Re: [boost] VIGRA - Image processing for boost

From: Peter Dimov (pdimov_at_[hidden])
Date: 2001-11-17 07:54:54

From: "Fernando Cacciola" <fcacciola_at_[hidden]>
> It seems that our only disagreement is whether a binary image should be
> considered as a different case and not as a special case.

What would you gain by considering a binary image a different case?

> IOW, if I would consider a binary image as a special case then I would
> certainly agree with the basic_image<bool,xxx> interface.
> It is not your interface what I don't like, but the generalization you are
> implying with it.

Sorry, could you elaborate on that a bit?

> Anyway, I'm not an expert, so I can be plain wrong; and even if I were an
> expert and were theoretically right,
> we are discussing the interface of a practical library, so if users would
> prefer your view of a binary image as
> just a special case of a color image then your interface is correct;
> however, if users would prefer my view of
> a binary image as a separte entity,
> then I suggest "basic_color_image<pixel_type,encoding> and
> basic_binary_image<encoding>"

Again, what would you gain by making basic_binary_image<> a separate class
rather than a specialization of basic_image<>?

> > This allows generic algorithms to still operate on bitonal images
> > unmodified, while in the same time allowing you to replace some with
> > specialized versions.
>
> How the choice of 'basic_image<bool>' vs 'basic_binary_image<>' could
affect
> the generality
> of the algorithms?
> Do you mean that those algorithms would take template template parameters?

If you have an algorithm that takes basic_image<> and this algorithm does
not need to treat binary images as a distinct case but happens to work on
them as is, you don't have to supply a specialization for it.

In the basic_binary_image<> case, you have to reimplement all algorithms no
matter whether the generic version would do the job as well.

--
Peter Dimov
Multi Media Ltd.