Tuesday, 8 January 2008

Optimizing for the web - embedding & tagging

So after 2 pots on the subject (here and here) of colour profiles and web display, turns out I was still wide of the mark.

zeus' comment on my second post

"...am I reading You correctly in sofar that that You think the browser displays the images based on the info found in the EXIF data..."
led me to read even further. I came across this excellent article/series of posts on the subject. If you are new to colour profiles, or want a clear explanation I don't think you'll find a better place to start.

It seems that I was making a glaring assumption concerning colour profiles. I thought that the EXIF tag and the colour profile were inextricably linked. Turns out I was wrong. Each can exist without the other. And it turns out that virtually no applications actually read the tag anyway. I get the idea of the tag - you could use it without embedding the profile and reference a well-known standard profile which your application would already know.

So to my little problem and what I've learnt - I'm still not sure whether Blogger strips out the profile but I'd reckon not. I'm pretty sure EasyThumbnails strips the profile as well as the EXIF when converting from non-JPEG sources. Web pics without a profile will get garbled in some way which is browser dependent: most assume sRGB by default. Safari is currently the only colour aware browser but Firefox 3 is on the way. Embedding sRGB in your web photos is a good idea: it means the conversion has been done and the colours are going to be displayed less screwed-up (but I already knew that going into this little voyage of discovery).

It's about time all photo-image targeted software (including browsers, publishing etc) was properly colour managed then we wouldn't have all this problem.

1 comment:

  1. The articles You referenced by Jeffrey Friedl are indeed clear and understandable. Also a good read is the series on color management published by Andrew Rodney:
    and sccroll down on this page to the articles published in Popular Photography.
    You hit the nail on the head: all software should be color managed, especially everything involved with internet.


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