Olivier wrote: >In fact, the PNG is converted to JPEG image before to be included in the PDF >file. >But the conversion process doesn't support transparency and sets a black >background.
Jpeg doesn't have transparency. For browsers there is a hack. http://jim.studt.net/jpeg-alpha/ http://stackoverflow.com/questions/14220221/how-to-insert-transparent-png-in-pdf?rq=1 PDF supports transparency since PDF 1.4 To avoid trouble, only use images with the same color space and either a 1 bit mask or a clipping path. Composing images in different color spaces with an alpha channel seems to be difficult to get right. Stephan
