This data type must be changed to 8 bit again, in this case it uses ERDAS Imagine Modeler Maker again with the same procedure
with converting continuous image to thematic image, just change the data type from 16 bit to 8 bit.
The final result can be seen in Figure 4.4, and converting raster to vector will be easy, and then vector analysis will continue by
using ArcView 3.3
Un-scale Image Unchanged Forest
Changed Forest Non Forest
Figure 4.4. The result of classification process that is using ERDAS Imagine
8.7, CART and See5 for period 1990 - 1997
4.1.2. Period 1997 - 2001
Period 1997 – 2001 will be done by the same procedure. Image data 1997 is the same date with image data in period 1990 –
1997, it is 122065_19901109 and 122065_20010512 for image data 2001.
The result of classification process of period 1997 – 2001, is shown in Figure 4.5.
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In this case, with the assumption that deforestation in Period 1990 – 1997 will be non-forest in Period 1997 – 2001, since the
image data 1997 will be the first date and image 2001 will be the second date. Both images become one stacked image.
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Un-scale Raster Unchanged Forest
Changed Forest Non Forest
Figure 4.5.
The result of classification process that is using ERDAS Imagine 8.7, CART and See5 for period 1997 - 2001
By the reason, the deforestation class class number 12 will be clipped by all classes of raster Period 1990 – 1997. Only class
number 12 of Period 1997 – 2001 will be as input theme and Period 1990 – 1997 will be as clip theme. This process is done by using
Modeler Maker ERDAS Imagine 8.7 Figure 4.6. The script as the important part of this model is “EITHER 1
IF n2_Period 1990 - 1997 EQ 12 OR n1_Period 1997 - 2001 OTHERWISE.” In a simple word, It means that “Change class
number 12 in Period 1990 – 1997 to be class number 1 and the remaining class are still same in Period 1997 – 2001.
Figure 4.6. ERDAS Imagine 8.7 Modeler Maker, the model is to clip
deforestation class in first period to the raster in second period. Since in Period 1997 – 2001, there is also class number 12, so if this
class is not changed to another remaining class number for example class number 1; the clipping process will be failure. Before clipping process,
class number 12 of Period 1997 – 2001 was changed to class number 1, by using Recode feature from Raster Tool. The result can be seen in
Figure 4.7.
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Un-scale Raster Unchanged Forest
Changed Forest Non Forest
Figure 4.7.
The result of clipping process between deforestation class in Period 1990 - 1997 will be as non-forest in Period 1997 – 2001.
4.2. Vector Processing
