Video Superimposition
Definition
The updated superimposition workflow using a motorised skull turntable, a calibrated video camera, and real-time electronic mixing of the skull video image with the portrait photograph. Replaced the original photographic-transparency method from the 1970s-1980s onward.
- Transparency blend ratio
- 50:50 (equal mixture of skull video and photograph)
- Key advantage
- Real-time landmark alignment with motorized skull positioning
Common questions
How does video superimposition work in skull analysis?+
The examiner sets a camera to film the oriented skull, then overlays the video feed onto a scanned antemortem photograph in real-time using a video mixer. The images are blended at 50:50 transparency, making it easy to align anatomical landmarks between the skull and the portrait photo.
What equipment is used in modern video superimposition?+
The setup uses a motorized skull turntable to position the skull, a calibrated video camera to capture it, and electronic mixing equipment to blend the live skull feed with a scanned photograph. This replaced the older photographic-transparency method.
Why use video superimposition instead of just comparing photos side by side?+
Real-time electronic mixing lets you align specific skull features to photograph landmarks with precision, and the 50:50 transparency blend reveals how well they match. You can rotate the skull on the turntable and watch the alignment change, making it much easier to assess whether a skull and portrait belong to the same person.
Related terms
- Gonion
- The most posterior and inferior point of the mandibular angle, bilaterally. Used in superimposition to assess the width of the jaw angle...
- Nasion
- The anatomical landmark at the junction of the nasal bones and the frontal bone (the bridge of the nose). One of the...
- Anatomical Landmarks
- Fixed cranial reference points (about 25 are used) including glabella, nasion, gonion, gnathion, zygion and prosthion that must align with corresponding soft-tissue...
- AnthropoScope
- Computerised three-dimensional skull and facial reconstruction system using laser scans of the skull and soft-tissue prediction from CT databases.
- Consistent with
- The categorical superimposition conclusion that examined morphological features do not exclude the skull as deriving from the same individual as the portrait....
- Exclusion
- The categorical conclusion that one or more examined features are clearly inconsistent in a way that cannot be explained by projection angle,...
- FACES
- American computerised composite and reconstruction software (IQ Biometrix) used to generate two-dimensional faces from cranial and witness data.
- Frankfurt Horizontal Plane
- The anatomical reference plane defined by the upper border of the external acoustic meatus and the lowest point of the orbital margin...
- Glabella
- The midline prominence on the frontal bone between the superciliary arches. Scored 1 (flat, female) to 5 (highly prominent, male). Correlated with...
- Glaister-Brash Method
- The original photographic-transparency superimposition protocol developed by John Glaister Jr and James Couper Brash for the 1935 Buck Ruxton case in Lancaster...
- Gnathion
- The most inferior point of the mandibular symphysis in the midline, corresponding to the tip of the chin in the portrait photograph....
- Iscan-Helmer 1993
- The edited volume 'Forensic Analysis of the Skull' (Iscan and Helmer, Wiley-Liss, 1993) that brought together the first systematic reliability assessment of...
Explained in these topics
- Photo-Skull and Video SuperimpositionThe updated superimposition workflow using a motorised skull turntable, a calibrated video camera, and real-time electronic mixing of the skull video image wit...
- Skull Superimposition and Facial ReconstructionLive mixing of a camera feed of the oriented skull with a scanned antemortem photograph on a video mixer at 50:50 transparency, allowing real-time landmark ali...