Hi there, I'm in Cuda school this week. Please allow me some time to have a look at this over the weekend. Regards, Christian On Wed, Jul 28, 2010 at 5:49 AM, <fabien.castan@free.fr> wrote:
Hi,
I use the GIL extension: HSL. I need to make conversions from hsl to other colorspaces. So I define generic default conversion using intermediate rgb colorspace. I define 2 templates: * default_color_convert<C1,hsl_t> * default_color_convert<hsl_t,C2>
But it creates an ambiguity with rgba_t, because it defines the same thing for rgba_t: * default_color_convert<C1,rgba_t> * default_color_convert<rgba_t,C2>
So default_color_convert<hsl_t,rgba_t> is ambiguous.
The only solution I see is: * to remove default_color_convert<C1,rgba_t> * to define gray_t->rgba_t, rgb_t->rgba_t * to remove default_color_convert<C1,hsl_t> * to define default_color_convert<cmyk_t,C2>
So all colorspaces have to: * define a generic conversion to another colorspace using an intermediate rgb colorspace conversion * redefine the conversion for colorspaces we want to make a direct conversion
Best regards,
Fabien Castan
/// \ingroup ColorConvert /// \brief Converting CMYK to any pixel type. Note: Supports homogeneous pixels only. /// /// Done by an intermediate RGB conversion template <typename C2> struct default_color_converter_impl<cmyk_t,C2> { template <typename P1, typename P2> void operator()(const P1& src, P2& dst) const { typedef cmyk_t C1; typedef typename channel_type<P1>::type T1; typedef typename channel_type<P2>::type T2; pixel<T2,rgb_layout_t> tmp; default_color_converter_impl<C1,rgb_t>()(src, tmp); default_color_converter_impl<rgb_t,C2>()(tmp, dst); } };
/* /// \ingroup ColorConvert /// \brief Converting any pixel type to RGBA. Note: Supports homogeneous pixels only. template <typename C1> struct default_color_converter_impl<C1,rgba_t> { template <typename P1, typename P2> void operator()(const P1& src, P2& dst) const { typedef typename channel_type<P2>::type T2; pixel<T2,rgb_layout_t> tmp; default_color_converter_impl<C1,rgb_t>()(src,tmp); get_color(dst,red_t()) = get_color(tmp,red_t()); get_color(dst,green_t())= get_color(tmp,green_t()); get_color(dst,blue_t()) = get_color(tmp,blue_t()); get_color(dst,alpha_t())= channel_convert<T2>(alpha_or_max(src)); } }; */
/// \ingroup ColorConvert /// \brief Converting grayscale pixel type to RGBA. Note: Supports homogeneous pixels only. template <> struct default_color_converter_impl<gray_t,rgba_t> { template <typename P1, typename P2> void operator()(const P1& src, P2& dst) const { typedef gray_t C1; typedef typename channel_type<P2>::type T2; get_color(dst,red_t()) = get_color(src,gray_color_t()); get_color(dst,green_t())= get_color(src,gray_color_t()); get_color(dst,blue_t()) = get_color(src,gray_color_t()); get_color(dst,alpha_t())= channel_convert<T2>(alpha_or_max(src)); } };
/// \ingroup ColorConvert /// \brief Converting grayscale pixel type to RGBA. Note: Supports homogeneous pixels only. template <> struct default_color_converter_impl<rgb_t,rgba_t> { template <typename P1, typename P2> void operator()(const P1& src, P2& dst) const { typedef rgb_t C1; typedef typename channel_type<P2>::type T2; get_color(dst,red_t()) = get_color(src,red_t()); get_color(dst,green_t())= get_color(src,green_t()); get_color(dst,blue_t()) = get_color(src,blue_t()); get_color(dst,alpha_t())= channel_convert<T2>(alpha_or_max(src)); } };
/// \ingroup ColorConvert /// \brief Converting RGBA to any pixel type. Note: Supports homogeneous pixels only. /// /// Done by multiplying the alpha to get to RGB, then converting the RGB to the target pixel type /// Note: This may be slower if the compiler doesn't optimize out constructing/destructing a temporary RGB pixel. /// Consider rewriting if performance is an issue template <typename C2> struct default_color_converter_impl<rgba_t,C2> { template <typename P1, typename P2> void operator()(const P1& src, P2& dst) const { typedef typename channel_type<P1>::type T1; default_color_converter_impl<rgb_t,C2>()( pixel<T1,rgb_layout_t>(channel_multiply(get_color(src,red_t()), get_color(src,alpha_t())), channel_multiply(get_color(src,green_t()),get_color(src,alpha_t())), channel_multiply(get_color(src,blue_t()), get_color(src,alpha_t()))) ,dst); } };
/// \ingroup ColorConvert /// \brief Converting HSL to any pixel type. Note: Supports homogeneous pixels only. /// /// Done by an intermediate RGB conversion template <typename C2> struct default_color_converter_impl<hsl_t,C2> { template <typename P1, typename P2> void operator()(const P1& src, P2& dst) const { typedef hsl_t C1; typedef typename channel_type<P1>::type T1; typedef typename channel_type<P2>::type T2; pixel<T2,rgb_layout_t> tmp; default_color_converter_impl<C1,rgb_t>()(src, tmp); default_color_converter_impl<rgb_t,C2>()(tmp, dst); } };
/// \ingroup ColorConvert /// \brief Unfortunately HSL to HSL must be explicitly provided - otherwise we get ambiguous specialization error. template <> struct default_color_converter_impl<hsl_t,hsl_t> { template <typename P1, typename P2> void operator()(const P1& src, P2& dst) const { static_for_each(src,dst,default_channel_converter()); } };
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