detection of empty shreds

This program contains a function "isEmpty" that takes in a Bitmap of a shred and returns a boolean value to indicate if the shred is empty.

The function is very simple. It first finds the Histogram of the image. Then it goes through the histogram and Tally's up the zeros that it encounters. Shreds that are empty tend to have way more zeros than shreds with text on them. This is becuase text fills up the color range (0-100) which are the color values that dark text has.

The threshold of 80 zeroes is based on experimental evidence from 70 shreds and it is more likely to provide a false negative than a false positive.