This is one command, not a script, but a complex one. The \ at the end of each line are a continuation character. You probably need to remove these and make it all one long line.convert -size 140x80 xc:none -fill grey \
-gravity NorthWest -draw "text 10,10 'Copyright'" \
-gravity SouthEast -draw "text 5,15 'Copyright'" \
miff:- |\
composite -tile - logo.jpg wmark_text_tiled.jpg
The first four lines create a transparent image of size 140x80 and draw gray text in the northwest and southeast corner of that image and output it as miff:- which is an internal temporary image which is then piped to the last line, the composite command which tiles that image (read in as the single -) onto logo.jpg and outputs it as wmark_test_tiled.jpg.