Browsers & Color Management I – Sending Color Patches through the Web Browser

While writing my previous posts on color management and web browsers [1, 2], I realized that instead of guessing as to whether a browser understands how to manage colors, a few measurements of color patches would go a long way. Questions, such as, what will happen with untagged images in Chrome 11 or is it safe to use sRGB profile for photos displayed on a wide-gamut monitor would then be easier to answer. By all means, these questions are not trivial and would deserve an in-depth study of the browser documentation and perhaps many hours spent on Google. Unfortunately, with many browsers one would still be unclear on the exact way by which are the (un)tagged images processed.

To address browser color capabilities in the most straightforward way, we would just send images of RGB primaries through the browser and record their colorimetric values. In order to do that, we would need a set of images that are either untagged (no color space information is associated with them) or images that carry color space information in the form of icc/icm profile. After the measurement is done, a quick comparison with known CIE 1931 chromaticity coordinates of RGB primaries of standard color spaces (sRGB, Adobe98 RGB, Pro Photo RGB) would reveal any color processing done by the browser. To measure the radiometric output, we can use the same device that we use to calibrate our display.

To make measurement of colors from within a browser easier, I provide jQuery script that displays different color patches and allows measurement in a semi-manual manner. The script runs in any browser that has JavaScript enabled. Included are gray and RGB ramps in four different variants; untagged and tagged with sRGB, Adobe98 RGB, and ProPhoto RGB icc profiles. After measuring these patches directly from the browser, we can both judge its color management capabilities and also obtain display characteristics, such as, display gamma, color temperature and gamma values for each RGB channel. On that later (link).

The Upshot of the Script:

  • Inter-browser compatibility (IE, Chrome, Firefox, Safari, Opera, …)
  • No installation (all necessary files are included)
  • No need to be connected to the Internet
  • Simple navigation (NEXT, PREVIOUS, RESET)
  • Customizable (supply your own images)
  • Free

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mpatek November 27, 2011 Filed in: → Code, Color management, Software No Responses

Enabling color management in Google Chrome

In my previous post, I provided a step-by-step guide to enable full color management in the Mozilla Firefox browser. While Firefox handles colors in a very respectful way, there are other browsers that cannot be setup (yet) to effectively manage colors (IE, Opera). For some time, Google Chrome was not capable of managing colors also or its setup was just undocumented. However, while there are several pages on the Internet describing how to enable color management in Chrome, results are often unreliable (read more below).

In general, the first part of troubleshooting annoying color shifts is checking that our monitor is calibrated and profiled.

This post will show modification in a simple start-up option that enables management of colors in the Chrome browser (I am intentionally avoiding the term “color management” for the reasons explained below).

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mpatek November 19, 2011 Filed in: → Software 4 Responses

Full color management in Firefox – settings

Every day, hundreds of thousands of photos are uploaded to the web. There are many web surfers, photography amateurs, pros and photo agencies browsing for the best pictures. Nothings gets more frustrating then seeing an image that took several hours of editing and rigorous color management discipline, only to realize that colors got shifted and that the whole visual experience is compromised. Main culprit is often wrong setup of the web browser or use of browser that cannot be setup to effectively manage colors (IE, Opera).

In general, the first part of troubleshooting color shifts is checking that our monitor is calibrated and profiled.

This post will guide you through the powerful options in Firefox that enable color management of images that are tagged with icc profile. If the image is not tagged with icc profile, its color interpretation will default to the computer system color space, which in most cases is close to sRGBinfo and and then converted to the monitor RGB. If the image is tagged with icc profile and if there is no monitor profile available, monitor RGB values are assumed and the monitor default profile is used for conversion. For calibrated and profiled or any decent monitor, results for tagged and untagged (but edited on standard sRGB gamut monitor) images will be just fine. However, troubles will most probably arise on a wide-gamut monitor.

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mpatek November 2, 2011 Filed in: → Code No Responses