Authors:
Sungho Suh
and
Moonjoo Kim
Affiliation:
Samsung Electro-Mechanics, Korea, Republic of
Keyword(s):
Automatic Calibration of the Optical System, Passive Component Inspection, Gain, White Balance Ratio.
Related
Ontology
Subjects/Areas/Topics:
Computer Vision, Visualization and Computer Graphics
;
Device Calibration, Characterization and Modeling
;
Image Formation and Preprocessing
;
Image Formation, Acquisition Devices and Sensors
Abstract:
A passive component inspection machine is to obtain a image of a passive component by using a specific
lighting and camera, and to detect defects on the image of the component. It inspects all the aspects of the
component based on the image which is captured by using the lightings and cameras. The number of the
lightings and cameras are proportional to the number of the component aspects. To detect the defects of the
component effectively, the difference between the image quality by each camera should be minimized. Even
if the light conditions are calibrated automatically, the average intensities of the images are different because
of influence of Bayer filter which is used in CCD camera in the passive component inspection machine. Moreover,
there is one more problem that the range of the light intensity cannot cover the range of the component
reflectance. Sometimes, it is needed to calibrate a gain value and white balance ratios of the camera manually.
In order to solve the problems
, we propose an automatic calibration method of the optical system in passive
component inspection machine. The proposed method minimizes the influence of Bayer filter, does not use
any initial camera calibration, and find the optimal values for the overall gain and white balance ratios of red,
green, blue colors automatically. To reduce the influence of Bayer filter, we perform to find the optimal values
of all colors balance ratio iteratively and formulate a relation between the overall gain and the white balance
ratios to control all the parameters automatically. The proposed method is simple and the experimental results
show that the proposed method provides faster and more precise than the previous method.
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