"Paul McGuire" <[EMAIL PROTECTED]> wrote: | "H J van Rooyen" <[EMAIL PROTECTED]> wrote in message | news:[EMAIL PROTECTED] | > "Paul McGuire" <[EMAIL PROTECTED]> wrote: | > | > | Even downer-and-dirtier, you could approximate 30 with 32, 59 with 64, | and | > | 11 with 8, and do bit-shifting instead of multiplying: | > | | > | def darkness(img,x,y): | > | return (RedVal(img,x,y) << 5) + (GreenVal(img,x,y) << 6) + | > | (BlueVal(img,x,y) << 3) | > | | > | | > | -- Paul | > | > *grin* - a man after my own heart! - how do you multiply by ten? - shift, | save a | > copy, shift twice more and add the copy... | > | > - Hendrik | > | Sadly, my timeit results show this saves only a little time, and | shift-copy-shiftsomemore-and-add is even slower then just doing the original | floating point multiply. The biggest win is in prelookup of Image.GetXXX | functions. | | -- Paul
I was not seriously suggesting this for use in python on a pc - its the sort of rubbish you do on a small embedded machine that has a reduced instruction set and no multiplier... - Hendrik -- http://mail.python.org/mailman/listinfo/python-list
