7.7 Analysis
We went through the analysis process in the last chapter.
Possible Matches
Let the Total Images in the input file be N, the Possible Matches will be N*N. In our example, N * N = 304 * 304 = 92,416.
Attrasoft Matches
The number of retrieved matches is listed in the last line of b1.txt. Go to the end of b1.txt, you will see something like this:
Total Number of Matches = 8320
Actual Match
This number depends on your problem. It should be the first number in b1_matchlist.txt. In our example, it is 608.
Attrasoft Found Duplicates
To check the results, we must prepare the b1_matchlist.txt file now. This file is already prepared for you and we will simply open it and save it to b1_matchlist.txt (overwrite the existing file). The steps are:
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Open Windows “c:\program files\Attrasoft 7.0\data\b1_ matchlist_ex_label.txt”.
Save it to "b1_matchlist.txt (over write the exisitng file). Now this file is prepared.
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Click "BioFilter\N:M Analysis\Check (b1_matchlist.txt) to check results of the BioFiler. .
The result is:
Total Matches = 608
All of the pairs are identified. Now that you have all of the numbers, you can make an analysis.
Positive Identification Rate
In this example, the Positive Identification Rate is 100%, i.e., 608/608 = 100%.
Elimination Rate
Elimination Rate = 91 % = (1 – 8320/92,416).
Hit Ratio
The Hit Ratio = 608/8320 = 8.2 %.
Composite Index
The composite index is = 100% * 91% * 8.2% = 7.5%.
The composite index is low, largely because it retrieved 8320 images. This can be improved in many ways, such as:
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Setting a Threshold higher than 0;
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Setting other parameters;
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Choose a more accurate Signature Filter;
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Choose a Neural Filter.
We will discuss these topics later.
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