| The tyre trace evidence are routinely left at crime scenes of an traffic accident, whichconsist of tire tread pattern impressions, tire sidewall patern impression, tread conpoundresidue, wheelbase and track width. The examination of detailed tire trace evidence result notonly in the positive identification of tire(s) and type of vehicle from the suspect(s)' vehicle(s),but also in deducing collision point, true reasons and the process of accident, velocity ofvehicles and verifying credibility and truth of other evidences. Therefore,the tire traceevidences on scene are one of effective trace for suspects' vehicle geographical origintraceability．In this paper, the trace evidence of suspects' vehicle tire on scenes is the principleresearch object. The statistical analysis of wheelbase,tread width and parameters of selectedtire, identification technologies of tires residues, class characteristics and influencing factors,image edge detection, feature extraction and matching technologies of the vehicles' tire treadpattern are studied, and the traceability technologies of vehicle are integrated, the results ofresearch are provided technical assistances for traffic accident treatment and solving accidentcases.Tire pressure, braking process and objects influence on the characteristics of tireimpressions by analysis of the vehicles' tire impression at different conditions. Width of tireimpression and width of the vertical grooves decrease with reduction of tire pressure. In thebraking process, the tire impressions transform tyreskidmarks from the rolling impression,while tire impressions of vehicles with ABS are discontinuous. Tread patterns, distance andsharpness of the tire impressions are different on the objects with different mechanicalproperties and surface conditions.The wheelbase and tire width of suspects' vehicle are measured with tire trace on thetraffic scene. The regularities of the different264vehicle types' wheelbase, front/rear wheeltrack is little by statistical analysis on the wheelbase and front/rear wheel track of differentvehicle types.By researching on tire imprint, as stable features of vehicle traceability, the tireimpressions' class characteristics of the different vehicle type have been conclused, includingwidth of impression, future and distance of tread pattern and etc.By the analysis of pyrolysis-gas chromatography analysis on tire tread rubber residue ofdifferent10vehicle type and trademark, the rubber kind, rubber content, and content of carbon black, ash, additives are calculated which are diffirent among10different brand type.All of them could be used for suspects' vehicle geographical origin traceability.On the basis of analysis on curve evolution, level set method, variational principles andtraditional C-V model, an improved image segmentation algorithm without re-initialization isdeveloped in the energy function by introducing an internal energy term that penalizes thedeviation of the level set function from a signed distance function into the C-V model. Thesegmentation results of the improved C-V model are similar to those of traditional C-V model,but the consumption time is less.On the basis of analysis the principle of SIFT transformation, combined with Gaborwavelet transformation, the tire tread pattern images features extraction, matching algorithmsbased on SIFT-Gabor transformation and the pattern recognition algorithms based onnearest-neighbor statistical method are proposed. The results of experiment show that thematching cost time of the Gabor-SIFT algorithm is less than that of standard SIFT algorithmby reducing dimensions of feature vector. The improved algorithm has higher matchingaccuracy and needs less cost time, it is quite suitable for tire tread pattern images matching,which indicate that all of them can be used for the suspects' vehicle traceability.The functions, database structure and interfaces of the suspects' vehicle traceabilitysystem prototype which is integrated with Visual C++6.0are designed on the basis oftechnicians' requirement.
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