Image conversion method and device using calibration reference pattern
AssigneeIndustrial Technology Research Institute
InventorsYu-Chen Lin, Wei-Cheng Liu, Shao-Yuan Lee
Life of this patent
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Abstract
An image conversion method is provided. An image of a calibration reference pattern is captured. A plurality of first and a plurality of second characteristic patterns of the calibration reference pattern are identified. Coordinates of the first and second characteristic patterns in a first view angle coordinate system are obtained, and coordinates of the first and second characteristic patterns in a second view angle coordinate system are obtained, to obtain a coordinate conversion relationship between the first and second view angle coordinate systems. An input image is converted to an output image according to the coordinate conversion relationship.
Claims20
An image conversion method, for converting a captured input image in a first view angle coordinate system to an output image in a second view angle coordinate system, the method comprising:
- capturing an image of a calibration reference pattern comprising:
- a first calibration reference sub-pattern, comprising a first characteristic pattern group, at least one straight line and a plurality of first grid lines, the first characteristic pattern group having at least two identical first characteristic patterns;
- and
- a second calibration reference sub-pattern, comprising a second characteristic pattern group and a second straight line, the second characteristic pattern group having at least two identical second characteristic patterns, wherein the first characteristic patterns of the first characteristic pattern group are equidistant from a border of the first calibration reference sub-pattern, and the second characteristic patterns of the second characteristic pattern group are equidistant from a border of the second calibration reference sub-pattern;
- identifying the first characteristic patterns and the second characteristic patterns of the calibration reference pattern;
- obtaining coordinates of the first characteristic patterns and the second characteristic patterns in the first view angle coordinate system and coordinates of the first characteristic patterns and the second characteristic patterns in the second view angle coordinate system, to obtain a coordinate conversion relationship between the first view angle coordinate system and the second view angle coordinate system;
- and
- converting the input image to the output image according to the coordinate conversion relationship.
An image conversion device, for converting a captured input image in a first view angle coordinate system to an output image in a second view angle coordinate system, the device comprising:
- an image capturing unit, for capturing an image of a calibration reference pattern comprising:
- a first calibration reference sub-pattern, comprising a first characteristic pattern group, at least one straight line and a plurality of first grid lines, the first characteristic pattern group having at least two identical first characteristic patterns;
- and
- a second calibration reference sub-pattern, comprising a second characteristic pattern group and a second straight line, the second characteristic pattern group having at least two identical second characteristic patterns, wherein the first characteristic patterns of the first characteristic pattern group are equidistant from a border of the first calibration reference sub-pattern, and the second characteristic patterns of the second characteristic pattern group are equidistant from a border of the second calibration reference sub-pattern;
- a characteristic retrieval unit, for identifying the first characteristic patterns and the second characteristic patterns of the calibration reference pattern;
- a coordinate conversion unit, for obtaining coordinates of the first characteristic patterns and the second characteristic patterns in the first view angle coordinate system and coordinates of the first characteristic patterns and the second characteristic patterns in the second view angle coordinate system, to obtain a coordinate conversion relationship between the first view angle coordinate system and the second view angle coordinate system;
- and converting the input image to the output image according to the coordinate conversion relationship.
Dependencies are inferred from the claim text.