Calibration apparatus, calibration system, and calibration method
AssigneeSony Interactive Entertainment Inc.
InventorsNoriyuki Yamashita, Akio Ohba
Life of this patent
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Abstract
In a calibration apparatus, a captured image acquisition unit acquires data of an image of a calibration chart captured by a fish-eye imaging apparatus. A distortion correction unit makes an assumption of a parameter of the imaging apparatus, takes into account a projection system to make a correction, and adjusts the parameter until an image of the original chart is obtained. A pseudo image drawing unit uses model data of a chart to draw a pseudo captured image. A point-of-view adjustment unit compares the pseudo image and the captured image and adjusts a point-of-view position of a virtual camera according to a difference between positions of markers or intervals of patterns to specify a position of the imaging apparatus.
Claims19
An apparatus comprising:
- a calibration apparatus including:
- a captured image acquisition unit that acquires data of a captured image of a calibration chart from an imaging apparatus including a fish-eye lens;
- and
- a correction unit that corrects distortion caused by the fish-eye lens based on a relationship between a position on a screen corresponding to the fish-eye lens and a position on a surface of the chart imaged at the position and that evaluates the corrected image to derive and output a value of a parameter regarding the imaging apparatus,
- wherein the correction unit obtains, for each pixel of the captured image, position coordinates on a sphere with a center at a point of view of the imaging apparatus in a three-dimensional space defined by an image plane parallel to the surface of the chart and by a line perpendicular to the surface of the chart and transforms, based on longitude and latitude coordinates of the sphere corresponding to the position coordinates, the position coordinates into position coordinates in a space of the image plane to thereby correct the distortion caused by the fish-eye lens.
An apparatus comprising:
- a calibration apparatus including:
- a captured image acquisition unit that acquires data of a captured image of a calibration chart from an imaging apparatus including a fish-eye lens;
- a parameter acquisition unit that acquires a value of a parameter regarding the imaging apparatus;
- a pseudo image drawing unit that arranges a virtual camera and an object model of the chart in a virtual three-dimensional space and that uses the value of the parameter to generate a pseudo image of the captured image as an image captured by the virtual camera;
- and
- a point-of-view adjustment unit that compares the generated pseudo image and the captured image to derive a position of the imaging apparatus with respect to the chart.
A calibration method, comprising:
- acquiring data of a captured image of a calibration chart from an imaging apparatus including a fish-eye lens;
- correcting distortion caused by the fish-eye lens based on a relationship between a position on a screen corresponding to the fish-eye lens and a position on a surface of the chart imaged at the position;
- and
- evaluating the corrected image to derive and output a value of a parameter regarding the imaging apparatus,
- wherein the correcting distortion includes obtaining, for each pixel of the captured image, position coordinates on a sphere with a center at a point of view of the imaging apparatus in a three-dimensional space defined by an image plane parallel to the surface of the chart and by a line perpendicular to the surface of the chart and transforms, based on longitude and latitude coordinates of the sphere corresponding to the position coordinates, the position coordinates into position coordinates in a space of the image plane to thereby correct the distortion caused by the fish-eye lens.
A non-transitory, computer-readable storage medium containing a computer program, which when executed by a computer, causes the computer to carry out actions, comprising:
- acquiring data of a captured image of a calibration chart from an imaging apparatus including a fish-eye lens;
- correcting distortion caused by the fish-eye lens based on a relationship between a position on a screen corresponding to the fish-eye lens and a position on a surface of the chart imaged at the position;
- and
- evaluating the corrected image to derive and output a value of a parameter regarding the imaging apparatus,
- wherein the correcting distortion includes obtaining, for each pixel of the captured image, position coordinates on a sphere with a center at a point of view of the imaging apparatus in a three-dimensional space defined by an image plane parallel to the surface of the chart and by a line perpendicular to the surface of the chart and transforms, based on longitude and latitude coordinates of the sphere corresponding to the position coordinates, the position coordinates into position coordinates in a space of the image plane to thereby correct the distortion caused by the fish-eye lens.
Dependencies are inferred from the claim text.