Advances in camera and video production technology supporting skull-face superimposition: A review

Since the 1980s, advances in camera and video production technology have been substantial. These changes hold relevance to camera-based methods of forensic video superimposition (VS). This especially applies to the last 20 years, where hardware changes have been rapid and provided new improved functionality. This paper reviews these video production advances across the last 40 years (with special attention to the last 20 years) and their impact on, and ramifications for, VS. While the technical advances do not magically resolve all of VS's limitations, such as specific requirements for antemortem reference face images showing teeth etc., they nevertheless help optimize hardware dependent image generation capabilities including: up to 83 × increased spatial sampling for video sequences; up to 6 × increased spatial sampling for still-frame photography in SLR-style camara-body size/footprint; increased spectral resolutions for new recording sensors; new video interrupt recording capabilities that enable direct switching between photographic and video modes in the one device; and new fully-digital software-enabled vision mixing boards that are computer controlled. Importantly, these new hardware advances enable the formerly established, and separately regarded, methods of VS and photographic superimposition to be integrated into a single workflow unifying what were once distinctly separate approaches. This permits the separate advantages of each method to be jointly realised-live motion picture feed that facilitates fast skull positioning and ultra-high-resolution still-frame images for anatomical assessment of skull-face relationships while exactly one vantage point (set by the focus distance of the reference image) is held common between both imaging modalities.