1800
 0 Citrus
 1600 -1 x Leaf
 "o aBackground
 1400-

 1200 -1 &00

 2 1000-

 g 800 xxx

 600- x

 400 0 x x





 0 50 100 150 200 250 300
 Pixel Value

Figure 4-1. Histogram of 25 calibration images in hue plane (* indicates 3898 pixels of a
pixel value of 0 in citrus class,+ indicates 5606 pixels of a pixel value of 0 in background
class).


 600
 0 Citrus
 x Leaf
 500 -1 aBackground



 400- x


 30 x o
 x ~ x o a
 2300 xx0 0o0
 LL ~ox xx oeoo
 x xo x



 20 5 0 5 0 5 0






 in ciru cls)