[NTG-context] blurred shadow on images?

I'd like to place some plain photos rotated (say 12°) and with a blurred shadow above some colored elements, i.e. the shadow must use transparency. I guess I could get such using ImageMagick, but is there a possibility using ConTeXt or one of its favourite friends? I'd prefer a solution that works with CMYK data. If there isn't - is the transparency of PNG usable? Since all of the pictures will have almost the same size, I could probably also use the shadow as a single PDF picture and place that behind with a small offset. Greetlings from Lake Constance! Hraban --- http://www.fiee.net/texnique/ http://wiki.contextgarden.net https://www.cacert.org (I'm an assurer)