[I said:]
>> [ Note for those who care; Iris RGB and Utah RLE (assumed linear
>> encoding) and TIFF (assumed generic RGB coding) are all 24
>> bit lossless formats. Within the assumptions specified, these
>> 3 can be freely and repeatedly interconverted without information
>> loss, which is why I picked them as examples.]
> Well, often authors include other information in TIFF tags that will
> be lost when you convert to Iris RGB. For most purposes, you don't
> care about those tags, but in a few cases you will.
Sure - which is why I was careful to specify generic rgb. If you have stuff like
scanner whitepoint, phosphor chromaticities, transfer functions etc in there
then clearly that information will be lost. I was just trying not to make it too
complicated...
> Suddenly you might find that `loss' is a vector and not a single
> number. (presentation fidelity, structure retention, invertible
> conversion, etc.)
I agree with this assesment. Asking people to code this vector into every image
URL is clearly asking tooo much unless intelligent editors are ubiquitous -
which we cannot assume - or unless there are well chosen and documented defaults
for when the user does not specify this vector.
-- Chris Lilley +-----------------------------------------------------------------------------+ | Technical Author, ITTI Computer Graphics and Visualisation Training Project | +-----------------------------------------------------------------------------+ | Computer Graphics Unit, | Internet: [email protected] | | Manchester Computing Centre, | Janet: [email protected] | | Oxford Road, | Voice: +44 61 275 6045 | | Manchester, UK. M13 9PL | Fax: +44 61 275 6040 | | X400: /I=c/S=lilley/O=manchester-computing-centre/PRMD=UK.AC/ADMD= /C=GB/ | | <A HREF="http://info.mcc.ac.uk/CGU/staff/lilley/lilley.html">my page</A> | +-----------------------------------------------------------------------------+