An automated method for the generation of bloodstain pattern metrics from images of blood spatter patterns

An improved automated bloodstain pattern analysis method has been developed and validated, which utilises computer vision techniques to identify bloodstains on a plain background within a digital image. The method generates metrics relating to the individual stains as well as the overall pattern, including bloodstain pattern specific metrics such as the gamma angle, circularity, solidity, area of convergence, stain density and pattern linearity. This method provides an objective approach to the analysis of bloodstains and bloodstain patterns and can generate a wealth of quantitative data that is currently not obtainable using manual techniques or other image-based programs currently utilised in the discipline. This method will be useful to analysts and researchers investigating the application of quantitative methods to bloodstain pattern analysis. •A method that automatically analyses digital images of bloodstain spatter patterns is described.•Improved stain segmentation detects even very small stains under varied lighting conditions.•A novel approach to fitting ellipses allows for accurate BPA specific metrics to be calculated.•Quantitative data is quickly and reliably extracted from patterns increasing objectivity.