Lossless JPEG2000 to PDF Compression, part 2

How do I losslessly compress lossless JPEG2000 files to pdf without losing any quality?

Another thing, my images are 96 dpi and have a resolution of 1920x1080, but when I put them in a pdf file and exported them, I had to use 72 dpi instead of 96 dpi to match/get the right resolution from the input/ How do I fix that?