Similarity Measurement of Striation Marks Based Upon the Longest Common Subsequence Method

Similarity comparison of striation marks plays an important role in striation mark analysis. The cross-correlation technique is used to measure the similarity of two striation tool marks. But this method is time-consuming and scale-dependent. In this paper, a striation mark manufactured by a screwdriver can be converted into a pattern of alternative bright and dark lines (“similar” to a barcode). We build a striation pattern feature based upon the distance of adjacent bright lines, and denote the feature by a sequence. We use the longest common subsequence (LCS) method to compare the similarity of sequences of striation marks. The LCS method provides a good way for measuring the similarity between sequences. The advantage of making use of the LCS method is easy and efficient. The 1-D strings can also reduce the storage space of database. From the experimental results, the LCS method provides feasibility to describe the similarity between two striation marks.