Since it was difficult to grade visualized fingerprints with previously known evaluation methods for the comparison of split fingerprints, a preliminary study was performed with the densitometric image analysis method as a potential quantitative and supplementary evaluation method.
Each images of inked split fingerprints were divided into 4 zones for the analysis. Weekly intra- and inter- analysis by 2 analysts with three whole fingerprints that were constructed by combining inked split fingerprints showed that the average area values and the ranges of difference fluctuation were not significantly different between strong fingerprints and strong-weak pairs, while they were different in weak fingerprints and weak-weak pairs. In the case of weak fingerprints, the exact acquisition of ridges were difficult and this seemed to influence the results. An additional study is needed for the improved reliability using densitometric image analysis with weak fingerprints such as 8 zones division rather than 4 zones. Also the analysis results performed by several analysts at different times should be used to improve the reliability of the analysis method further.
Based on the above result, it can be judged that utilizing the densitometric image analysis method as a secondary evaluation method of the existing scoring system would be effective with the additional studies especially on weak fingerprints.