System for tracking the position of the shooting camera for shooting video films

{
  "publication_number": "US2016127617A1",
  "country": "US",
  "kind": "A1",
  "title": "System for tracking the position of the shooting camera for shooting video films",
  "abstract": "A film shooting system comprises: a camera; a sensor system comprising a first optical sensor system comprising one optical sensor and suitable for recording data in an optical mode, and a second sensor system comprising one sensor, suitable for recording data; a computerised tracking module suitable for incorporating the data from one sensor from the first system and from one sensor from the second system, and for determining location data of the camera from this data; a computerised combination module, suitable for repeatedly determining location data of the camera from both the location data determined in the optical mode and in the second mode.",
  "claims": [
    "1. System for shooting video in a real space defined in a real frame of reference, comprising: a shooting camera, suitable for recording a real image for a plurality of discrete time frames, a sensor system comprising: a first optical sensor system comprising at least one optical sensor that is distinct from the shooting camera and is adapted for recording data in an optical mode; a second sensor system comprising at least one sensor, suitable for recording data; a computerized tracking module suitable for incorporating data from at least one sensor of the first optical sensor system and for determining location data of the shooting camera in the real space based on these data, the computerized tracking module being suitable for incorporating the data from at least one sensor of the second sensor system and for determining location data of the shooting camera in the real space from these data, a computerized combining module suitable for repeatedly determining location data in the real frame of reference of the shooting camera based on both the location data determined in the optical mode and the location data determined in the second mode. 2. Shooting system according to claim 1, wherein the computerized combining module determines the position of the shooting camera by combining the positions determined by the first tracking system, determined by the second tracking system, and a weighting coefficient obtained from C=aA+(1−a)B, wherein the weighting coefficient can have the value 0, 1, or between 0 and 1. 3. Video shooting system according to claim 2, wherein the computerized combining module comprises a computer suitable for determining a difference between the location data obtained in the optical mode and in the second mode, thereby generating a result function, and wherein the computerized combining module also comprises a comparator suitable for comparing the function to a threshold value, thereby generating a comparison function, the comparison function taking a value among a list of values, and wherein the computerized combining module also comprises a selector that receives the comparison function as input and outputs the mode selection signal from a list comprising at least the optical mode and the second mode, respectively corresponding to values of the comparison function, the weighting coefficient taking the value 0 or 1 respectively. 4. Video shooting system according to claim 1, comprising a button suitable for mechanically selecting a mode from the list. 5. Video shooting system according to claim 2, wherein the first optical sensor system comprises an evaluator suitable for evaluating a number of detectable points of natural topographical information detected by the optical sensor, and a reliability module suitable for incorporating the data from the evaluator and outputting a reliability coefficient for the data recorded in optical mode, to enable determining the weighting coefficient for the location data originating from the optical sensor and the sensor. 6. Video shooting system according to claim 3, wherein the selector is suitable for also receiving the reliability coefficient as an input signal. 7. Video shooting system according to claim 1, wherein the second sensor system comprises at least one field-of-view orientation sensor, suitable for determining a mechanical movement resulting in a change of field of view of the shooting camera, and suitable for recording field-of-view change data in a mechanical mode. 8. Video shooting system according to claim 1, wherein the spatial first optical sensor system of the shooting camera comprises at least one optical sensor, providing location data relative to the shooting camera that are known for each time frame, and suitable for transmitting the natural topographical information detected by the optical sensor to the computerized tracking module. 9. Video shooting system according to claim 7, wherein a computerized tracking module compares the natural topographical information detected by the optical sensor, to a predetermined three-dimensional model of the real space. 10. Video shooting system according to claim 1, wherein the tracking system comprises a computerized generation module suitable for generating a predetermined three-dimensional model of the real space, and wherein the optical sensor is suitable for transmitting topographical information detected by said optical sensor to the computerized generation module. 11. Video shooting system according to claim 10, wherein the optical sensor is suitable for transmitting simultaneously to the computerized tracking module and to the computerized generation module, natural topographical information detected by said optical sensor, and wherein the computerized generation module is suitable for enhancing said predetermined three-dimensional model of the real space according to the natural topographical information detected by the optical sensor. 12. Video shooting system according to claim 1, wherein, in the shooting configuration, the shooting camera and the optical sensor are fixedly attached to one another. 13. Video shooting system according to claim 1, wherein the field-of-view orientation sensor is an inertial sensor integral to the shooting camera and suitable for recording data concerning changes in position of the shooting camera. 14. Video shooting system according to claim 13, wherein the inertial sensor comprises a gyroscope or an inertia cube. 15. Video shooting system according to claim 1, wherein the shooting camera is carried by a movable support on a base, and the field-of-view orientation sensor comprises a mechanical encoder attached to the support for the shooting camera and suitable for recording record data concerning changes in position of the support for the shooting camera. 16. Video shooting system according to claim 1, comprising an external mechanical encoder for the internal parameters of the camera suitable for recording data concerning changes in the internal capture parameters of the camera, such as zoom, diaphragm, focal length. 17. Video shooting system according to claim 16, wherein the data concerning changes in the internal capture parameters of the camera are incorporated into the data input to the computerized tracking module. 18. Video shooting system according to claim 1, wherein the computerized shooting module is suitable for integrating the data from the signal of the shooting camera and the internal capture parameters of the shooting camera. 19. Video shooting system according to claim 1, comprising a device suitable for correcting any distortion of the field of view, this device being suitable for incorporating the camera data and outputting the camera data the computerized shooting module. 20. Video shooting system according to claim 3, wherein the first optical sensor system comprises an evaluator suitable for evaluating a number of detectable points of natural topographical information detected by the optical sensor, and a reliability module suitable for incorporating the data from the evaluator and outputting a reliability coefficient for the data recorded in optical mode, to enable determining the weighting coefficient for the location data originating from the optical sensor and the sensor."
  ],
  "description_excerpt": "The present invention relates to systems for tracking the position of a shooting camera for shooting videos.\n\nWhen shooting video, it may be useful to monitor the position and orientation of the shooting camera in real time.\n\nIndeed, especially for video having augmented reality sequences, the camera movement while shooting must be known to allow reproducing it identically on a virtual camera in a computer program, so that when the actual and virtual scenes are merged they give the impression of having been filmed from the same point of view. This information can also be useful for reconstructing an image if a sequence is missing or did not film well for example.\n\nThere are known devices having a spatial tracking system used during shooting via optical sensors. A system marketed under the name of Lightcraft is one example.\n\nIn this system, a sensor captures patterns placed on the ceiling with great precision. However, it is desirable to be able to determine the position of the shooting camera with greater flexibility.",
  "cpc": [
    "H04N 5/2224",
    "G01S 5/16",
    "G06T 17/00",
    "H04N 23/50",
    "H04N 23/695",
    "H04N 5/2254"
  ],
  "ipc": [
    "G06T 17/00",
    "H04N 5/222",
    "H04N 5/225"
  ],
  "assignees": [
    "Solidmanim"
  ],
  "inventors": [
    "Isaac Partouche",
    "Jean-François Szlapka",
    "Robert-Emmanuel LINOT"
  ],
  "filing_date": "2014-06-12",
  "publication_date": "2016-05-05",
  "priority_date": "2013-06-13",
  "application_number": "US-201414897806-A",
  "family_id": "49876721",
  "cited_by_count": 4
}