Re: Constraints and Functional Dependencies

On Feb 28, 11:14 pm, paul c <toledobythe..._at_oohay.ac> wrote:
> Sampo Syreeni wrote:
> > On 2007-02-28, paul c wrote:
>
> >> 2) When inserting a TIF image of one person or a JPG of the same
> >> person, is there a way an engine could consider the TIF and JPG equal?
> > ...
> > That means the end user never wants to use an equality predicate in a
> > query, because even a query aiming at a single answer (conventionally
> > "select x from y where y.attribute=known_value") would most likely
> > search on a probabilistic/fuzzy predicate (i.e. "select x from y where
> > y.attribute most like known_value). ...
>
> What is probalistic about it? I thought I could convert the same TIFF
> to a JPEG twice and get the same JPEG both times.
A little info about image files...
JPEG is a *destructive* compression algorhythm for bitmap based images.
destructive meaning that each time one saves under JPG format there is loss of information as to the initial bitmap format. Each time, one opens a JPG the file is decompressed but one does not get the original bitmap file. TIFF on the other hand is non destructive but less size efficient.

> p
Received on Thu Mar 01 2007 - 09:32:37 CET