You could do a reverse applique with hand stitching. This a technique used in the "Molas" made in Central America. As for enlarging the pattern, I don't know unless you have a printer that you could cut the picture in smaller pieces and then print them enlarged on your printer. Or get an artist friend to grid the picture and draw it on a larger grid to get the larger size. Batik or hand dye fabric would give you the effect of light shining through.