sensor array for line detection

[Hester EE]

I found a pretty good sensor that I would like to compare to the cmu camera for line following; only problem is I'm a little lost on how to read in the output from the sensor array. 

This website shows their own way of interpreting the signal, but I don't understand it.  Can anyone explain it to me? thanks
http://www.laurentkneip.de/line_detection.html

[paulstreats]

here is the datasheet for the device http://www.datasheetcatalog.com/datasheets_pdf/T/S/L/1/TSL1401R.shtml

it suggests that a microcontroller should control the clock line.

send a high pulse to the clock, then a high pulse to s1.
bring them both low again.
send the clock high and low 128 times.
for each pulse on the clock line, the a0 pin will output an analog voltage for the next sensor inline until youve read all 128 sensors.

rinse and repeat