1. 240-373 Image Processing1 Image Acquisition Photo sensors –Photo diodes and photo diode array –Photo transistor Video camera

2. 240-373 Image Processing2 Primitive camera structure Slotted board, rotating disc Photosensitive device Lens Illumination for object

3. 240-373 Image Processing3 Vidicon

4. 240-373 Image Processing4 Color Images involves the capture of 3 images simultaneously, r,g,b placing filters over the lens of the camera is unsatisfactory Use color stripes placed between lens and photo sensor

5. 240-373 Image Processing5 Video Image Capture use a device call --frame grabber-- r g --> 8-bit video A/D --> color converter--> mem --> color converter -- >video DAC --> g b ADC = 6 million conversion/sec, 160 ns per conversion

6. 240-373 Image Processing6 Real-time capture 25 frame/second minimum to avoid flickering Must be done electronically Example to grab image of 500x500 dot with 256 grey levels requires 6.25MB per sec. Require lots of resources

7. 240-373 Image Processing7 Image Scanner Flat bed Hand-held for still images only mechanical accuracy can be a problem

8. 240-373 Image Processing8 Charge-Coupled Device (CCD)

9. 240-373 Image Processing9 Image Display Display monitors –CRT (Cathode-ray Tube) -based on R, G, B colors -Cannot display all colors that human can see -Black is not real black and white is not real white –LCD (Liquid Crystal Display) -Light weight -Low power consumption -Slow

10. 240-373 Image Processing10 Image Display Printers (mention dithering and patterning) –Dot matrix printers –Laser printers –Inkjet printers (use CMYK color model) –Thermal wax transfer printers –Dye sublimation printers