). So I can't tell you where such programs might put your monitor profile (but check "$HOME/.config/color/icc/devices/display/").

Firefox then and now, or the difference black point compensation makes

Back in 2009, photographers everywhere rejoiced because Firefox 3 was fully color managed using LittleCMS. Then a minor LCMS security alert was issued, and even though it was immediately patched, Firefox dropped LCMS like a hot potato and rolled their own color management code. Although Firefox 3 supported black point compensation and the use of certain lookup table (LUT) profiles, Firefox 4 did not. See these two Argyllcms posts for commentary by color management experts Chris Lilley and Graeme Gill: Color management in Firefox and XYZ LUT profile unable to be installed on WindowsXP or used with Firefox 3.5. Update: In 2017, it seems Firefox can use XYZ LUT profiles, but not LAB LUT profiles.

As of 2015 and version 31, Firefox still doesn't support black point compensation, which means that if . . .

you have properly calibrated and profiled your monitor, and your monitor has a reasonable black black point
you have your color managed image editor set to use relative colorimetric intent with black point compensation for display to the monitor
you produce a finished image ready for display on the web
you view the finished image in Firefox

. . . then as displayed by Firefox the shadows in your image will be more or less crushed compared to how the same image is displayed in your color managed image editor.

Black point compensation "compensates" for the fact that monitors can't display "no light". Without black point compensation, all shadows darker than the darkest dark your monitor can actually display are simply crushed to solid black. In a high key image image or an image that has few important shadows, you might not notice any difference. In an image that's supposed to have rich dark shadows, the difference can ruin your appreciation of the image as all the shadow detail turns to muck.

Monitor evaluation

Of course if your monitor isn't properly calibrated and profiled, or if you naively think sRGB makes a good monitor profile for your spiffy LCD monitor, or if you don't use a properly color-managed browser, then when you view images on the internet, the photographs as displayed by your broswer aren't going to look the same as the images the photographer intended to display.

"What you see sometimes isn't what was intended" cuts both ways: Putting aside the issue of black point compensation, not everyone who uploads images to the web is using a decent quality, properly calibrated and profiled monitor in a fully color-managed workflow. So it's entirely possible that the images any given photographer uploads to the web don't look "as intended" on any monitor other than the photographer's own monitor.

Here are three websites for checking to see how well your monitor performs:

Dry Creek Photo's Monitor Black Point Check does exactly what it says. Also click through to the Monitor Luminance Sensitivity and Monitor Grayscale Test Image.
The Lagom LCD monitor test pages provides a full test suite for checking your monitor's performance.
Test Cards for Monitor Adjustment provides a practical set of two test images for checking your monitor calibration, which is a good thing to do even if you've already profiled and calibrated your monitor with a color measuring device. If you don't have a color measuring device, the test cards can also be used for making adjustments to your monitor calibration.