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COMPONENTS OF MACHINE VISION SYSTEM
Image
Camera
Image capturing system or framegrabber
The pre processor
The memory
The processor
The output interface
CCD (CHARGE COUPLED DEVICE)
• It is a silicon based integrated circuit.
• Image gets focused on chip.
• Charge at each electrode is proportional to exposure to light energy
CCD CAMERA
ADVANTAGES
• More sensitive at low light.
• Produces better image even in extreme variation in brightness
DISADVANTAGES
• Since silicon processing is still new science, so there seems to be variation in light sensitivity from pixel to pixel.
Vidicon camera• Technique used is same as in television.
• The charge in electrode is proportional to amount of light received.
• Does not break image in pixel as CCD camera.
Vidicon camera
advantages
• Is more reliable.
• Low cost.
• Number and arrangement of pixel is in the hand of programmer.
• More flexible.
• Grid and pixel shape can be varied.
disadvantages
• Doesn't break the image in pixel as ccd camera.
• Analog output.
• Imposes constraints on system designer.
Function of Framegrabber.
• Sampling
• Quantization• Note : image from videocon camera must be sampled and quantized,
images from ccd camera need only quantization.
Object Properties in Pixel Grey Value
• Color
a. Hue
b. Saturation
c. Brightness
• Specular properties
I. Reflectance
II.Texture
III.Shading
IV.Shadows
• Non-uniformities
• Lighting
REFERENCES
• Barker, Ronald D., "Managing Yields by Yielding Management to Computers,“
• http://www.dekker.com
• Gehner, William S., "Computer Aided Inspection and Reporting CAIR," Proceedings CAM-I Computer Aided Quality
• Kutcher, Mike, "Automating it All," IEEE Spectrum, May, 1983, pp. 40–43.
• Bravo, P.F. and Kolozsvary, "A Materials Quality System in a Paperless Factory," Proceedings CAM-I Computer Aided Quality Conference, May, 1982, Baltimore, Md., pp. 113–121.
• www.microscan.com
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