Subject: Re: [boost] [GIL] color_convert
From: fabien.castan_at_[hidden]
Date: 2010-08-06 06:15:34


Hi Christian,

> Only for rgba gil is using partial specialization since it's using the
> rgb equivalent to do the wanted conversion. I think it's best to stick
> with total specialization to avoid confusions and/or breaking other
> people's code.
>
>> The goal of creating this generic conversion is that I can still make the conversion using an intermediate rgb colorspace if there is no specialization.
> I think I just said that. ;-)

For me, we can do that for all colorspaces.

Sorry, I'm not sure to understand your position.
You are agree to remove total specialization, even for rgba ?
Are you agree to create a generic conversion from Colorspace to C2 for all colorspaces ?
default_color_converter_impl<C1,rgba_t> // to remove
default_color_converter_impl<rgba_t,C2> // do the same thing for all colorspace

> Even when converting from gray to cmyk you wanna create a temporary
> rgb value? I believe this is a bad idea for various reasons. Please
> correct me when I'm wrong.

I think there is only two problems:
* approximation
* performance

But if we want to correct these problems we have only to create the missing specialization. So I don't see any problem.
It's always interesting to have all conversions. I don't think we will have a specialization to make the conversion from hsl to cmyk in a near futur.
So in these cases propose a solution with approximation and performance cost sounds good to me.
And it works fine with user custom colorspaces.

Regards,
Fabien