Term review : bandwidth and file size questions 

 A. Images

   You take a high quality photo with a digital still camera.
   You'd like the 4 inch x 6 inch image to print on 
   a 300dpi (dots per inch) color laser printer, with as 
   much color resolution as you can (24 bits per pixel).
 
     1) How big a file is the raw data for this image?



     2) How big would you expect it to be when saved as 
        a medium quality jpeg?

 B. Audio

   You record 10 minutes of CD quality music.
   Your original data is pretty high quality, 
   without any compression.

     3) What file format might you use?
     4) How big is the raw data file?

   Now you decide to move that high quality data over the network 
   to a friend's computer.

     5) How long does it take to do that over a 56kbps phone line?
     6) How long would it take over a 10Mbps intranet?

   Next you compress it to an mp3 file.

     7) How big is the mp3 file?
 
   And finally you decide to stream it to your friends.

     8) How much bandwidth do you need (in bps) to stream the audio?
        (Divide the size of the file in bits by the time to play it.)

 C. Video

   So let's do some of those calculations with video, eh?

   You record with your camcorder 10 minutes of 
   DV quality video, with one of our school digital cameras.
   The raw data is in a form that FinalCut can edit.

     9) How big is the DV (what comes off the miniDV tape) file?
        Will that fit on a CD?  On a DVD?

    10) How long would it take to move that to another
        computer on the campus intranet, at 10Mbps?

   Now you compress that 10 minutes to DivX format (e.g. mpeg4).

    11) How big is it as a DivX file?  Will that fit on a

   And again you decide to stream it.

    12) How much bandwidth do you need (in bps) to stream the video?
        (Again, divide the size of the file in bits by its run time.)