Re: [boost] GIL Review

From: Joel de Guzman (joel_at_[hidden])
Date: 2006-11-01 01:07:25

Matt Gruenke wrote:
> Joel de Guzman wrote:
> 
>> Matt Gruenke wrote:
>>  
>>
>>> Joel de Guzman wrote:
>>>    
>>>
>>> I think inventing new terminology is better than overloading or 
>>> hijacking existing terminology.  Furthermore, I believe good names 
>>> accurately describe the concepts to which they refer.  Finally, as a 
>>> user, seeing an unfamiliar term will either prompt me to investigate it 
>>> - or at least to treat it as an unknown, and therefore with appropriate 
>>> caution.
>>>    
>>>
>> I see no overloading or hijacking.
>>  
>>
> 
> The classical definition of color space is not concerned with data 
> layout (i.e. channel ordering).  In many cases, the channel names in 
> common use are heavily overloaded, and are therefore quite inadequate 
> for specifying a color space.

I disagree. A color space is a tuple of numbers. It is concerned with
data and layout as far as I can see. That is the very definition of
"tuple".

> Data format and pixel semantics are orthogonal concepts.  A primary goal 
> of GIL is to separate these concepts.  IMO, the names used in GIL should 
> reflect this.

I agree. That is why I support the idea that color spaces as tuples
where the algorithms are separated from the containers. IOTW,
color spaces are separate from color-space algorithms.

>> That's not my point. Take a look at all the existing libraries
>> that use concepts. Pick one; Vigra seems popular.
>>
> 
> As far as I can tell, GIL does not seek to be only as good as other 
> libraries, in what it does - nor should it.  In fact, its main objective 
> seems to be to take a principled approach to the problem of image 
> representation, access, and conversion and, in so doing, to provide a 
> better foundation for imaging libraries and applications than existing 
> solutions.  Otherwise, why bother?
> 
> Years of programming experience have taught me that semantics matter.  
> Clouded semantics limit extensibility and cause confusion, bugs, and 
> redundancy.  (Ambiguity should be deliberate, and carefully bounded.)

Years of experience has taught me that gratuitous invention of
new terms is not a good thing.

>> "Color Space" *IS* known terminology. That's my point.
>>  
> "known" and "accurate" are distinct criteria.

I agree. And to me "pixel-format" is unknown, confusing and inaccurate.
The worst of the worst. It's like calling a std::vector a data-container
just because the std::vector does not quite follow the "classical" term
of vector. Let's not be too pedantic.

( Clearly, this is getting to be a bicycle-shed, so I'll just let it
be and let the authors do what they think is best. of all things I do
not like are naming games. )

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net