The World Wide Web and Color Management: Assigned, not Converted

Recently I had access to an Eizo ColorEdge CG 277, which is Eizo’s flagship monitor for highest standards of color accuracy and consistency. The monitor features a built-in calibration sensor and covers 99% of the Adobe RGB color space.

Although the monitor is able to achieve a 10 bit color depth (per channel), the entire chain was not, as I figured out using a test rampBut even though, the tiff images that I brought on a USB stick and opened in Photoshop CS6 simply popped out of the screen. This is the second-best thing next to a fine art print. It is clear that I must free some space in my home office.


Image developed in Capture One Pro, saved as 16-bit tiff, down-sampled into 8-bit jpeg, and converted into the sRGB color space before upload.

But then I opened my web page in the Safari browser and was shocked. The images looked like kitsch*. On the contrary, the Safari browser on the MAC renders some of the images rather dull when compared to the tiffs opened in Photoshop. I had attributed this to the down sampling and heavy jpeg compression, but should have known better: most web-hosting services and web browsers do not support color management.

* Although I keep seeing such examples in magazines, a lake in Scotland photographed under a gray sky cannot look like the waters of Anse La Digue. And if it does in print, it’s kitsch.

The hue shifts result from incorrect assignments of ICC profiles** or incorrect conversions of the working color spaces, in particular on 8-bit jpegs. If an image has been converted to sRGB, for example, but the receiving application assigns (not converts to) the larger Adobe RGB color space, the image will look blown out, as stronger colors from the larger gamut are applied. It is like using very concentrated balsamic vinegar in place of the normal grade and fail to adjust the recipe.

** An ICC profile is the color “identity card” of a device or an image, containing the information on the color space of the device together with its characteristics in known calibration conditions.

As long as you view, in Photoshop, an image that has an embedded ICC color profile, the monitor profile in the operation system compensates for whatever working color space is used. However, the Safari browser does not read embedded profiles. All non-ICC-aware applications simply defer to the operation system to interpret the image and assign the monitor profile. The assumption is always that the image is in the system profile, e.g., the one of the monitor. In my case, the larger Adobe RGB color space was enabled on the Eizo screen.

The action that created kitsch in the first place, goes into the reverse direction when the images are uploaded on the WordPress site. sRGB is the unofficial, default color space of the web. As the web-hosting service does not color manage, the uploaded images are simply interpreted as sRGB although they are saved in the larger Adobe RGB space: So the working color space is assigned, not converted.


Identical image to the one above. But this time uploaded with the embedded Adobe RGB profile.

I must now go through my entire web uploads and manually convert the images into the sRGB color space, a boring job indeed. It would be much better if the web hosts and browsers supported color management.

Knowledge is for sharing:Share on Google+Share on LinkedInTweet about this on TwitterShare on FacebookEmail this to someonePrint this page
This entry was posted in Image quality and tagged .

Post a Comment

Your email is never published nor shared. Required fields are marked *


Follow Me