Machine vision systems ppt
- 4. Simple machine vision system
- 5. 1.Camera 2.light source 3.frame grabber 4.circuitry and programming 5.computer 6.output interface
- 6. COMPONENTS OF MACHINE VISION SYSTEM Image Camera Image capturing system or framegrabber The pre processor The memory The processor The output interface
- 12. 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
- 13. 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.
- 14. 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.
- 15. 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.
- 16. Function of Framegrabber. • Sampling • Quantization • Note : image from videocon camera must be sampled and quantized, images from ccd camera need only quantization.
- 17. Sampling. • Breaks each row of continuous charge reading to column of discrete charge reading.
- 18. Quantization. • Analog to digital converter. • Binary codes are assigned on the level of light.
- 19. Camera with analog-to-digital converter results in digital representation of image
- 20. Mapping of three-dimensional scene into two- dimensional plane
- 21. Depiction of resolution/pixelation; digitally encoded values of shades of grey
- 22. 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
- 23. Advantages • Faster • More consistent • Longer
- 24. APPLICATION
- 31. 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