Yes sorry, the example was quickly written. In some cases, alpha is zero but we want to keep the pixel data, that why I would like to disable premultiplication. 2010/4/12 Lubomir Bourdev

Hi Eloi,

One solution is to define your own color space “rgba_premultiplied_t” and provide color conversion functions from/to it.

In your example, did you mean to use rgba32f_pixel_t ? Also wouldn’t p1[3]=0.0f set the alpha to zero? In this case the color is fully transparent. I am not sure what you would expect...

Lubomir

On 4/12/10 6:38 AM, "Eloi Du Bois" wrote:

Hi all,

I am working on rgba32f view that have alpha values of 0. I need to apply a color_convert but it drops the values because of the 0 alpha valued. How can I disable alpha premultiplication ? If impossible, it should be a good idea to give a choice on copy_and_convert & color_convert.

code sample: rgb32f_pixel p1, p2; p1[0] = 1.0f; p1[3] = 0.0f; color_convert(p1, p2); assert(p1[0] == p2[0]);

Thank you by advance, Eloi Du Bois.

_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users