The PDF is imported with the images converted to pattern as the fill of an object the size of the page with a clipping path the size of the original image. When opening the PDF in Illustrator CS4, the situation is the same (I think) except the images are not upside down.
The PDF is imported with the images converted to pattern as the fill of an object the size of the page with a clipping path the size of the original image. When opening the PDF in Illustrator CS4, the situation is the same (I think) except the images are not upside down.