On Apr 15, 2005, at 3:20 PM, Rob Studdert wrote:
OK, so on your system I assume that files rendered as sRGB with and without
profile look very similar on screen? So like anything it really comes down to
knowing what you are doing, the generic colour settings in the Mac OS aren't
necessarily optimised for dealing with the majority of graphics sources?
The generic profile is almost exactly the same as sRGB, but as I said I haven't checked the gamma. You are right about it coming down to knowing what you're doing, but that's true of any system.
Given the lack of colour aware browsers for the Windows platform can only
assume that the developers don't consider it a problem, it's a pretty sad
situation really.
I think it has its advantages.
In Safari, the colour management only extends to graphics. This is fair enough because you can embed a profile into a picture but not into a web page. So things like text and background colours specified in the HTML are rendered directly in the monitor's colour space (a fancy way of saying the RGB numbers are sent straight from the file to the screen without any processing).
Now consider this scenario, which has bitten me in the past - but only with Safari.
Create an HTML document with a specified background colour of some non-neutral midtone.
Now create a graphic in Photoshop that blends into that background at the edges, and add it into the HTML after saving it with an embedded profile.
When you load the page in Safari, the CMS will convert the image into the monitor's colour space for display. In doing so it changes the RGB numbers. The resultant RGB value of the image background is now slightly different to that of the page background so you will see a discontinuity around the image. If the file was sRGB it won't be as obvious as some other working space.
For this reason I am careful when editing web graphics (not photos) to either save without a profile, or not even colour-manage it in the first place.
I'm sure it'd be possible to add support for a meta tag that specifies a colour space but that would create more problems than it solves.
The fact that you can only get any value out of colour management with a calibrated & profiled system, combined with the difficulty of actually writing a CMM, means that it really isn't worth doing unless the OS provides an easy API to do it for you.
Cheers,
- Dave
http://www.digistar.com/~dmann/
