The DISTANCE fuzzy set and ZOOM fuzzy set is given in Table I and II respectively. 

TABLE I DISTANCE FUZZY SET

![0_image_1.png](0_image_1.png)

![0_image_3.png](0_image_3.png)

![0_image_4.png](0_image_4.png)

Distanc e (cm) 
Too Near Near Mediu

![0_image_2.png](0_image_2.png)

Far Too Far 0 Y* N N N N 
4 Y N N N N 5 N Y N N N 
10 N Y* N N N 12 N N Y* N N 15 N N Y N N 20 N N Y N N 25 N N N Y N 30 N N N Y* N 35 N N N Y N 40 N N N Y N 45 N N N N Y 50 N N N N Y* 
TABLE II ZOOM FUZZY SET

![0_image_8.png](0_image_8.png)

Zoom 
(nX) 
Max Zoom Out 

![0_image_6.png](0_image_6.png)

Default Min 

![0_image_7.png](0_image_7.png)

-10 Y N N N N 
-8 Y* N N N N 
-6 N Y N N N 
-4 N Y N N N -2 N Y* N N N 
0 N N Y* N N 
2 N N Y Y* N 4 N N N N N 
6 N N N N N 
8 N N N N Y* 
10 N N N N Y 
 
Example rules that define the five different zooming function based on five different distance input are given in Table III. 
TABLE III RULES FOR ZOOMING FUNCTION

![0_image_10.png](0_image_10.png)

To establish the grade membership, the 'distance' is used as input and the 'zoom' is used as output. Fig. 4 and 5 illustrates the membership function of the input and output variables. 

![0_image_0.png](0_image_0.png)

![0_image_5.png](0_image_5.png)

The fuzzification of the crisp distance gives the following membership for the Distance Fuzzy set as shown in Table IV. 

TABLE IV FUZZIFICATION OF DISTANCE

![0_image_9.png](0_image_9.png)

The Inference yielded DEFAULT x MEDIUM and 

![0_image_11.png](0_image_11.png)

MINIMUM ZOOM IN x FAR. During composition, The MEDIUM and FAR sets have an output of 0.24 and 0.2 respectively as shown in Table IV. 

By applying R4: If Distance is Far then Zoom is Minimize Zoom In and R3: If Distance is Medium then Zoom is Default, the output of fuzzy system can be seen in Fig. 6. 

Figure 6. Composition Defuzzification is the result of the fuzzy logic. Its primary goal is to convert the fuzzy value (an average) to a single number, a crisp value. There are many ways can be used to achieve defuzzifation and in this work, the 'Center of Area' method yielded an answer of 1.7X. The data obtained from 