No announcement yet.

Terminology: "Stereovideometric system"

This topic is closed.
  • Filter
  • Time
  • Show
Clear All
new posts

  • Terminology: "Stereovideometric system"

    Dear subscribers,

    as you know, "stereophotogrammetric system" (SPM system) has a generic
    meaning (see etymology below). SPM systems include systems which measure
    static objects:
    - Based on film photography
    - Based on digital photography
    - Roentgen SPM systems (3-D radiography or fluoroscopy)
    (radiographies or fluoroscopic images are a special kind of "photograms")
    And also systems which measure "motion" (a time sequence of positions):
    - Cinematographic systems
    - Analog-video-based optical SPM systems
    - Digital-video-based optical SPM systems
    - (3-D video-fluoroscopy? I am not sure if this is used to analyze motion)

    These systems are quite different from each other, as far as their accuracy,
    applications, drawbacks and advantages are concerned. Indeed, we often use
    the expression "optoelectronic SPM system", to distinguish systems based on
    analog video, digital video or digital photography from those which are not
    optical (radiographic or fluoroscopic systems) or not electronic (systems
    which require image recording on photographic film).

    But sometimes we need a greater specificity. For instance, one of the most
    specific expressions I have ever read was used by Chiari et al. (2005). They
    wrote "video-based optoelectronic stereophotogrammetric system". I shortly
    discussed this terminology with one of the authors (A. Leardini), and he
    explained their rationale: "optoelectronic" was necessary to exclude the
    above mentioned non-optoelectronic systems, but it was not enough to
    uniquely identify systems for motion analysis: digital photographic cameras
    are optoelectronic. These distinctions were relevant in the context of their
    article, which was about instrumental errors. Thus, both the words "video"
    and "opto" (or "optical") were necessary. However, the expression is
    redundant because "video-based" implies "electronic", and implies the use of
    a sequence of "photograms" (see etymology below).

    In sum, in biomechanics there is a need for expressions to indicate
    particular kinds of SPM systems, for instance those which can be used for
    human motion analysys (HMA), and are based on electronic technology (as
    opposed to cinematographic technology). Since the term "video" refers to
    electronic motion recording (see etymology below), let's call these systems
    "stereovideometric systems" (SVM systems). In sum:

    - "SPM system" is too generic to uniquely identify a system for HMA
    (it includes
    - "Optoelectronic SPM system" is more specific, but not enough to specify a
    system for HMA.
    - "SVM system" is specific enough.
    - "Video-based optoelectronic SPM system" is even more specific, but
    - "Video-based optical SPM system" is equivalent to the previous expression,
    but shorter.
    - "Optical SVM system" is equivalent to the previous expression, but even

    The term "videometry" and the expression "digital videometry" are frequently
    used in the scientific literature; a search with
    confirms this). Notice that "video" implies "electronic", but neither
    implies "optical" nor "digital" (video-fluoroscopes are not optical, and
    analog video cameras are not digital). If you need to be more specific, you
    can use "digital optical SVM system", and you can add other specifications
    such as "passive-marker", "active-marker", or "markerless".

    I conclude that the term "stereophotogrammetric" (SPM) is too generic in
    many circumstances, and "stereovideometric" (SVM) is useful whenever SPM is
    too generic. Thus, I propose to include this term in our vocabulary.

    Stereophotogrammetric =
    [stereo, from Greek stereos = solid] +
    [photogram = 2-D image recorded by capturing light photons or X-ray
    from Greek fos (genitive: fotòs) = light and grafèin = to
    write] +
    [metric = related to a measure or used to measure, form Greek metron =

    Stereovideometric =
    [stereo, from Greek stereos = solid] +
    [video = electronic (not necessarily optoelectronic) technology, to
    motion with a sequence of 2-D images, from Latin video = I see]
    [metric = related to a measure or used to measure, form Greek metron =

    Optical = related to vision or to optics, the science that describes the
    behavior and properties of light and its interaction with matter (from Greek
    optikòs = related to vision, in turn from òps = eye).

    Chiari L, Della Croce U, Leardini A, Cappozzo A. (2005). Human movement
    analysis using stereophotogrammetry. Part 2: instrumental errors. Gait &
    Posture 21(2):197-211. (Review)

    With kind regards,

    Paolo de Leva
    Laboratory of Locomotor Apparatus Bioengineering
    Department of Human Movement and Sport Sciences
    University of Rome - Foro Italico