Re: Re : Image quality on web

Chris Lilley, Computer Graphics Unit (
Mon, 21 Nov 1994 22:34:56 +0100

Joel Crisp said:

>Chris Lilley said:

> > Whatever, things give off light which has a defined spectrum and can thus be
> > reduced to an XYZ triple.

> In about 30 different and incompatable ways.

Put politely, BS. A single light spectrum can be reduced to an XYZ in precisely
two ways, for either a 2 degree or a 10 degree observer. The latter is rarely
used, which leaves one way.

XYZ is a reproducible and measureable colour description which has been an
international standard for the last 63 years.

>> Unless you have some direct experimental evidence to cite, I think you
>> overstate the case. What I want to avoid is a collective response of,
>> "oh, this is too hard, it is impossible, let's not bother, here is an
>> RGB file".

> This is certainly not what I'm trying to say. I would hope that people will
> not rush into saying TIFF is *the* solution for all time.

Ah. OK, that is not what *I* was trying to say. I just threw up a rag bag of
technology that might bear upon the problem and, as it happens, TIFF does do
quite a lot of good things. Clarification, the TIFF spec does ;-)

But I did not mean to present TIFF as a universal panacea.

> I believe that
> as wide a view of the potential problems should be aired as possible before
> we shoot ourselves in the foot. I am quite prepared to accept existing
> standards as time proven, but I do think that some thought for the
> future needs to be discussed.


>> Well understood solutions do exist that would bring a great improvement
>> over the current situation. Let us implement these, and implement them
>> well, and proceed from there, rather than give up in despair.

> Fine by me, so long as they are expandable and people accept that things
> will change.

Qoute from the Tagged Image File Format spec again, just as an example you
understand ;-)

"A tag based scheme cannot guarantee painless growth. But it does provide a
useful tool to assist in the process"...

" TIFF will be enhanced on a continuing basis as new imaging needs arise. A high
priority has been given to structuring the data in such a way as to minimise the
pain of future additions"

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