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Camera Technology Basics Overview Basics of Camera Technology Saugaato Ray Director & CEO SATMAC INFOSYS LTD.

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Presentation on theme: "Camera Technology Basics Overview Basics of Camera Technology Saugaato Ray Director & CEO SATMAC INFOSYS LTD."— Presentation transcript:

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2 Camera Technology Basics Overview Basics of Camera Technology Saugaato Ray Director & CEO SATMAC INFOSYS LTD.

3 Camera Technology Concepts Image acquisition, processing, encoding –Lenses –Raster scanning –CCD technology –Image processing –Video signals Output Image Acquisition ProcessEncoding Light LensOpticalBlockImager GainGamma Color Balance White Clip Enhancement Analog / Digital Output FormatConversion & Digitization

4 Image Acquisition Lenses Optical block Imager

5 Lenses Zoom/Focus Control –Fixed – e.g.- SNC-P1. –Manual => Vari-focal- eg- CS-50P, DF-40P. –Auto Zoom and Focus –eg - SNC-RZ30P.

6 Imager Sensor –CCD / CMOS Scanning –Interlaced / progressive

7 CCD vs. CMOS CCDCMOS Advantage * High sensitivity * High Quality * Low power consumption * High speed read-out * Smear-less * Easiness of consolidating chip * Low Cost Disadvantage * Smear * External pulse for the drive * Larger in size. * More power consumption. * Noisy * Low Image Quality. * Low Sensitivity.

8 CCD Imagers CCDs (Charge Coupled Devices) made their first commercial appearance in a camera in It uses solid-state technology There are three types of CCD imagers viz IT (Interline Transfer), FIT (Frame Interline Transfer) & FT (Frame Transfer) FIT sensors are the most expensive to produce & are primarily used in high end broadcast cameras. Now Sony has IT CCD with technology which give better results as FIT.

9 Miniaturization and Sensitivity Unit cell area [um ] 2 Pixels 1/4Type Diagonal 4.5mm 1/2Type Diagonal 11mm 1/3Type Diagonal 6mm Larger the size of CCD, more is the Sensitivity.

10 The size of an imager greatly determines the overall potential quality of an image. The larger the area of any given type of CCD, the better the image quality. Imager Size The imager size is the diameter of the circle

11 Scanning odd lines Field one even lines Field two Frame All lines Interlaced Scanning --- odd lines and even lines scanned separately

12 PAL Scanning 25 frames per second 2 fields per frame 50 fields per second 625 lines per frame lines per field

13 Processing technology Exposure White Balance Gamma Correction Day / Night DynaView

14 Exposure Exposure is affected by Mechanical Iris Electronic shutter –CCD Iris [auto shutter function] Electronic gain DarkBright AGC Incoming Iris or gain level Mechanical Iris Electronic shutter

15 Electronic Shutter Time Exposure Intensity Shutter Slow >> Fast Exposure time

16 Electronic Gain Gain-upOutput signal level 6 dB2 times 9 dB3 times 12 dB4 times 18 dB8 times 24 dB16 times As the Gain increases, the S/N ratio decreases !!

17 ~ Sample picture ~ 24dB gain up 0dB (no gain up)

18 AGC (Automatic Gain Control) Circuitry that automatically adjusts the electronic amplification of the video signal to compensate for varying levels of scene illumination.

19 White Balance Levels Balanced Levels Unbalanced Combination of R, G & B gives White, properly balanced RGB levels gives perfect white.

20 Picture Sample Before After Properly Balanced White Level..

21 Gamma Correction Light Directed onto Camera Imager Light Directed onto Camera Imager Display System Gamma Display System Gamma Camera Gamma Camera Gamma CRT Brightness CRT Brightness

22 Day/Night Mode B/W mode Color mode Remove IR Cut Filter Sensitivity Improvement technology IR light has high content of heat. During daylight it hampers image of ccd. IR filter comes in place during Daylight, cutting off IR spectrum. At night it is automatically removed to improve sensitivity of CCD.

23 DynaView DynaView = One picture atOne picture at Normal Shutter picture + high speed shutter picture Normal Shutter speed: 1/60 or 1/50 High speed: 1/500 ~ approx 1/8000 Camera show a high light picture with about x8~10 brightness.

24 Technology Definition Minimum Illumination A measure of the least illumination that will produce an image at the highest Gain of the camera with the lens aperture set to full open. –Minimum Illumination specifications will be affected by the lens used. –Because the highest Gain is used, the image quality is affected by lower S/N Ratio.

25 Technology Definition Resolution A measure of the ability to image picture detail. –Vertical Resolution is limited to the number of scan lines that make up the image. This theoretical limit for a PAL Video signal is 483 lines. (525 Lines - 42 lines of the Vertical Interval) –Horizontal Resolution is the number of alternating black and white lines which can be imaged across 75% of the width of the picture. (Assuming PAL Video with a 4:3 Aspect Ratio) –Horizontal resolution increases with size of the CCD and with the number of CCD sensors used in the camera.

26 What is the difference Sensitivity Image Quality Why Larger Imager is good About Lens PAL / NTSC

27 Sensitivity Sensitivity Depends on –Imaging cell size –Day / Night function –Super HAD, Exwave HAD technology –With or Without Color filter –Signal gain-up

28 Sensitivity Sensitivity Depends on –Imaging cell size The bigger imager cell size become, The Higher sensitivity goes.

29 Sensitivity Sensitivity Depends on –Imaging cell size The bigger imager size become, The Higher sensitivity goes. Here is a question….

30 Sensitivity Sensitivity Depends on –Imaging cell size The bigger imager size become, The Higher sensitivity goes. Q. Which has higher sensitivity A. 1/3 inch 30k Pixels B. 1/3 inch 60k Pixels

31 Sensitivity Sensitivity Depends on –Imaging cell size The bigger imager size become, The Higher sensitivity goes. Q. Which has higher sensitivity A. 1/3 inch 30k Pixels B. 1/3 inch 60k Pixels

32 Sensitivity Sensitivity Depends on –Day / Night function Normal Color Imager has IR filter

33 Sensitivity Sensitivity Depends on –Day / Night function Normal Color Imager has IR filter Without IR filter, Tone of color will collapse Imager will be easily affected by heat. ( IR is a heat ray )

34 Sensitivity Sensitivity Depends on –Day / Night function Day / Night function cuts off the IR filter in the night time We can see image in very dark circumstances (Notice : In Night mode, Image goes to B/W)

35 Sensitivity Sensitivity Depends on –Super HAD, Exwave HAD technology One of Imager structure technology

36 Sensitivity Sensitivity Depends on –Super HAD, Exwave HAD technology ( Imager structure ) Super HAD Exwave HAD Super Exwave

37 Sensitivity Sensitivity Depends on –Super HAD, Exwave HAD technology ( Imager structure ) Super HAD –Higher Efficiency Micro lens Array before imager –Good on both Day mode and Night mode Exwave HAD Super Exwave

38 Sensitivity Sensitivity Depends on –Super HAD, Exwave HAD technology ( Imager structure ) Super HAD –Higher Efficiency Micro lens Array before imager –Good on both Day mode and Night mode Exwave HAD –Higher Sensitivity to Infrared –Good on night mode Super Exwave

39 Sensitivity Sensitivity Depends on –Super HAD, Exwave HAD technology ( Imager structure ) Super HAD –Higher Efficiency Micro lens Array before imager –Good on both Day mode and Night mode Exwave HAD –Higher Sensitivity to Infrared –Good with Day / Night function Super Exwave –Much higher sensitivity to Infrared –Better with Day / Night function

40 Comparison of Hyper HAD CCD and Super HAD CCD Sensor Structure On-chip Micro lens of Conventional CCDOn-chip Micro lens of Super HAD CCD Hyper HAD CCD Sensor StructureSuper HAD CCD Sensor Structure

41 Exwave HAD Wave Length [nm] Relative Response The past CCD vs. Exwave HAD Spectral Sensitivity The past CCD Exwave HAD

42 Super Exwave Exwave HAD vs. Super Exwave Exwave HAD Super Exwave

43 Exwave HAD vs. Super Exwave Exwave HAD 0.7lx Super Exwave 0.55lx illumination High Low

44 Sensitivity Sensitivity Depends on –With or Without Color Filter Color Imager = B / W Imager + Color Filter

45 Sensitivity Sensitivity Depends on –With or Without Color Filter Color Imager = B / W Imager + Color Filter Color Imager is just like B/W with Sunglasses

46 Sensitivity Sensitivity Depends on –With or Without Color Filter Color Imager = B / W Imager + Color Filter Color Imager is just like B/W with Sunglasses The reason why color imager has lower sensitivity

47 Sensitivity Sensitivity Depends on –Signal gain-up

48 Sensitivity Sensitivity Depends on –Signal gain-up Some camera has more gain-up capacity.

49 Sensitivity Sensitivity Depends on –Signal gain-up Some camera has more gain-up capacity. ( Gain-up is amplification of signal from imager )

50 Sensitivity Sensitivity Depends on –Signal gain Some camera has more gain-up capacity. ( Gain-up is amplification of signal from imager ) Even though Image may be noisy,we can get image in darker situation.

51 Sensitivity Sensitivity Depends on –Imaging cell size –Day / Night function –Imager structure –With or Without Color filter –DSP gain up

52 Image quality Image quality Depends on –Imaging cell number –With or Without DynaView Technology –With or Without Variable Gamma Curve

53 Image quality Image quality Depends on –Imaging cell number

54 Image quality Image quality Depends on –Imaging cell number The more imaging cell become, the higher image resolution goes.

55 Image quality Image quality Depends on –Imaging cell number The more imaging cell become, the higher image resolution goes. (Notice : Higher resolution Imager have less sensitivity.)

56 Image quality Image quality Depends on –With or Without DynaView Technology

57 Image quality Image quality Depends on –With or Without DynaView Technology prevents dark area from going to absolute black, While preventing bright area from going to absolute white.

58 Image quality Image quality Depends on –With or Without DynaView Technology prevents dark area from going to absolute black, While preventing bright area from going to absolute white. By taking picture twice in one frame period.

59 Image quality Image quality Depends on –With or Without DynaView Technology prevents dark area from going to absolute black, While preventing bright area from going to absolute white. By taking picture twice in one frame period. 1 st. At slower shutter speed for dark area to be bright.

60 Image quality Image quality Depends on –With or Without DynaView Technology prevents dark area from going to absolute black, While preventing bright area from going to absolute white. By taking picture twice in one frame period. 1 st. At slower shutter speed for dark area to be bright. 2 nd.At faster shutter speed for bright area to be dark.

61 Image quality Image quality Depends on –With or Without Variable Gamma Curve

62 Image quality Image quality Depends on –With or Without Variable Gamma Curve Enhancing Vividness of Image

63 Image quality Image quality Depends on –With or Without Variable Gamma Curve Enhancing Vividness of Image –Taking brightest pixel of image to absolute white –Taking darkest pixel of image to absolute black

64 Image quality Image quality Depends on –With or Without Variable Gamma Curve Enhancing Vividness of Image –Taking brightest pixel of image to absolute white –Taking darkest pixel of image to absolute black –Taking reddest pixel of image to absolute red –Enhancing solidity of object.

65 Why Larger Imager is good To achieve higher sensitivity, The imaging cell must be larger. To achieve higher resolution More imaging cell is needed.

66 Why Larger Imager is good To achieve higher sensitivity, The imaging cell must be larger. To achieve higher resolution More imaging cell is needed. What would you do, if you want both sensitivity and resolution?

67 Why Larger Imager is good To achieve higher sensitivity, the imaging cell must be larger. To achieve higher resolution, more imaging cell is needed. What would you do, if you want both sensitivity and resolution? Larger imager can achieve both of these.

68 Why Larger Imager is good To achieve higher sensitivity, the imaging cell must be larger. To achieve higher resolution, more imaging cell is needed. What would you do, if you want both sensitivity and resolution? Larger imager can achieve both of these. This is why larger imager is good.

69 Why Larger Imager is good To achieve higher sensitivity, the imaging cell must be larger. To achieve higher resolution, more imaging cell is needed. What would you do, if you want both sensitivity and resolution? Larger imager can achieve both sensitivity and resolution, even though Larger imager is more expensive.

70 Why Larger Imager is good To achieve higher sensitivity, the imaging cell must be larger. To achieve higher resolution, more imaging cell is needed. What would you do, if you want both sensitivity and resolution? Lager imager can achieve both sensitivity and resolution, even though Lager imager is more expensive. 1/3 > 1/4 > 1/6

71 About Lens Brightness Image Angle Iris Servo

72 About Lens Brightness The smaller F value goes….

73 About Lens Brightness The smaller F value goes…. the brighter the lens become.

74 About Lens Brightness The smaller F value goes…. the brighter the bigger the lens become.

75 About Lens Brightness The smaller F value goes…. the brighter the bigger the more expensive the lens become.

76 About Lens Image Angle The smaller f value goes….

77 About Lens Image Angle The smaller f value goes…. the wider image angle become.

78 About Lens Image Angle The smaller f value goes…. the wider image angle become. Wide Angle Lens..

79 About Lens Image Angle The larger the f value goes….

80 About Lens Image Angle The larger the f value goes…. the narrower image angle become.

81 About Lens Image Angle The larger the f value goes…. the narrower image angle become. Tele-Photo Lens..

82 About Lens Image Angle Vari-focal Lens can Change Image angle like zoom lens.

83 About Lens Image Angle Vari-focal Lens can Change Image angle like zoom lens. ( With Vari-focal Lens, Image will go out of focus, after changing Image Angle, while image dont go out of focus with ordinary zoom lens. Vari-focal Lens is cheaper than ordinary zoom lenses)

84 End.


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