1. 1 IMAGE ACQUSITION

2. 2 VIDEO

3. 3 TRANSMISSION OF IMAGES/VIDEO

4. 4 SCANNING

5. 5 25 lines 250 lines 500 lines Europe: 625 lines, USA: 525 lines RESOLUTION

6. 6 Europe: 50Hz USA: 60 Hz VISUAL SENSITIVITY TO FLICKER

7. 7 INTERLACED SCAN

8. 8 Red Color(RGB) Green Blue C = x R + y G + z B Luminance, Y = 0.3 R + 0.59 G + 0.11 B Color Difference signals: (R-Y), (G-Y), (B-Y) (G-Y)= -0.51(R-Y)-0.19 (B-Y) COLOR

9. 9 x y (0,0) [or (1,1) depending on index format] Image Space: Digital Images: Sampling Quantization DIGITAL IMAGES

10. 10 SAMPLING: SPATIAL RESOLUTION 256x256 pixels 128x128 pixels 64x64 pixels 32x32 pixels

11. 11 QUANTIZATION: BIT DEPTH 8 bits: 256 levels4 bits: 16 Levels1 bit: 2 levels

12. 12 DIGITAL TV STANDARD ITU-R BT.601 Digital TV standard: 13.5 MHz sampling frequency, 720 samples/line (525 lines/60 Hz & 625 lines/50Hz) Luminance (Y) = 0.3 R + 0.59 G + 0.11 B (8 bits) Color Differences: (B-Y) = -0.3 R - 0.59 G + 0.89 B (R-Y) = 0.7 R - 0.59 G - 0.11 B Chrominance: C b =0.56(B-Y)= - 0.17 R - 0.33 G + 0.5 B (8 bits) C r =0.71(R-Y)= 0.5 R - 0.42 G - 0.08 B (8 bits)

13. 13 SAMPLING FORMATS / 1 4:2:2 systems (D-1, D-5, DigiBeta, BetaSX, Digital-S, DVCPRO 50) Each line: 720 Y 360 C b & C r

14. 14 SAMPLING FORMATS / 2 4:1:1 systems (NTSC DV & DVCAM, DVCPRO ) Each line: 720 Y 180 C b.& C r

15. 15 SAMPLING FORMATS / 3 4:2:0 systems (PAL DV, DVD, MPEG-2 main profile) Each Line: 720 Y 360 C b or C r

16. 16 ALTERNATIVE DIGITAL VIDEO STANDARDS Videoconferencing Quality - CIF Common Interchange Format (CIF), (ITU-TS H.261) Frame size (4:1:1 sub-sampling): 352 x 288 for luminance (Y) 176 x 144 for chrominances (U, V) Data rate = 36 Mbps (Uncompressed). Videoconferencing Quality - QCIF Quarter-Common Interchange Format (QCIF) Frame size: 176 x 144 for luminance (Y) 176 x 144 for chrominances (U, V) Data rate = 18 Mbps (Uncompressed).

17. 17 ALTERNATIVE DIGITAL VIDEO STANDARDS Videoconferencing Quality - Super-CIF Super-Common Interchange Format (Super-CIF) Frame size (4:1:1 sub-sampling): 704 x 576 for luminance (Y) 352 x 288 for chrominances (U, V) Data rate = 146 Mbps (Uncompressed). VCR Quality - SIF Standard Interchange Format (Defined in MPEG-1) Frame size (4:1:1 sub-sampling): 352 x 240 (NTSC) or 352 x 288 (PAL/SECAM) for luminance (Y) 176 x 120 or 144 for chrominances (U, V)

18. 18 IMAGE STRUCTURE header image data format Formats: gif, jpeg, pgm, pbm, tiff...

19. 19 Sample Image Format P2 # PGM, grayscale, ASCII 7 255 217 217 217 217 217 217 217 217 217 217 30 217 217 217 217 217 26 26 26 217 217 217 217 217 26 216 217 217 217 217 217 215 216 217 217 217 217 217 216 216 217 217

20. 20 SAMPLE IMAGE FORMAT P5 # PGM, grayscale, Binary 7 255 ÙÙÙÙÙÙÙÙÙÙÙÙÙÙÙÙÙ ‑ ÙÙÙÙÙÙÙÙÙÙØÙÙÙ ÙÙ×ØÙÙÙÙÙØØÙÙ

21. 21 SIMPLE IMAGE PROCESSING: FLIP

22. 22 SIMPLE IMAGE PROCESSING: MIRROR

23. 23 SIMPLE IMAGE PROCESSING: SHIFT 30 pix

24. 24 SMPLE IMAGE PROCESSING: RESIZE 256x256 512x512

25. 25 SIMPLE IMAGE PROCESSING: CROP

26. 26 SIMPLE IMAGE PROCESSING: BRIGHTNESS CHANGE (a) Sample dark image (b) Pixel values increased (8 bit) by 100 if b>0 brightness increases if b<0 brightness decreases

27. 27 SIMPLE IMAGE PROCESSING: CONTRAST CHANGE (a) Sample dark image (b) Pixel values multiplied by 2 if a>1 contrast increases if a<1 contrast decreases

28. 28 QUESTION: EFFECT OF BRIGHTNESS AND CONTRAST CHANGE WHAT HAPPENS TO THE IMAGE a)MEAN b)VARIANCE AFTER BRIGHTNESS/CONTRAST CHANGE ?

29. 29 SIMPLE IMAGE PROCESSING:THRESHOLDING g g f 255 70 f 255 70

30. 30 EXAMPLE: THRESHOLDING TO DETECT CHANGES _ Th.

31. 31 EXAMPLE IMAGE ENHANCEMENT f 255 50 100 g

32. 32 IMAGE ENHANCEMENT: NONLINEAR MAPPING f 255 50 100 g

33. 33 IMAGE HİSTOGRAM Histogram: Shows the number (frequency) of pixels for each pixel level. [h(i)]

34. 34 HİSTOGRAM EQUALIZATION a

35. 35 CONVOLUTION -1 0 1 * -2 0 2 -1 0 1

36. 36 CONVOLUTION COMPUTATION -1 0 1 72 53 60 -2 0 2 * 76 56 65 -1 0 1 88 78 82 k f

37. 37 SEPARABLE KERNELS In case of separable kernels, the computational load drop to About 10 %. 1 *-1 0 1 * 2 1

38. 38 CORRELATION Correlation surface:

39. 39 LOW-PASS FILTERING 1 1 1 1 1 1 1 1

40. 40 HIGH-PASS FILTERING -1 -1 -1 -1 8 -1 -1 -1 -1 * Offset=128 +128

41. 41 SIMPLE EDGE DETECTORS Prewitt kernels: Sobel kernels: -1 0 1 -1 -1 -1 0 0 0 1 1 1 -1 0 1 -2 0 2 -1 0 1 -1 -2 -1 0 0 0 1 2 1 (Offset=128)

42. 42 EDGE DETECTION EXAMPLE Edge detection kernel only LPF + Edge Detection kernel

43. 43 NONLINEAR FILTERING EXAMPLE: MEDİAN The median filter sorts the pixel values within the region of interest and takes the median value as output. 64 65 76 56 68 61 34 55 68 34 55 56 61 64 65 68 68 76 3x3: