# Lecture 2: Image Formation and Cameras

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 #1 Lecture 2: Image Formation and Cameras Saad J Bedros

2 Last Lecture #2 What is Computer vision: deals with the formation, analysis and interpretation of Images Evolving field in Artificial Intelligence Enabler in Robotics as a smart sensor for better decision making.

3 Outline for this Lecture #3 Image Formation Cameras and Lenses Human Visual System Digital Cameras Digital Image representation

4

5 The Electromagnetic Spectrum Radio Waves - communication Microwaves - used to cook Infrared - heat waves Visible Light - detected by your eyes Ultraviolet - causes sunburns X-rays - penetrates tissue Gamma Rays - most energetic

6 The Multi-Wavelength Sun X-Ray UV Visible Infrared Composite Radio

7 Visible Spectrum #7 Light waves extend in wavelength from about 400 to 700 nanometers

8 #8 Image Formation

9 Quantum Theory of Light Newton proposed that light is a stream of particles traveling in a straight line. Each particle is called a quantum and each quantum of light is a photon. Thus the intensity of light is measured in number of photons. the visible spectrum is from 380 nm (violet) to 760 nm (red) refraction occurs when light enters a different medium causing the velocity of the light to change, this change bends the direction of the light Short wavelengths (violet) of light are refracted more than longer wavelengths (red). This is why a spectrum is formed from white light passing through a prism and it also causes the problem of chromatic aberration #9

10 How do we Capture an Image? #10

11 Image formation There are two parts to the image formation process: (1)The geometry, which determines where in the image plane the projection of a point in the scene will be located. (2) The physics of light, which determines the brightness of a point in the image plane. Simple model: f(x,y) = i(x,y) r(x,y) i: illumination, r: reflectance

12 Image formation Object Film Let s design a camera Idea 1: put a piece of film in front of an object Do we get a reasonable image? Blurring

13 Pinhole camera Object Barrier Film Add a barrier to block off most of the rays This reduces blurring The opening known as the aperture How does this transform the image?

14 Image Formation: Simple Model Digital Camera Film The Eye

15 History of Imaging: Camera Obscura History 1544 Device that led to Photography and the Camera "When images of illuminated objects... penetrate through a small hole into a very dark room... you will see [on the opposite wall] these objects in their proper form and color, reduced in size... in a reversed position, owing to the intersection of the rays". Leonardo da Vinci Slide credit: David Jacobs

16 Camera Obscura The first camera How does the aperture size affect the image? How does the size of the box affect the image?

17 Pinhole camera model The simplest device to form an image of a 3D scene on a 2D surface. Rays of light pass through a "pinhole" and form an inverted image of the object on the image plane. perspective projection: center of projection (X,Y,Z) (x,y) x = fx Z y = fy Z f: focal length, distance from pinhole to image plane

18 Pinhole and the Perspective Projection (x,y) Is an image being formed on the screen? screen image plane scene y YES! But, not a clear one. r = ( x, y, z) optical axis effective focal length, f z x pinhole r' = ( x', y', f ') r ' = f ' r z x' f ' = x z y' f ' = y z

19 What is the effect of aperture size? Large aperture: light from the source spreads across the image (i.e., not properly focused), making it blurry! Small aperture: reduces blurring but (i) it limits the amount of light entering the camera and (ii) causes light diffraction.

20 Shrinking the aperture #20 Why not make the aperture as small as possible? Less light gets through

21 Shrinking more the aperture What happens if we keep decreasing aperture size? When light passes through a small hole, it does not travel in a straight line and is scattered in many directions (i.e., diffraction)

22 Shrinking the aperture #22 Pinhole too big - many directions are averaged, blurring the image Pinhole too small - diffraction effects blur the image Generally, pinhole cameras are dark, because a very small set of rays from a particular point hits the screen.

23 Problems with Pinholes Pinhole size (aperture) must be very small to obtain a clear image. However, as pinhole size is made smaller, less light is received by image plane. If pinhole is comparable to wavelength of incoming light, DIFFRACTION effects blur the image! Sharpest image is obtained when: pinhole diameter d = 2 f ' λ Example: If f = 50mm, λ = 600nm (red), d = 0.36mm

24 Traditional Photography A chemical process, little changed from 1826 Taken in France on a pewter plate with 8-hour exposure The world's first photograph 24

25 History of Imaging: Adding a Lens Lens Based Camera Obscura, 1568

26 First Camera Design #26

27 The Reason for Lenses #27 Gather more light from each scene point

28 Adding a lens Pinhole replaced by a Lens Lens redirect light rays emanating from the object Lens improve image quality, leading to sharper images.

29 Lenses #29 F optical center (Center Of Projection) focal point A lens focuses parallel rays onto a single focal point focal point at a distance f beyond the plane of the lens f is a function of the shape and index of refraction of the lens Aperture of diameter D restricts the range of rays aperture may be on either side of the lens Lenses are typically spherical (easier to produce)

30 Properties of thin lens (i.e., ideal lens) focal point f Light rays passing through the center are not deviated. Light rays passing through a point far away from the center are deviated more.

31 Properties of thin lens (i.e., ideal lens) focal point f All parallel rays converge to a single point. When rays are perpendicular to the lens, it is called focal point.

32 Properties of thin lens focal point f The plane parallel to the lens at the focal point is called the focal plane. The distance between the lens and the focal plane is called the focal length (i.e., f) of the lens.

33 Thin lenses Object Lens Film Focal point Thin lens equation: Not quite right Any object point satisfying this equation is in focus What is the shape of the focus region? How can we change the focus region? Thin lens applet: (by Fu-Kwun Hwang )

34 Thin lens equation Assume an object at distance u from the lens plane: v f u object image

35 Thin lens equation (cont d) Using similar triangles: y v f image u y y /y = v/u

36 Thin lens equation (cont d) Using similar triangles: y v f image u y y /y = (v-f)/f

37 Thin lens equation (cont d) Combining the equations: v f u image u + v = f

38 Lens Aperture #38

39 Adding a lens Object Lens Film A lens focuses light onto the film There is a specific distance at which objects are in focus other points project to a circle of confusion in the image Changing the shape of the lens changes this distance circle of confusion

40 depth of field The size of blur circle is proportional to aperture size.

41 Controlling depth of field Changing the aperture size affects depth of field A smaller aperture increases the range in which the object is approximately in focus But small aperture reduces amount of light need to increase exposure

42 Depth of Field Changing the aperture of a camera also changes the amount of the image that is in focus this amount is called the depth of field

43 depth of field trade off Changing aperture size (controlled by diaphragm) affects depth of field. A smaller aperture increases the range in which an object is approximately in focus (but need to increase exposure time). A larger aperture decreases the depth of field (but need to decrease exposure time).

44 Depth of field trade off Aperture Film f / 5.6 Changing the aperture size affects depth of field f / 32 A smaller aperture increases the range in which the object is approximately in focus

45 Depth of Field The range of depths over which the world is approximately sharp (i.e., in focus).

46 Another Example Large aperture = small DOF

47 Varying aperture size Large aperture = small DOF Small aperture = large DOF DOF is Depth of Field

48 Aperture Small Apertures (e.g. f11, f16, f22) only let a small amount of light through Large Apertures (e.g. f4, f5.6, f8) let through a lot of light So for a sunny day you might need to use a small aperture to get the correct exposure

49 Thin lens assumption The thin lens assumption assumes the lens has no thickness, but this isn t true Object Lens Film Focal point By adding more elements to the lens, the distance at which a scene is in focus can be made roughly planar.

50 Field of View (Zoom) The cone of viewing directions of the camera. Inversely proportional to focal length. f f

51 Field of View (Zoom)

52 Lens Flaws: Chromatic Aberration Lens has different refractive indices for different wavelengths. Could cause color fringing: i.e., lens cannot focus all the colors at the same point.

53 Chromatic Aberration - Example

54 Lens Flaws: Radial Distortion Straight lines become distorted as we move further away from the center of the image. Deviations are most noticeable for rays that pass through the edge of the lens.

55 Lens Flaws: Radial Distortion No distortion Pin cushion Barrel

56 Lens Flaws: Tangential Distortion Lens is not exactly parallel to the imaging plane!

57 Now the test! Under or over exposure?

58 Now the test! Which is the largest aperture?

59 Now the test! Under, or over exposed?

60 Now the test! Small or large aperture?

61 Human Eye #62 Cameras are a Copy of the Human Eye!

62 Human Eye vs. the Camera We make cameras that act similar to the human eye

63 Image formation in the eye 64 Light receptor Brain radiant energy electrical impulses

64 Human Eye The eye has an iris like a camera Focusing is done by changing shape of lens Retina contains cones (mostly used) and rods (for low light) The fovea is small region of high resolution containing mostly cones Optic nerve: 1 million flexible fibers Slide credit: David Jacobs

65 Human Eye: Pupil Hole or opening where light enters Or, the diameter of that hole or opening Pupil of the human eye Bright light: 1.5 mm diameter Average light: 3-4 mm diameter Dim light: 8 mm diameter Camera Wider aperture admits more light Though leads to blurriness in the objects away from point of focus 66

66 Human Eye : Lens Focusing is achieved by varying the shape of the lens (i.e., flattening of thickening).

67 Human Eye: Retina Retina contains light sensitive cells that convert light energy into electrical impulses that travel through nerves to the brain. Brain interprets the electrical signals to form images.

68 Retina up-close Light

69 Two types of light-sensitive receptors Cones cone-shaped less sensitive operate in high light color vision Rods rod-shaped highly sensitive operate at night gray-scale vision Stephen E. Palmer, 2002

70 Rod / Cone sensitivity ME5286 The Lecture famous 2 (Theory) sock-matching problem

71 Human Eye - Color Three different types of cones; each type has a special pigment that is sensitive to wavelengths of light in a certain range: Short (S) corresponds to blue Medium (M) corresponds to green Long (L) corresponds to red Ratio of L to M to S cones: approx. 10:5:1 Almost no S cones in the center of the fovea RELATIVE ABSORBANCE (%) S nm. M L WAVELENGTH (nm.)

72 Visual Cortex #73

73 Visual Perception #74 Modern view is that visual transformation is a creative process Vision transforms light stimuli on the retina into mental constructs of a stable 3D world Visual perception is a 3D perception of the world that is invariant to a wide range of changes in illumination, size, shape, and brightness of the image

74 Digital Image Formation

75 First digitally scanned photograph 1957, 176x176 pixels

76 Digital cameras A digital camera replaces film with a sensor array. Each cell in the array is light-sensitive diode that converts photons to electrons Two common types Charge Coupled Device (CCD) Complementary metal oxide semiconductor (CMOS)

77 What is a digital image? 8 bits/pixel 0 255

78 Spatial Sampling #79

79 Quantization #80

80 Image Acquisition Pipeline Lens Shutter scene radiance sensor irradiance sensor exposure 2 (W/sr/m ) t CCD ADC Remapping analog voltages digital values pixel values

81 Digital Camera: Properties Focus Shifts the depth that is in focus. Focal length Adjusts the zoom, i.e., wide angle or telephoto lens. Aperture Adjusts the depth of field and amount of light let into the sensor. Exposure time How long an image is exposed. The longer an image is exposed the more light, but could result in motion blur. ISO Adjusts the sensitivity of the film. Basically a gain function for digital cameras. Increasing ISO also increases noise.

82 Camera exposure ISO number Sensitivity of the film or the sensor Can go as high as 1,600 and 3,200 Shutter speed How fast the shutter is opened and closed f/stop The size of aperture 1.0 ~ 32 83

83 Illumination #84 1 Lux = 1 Lumen/m 2 = ft-candles Office = 100-1,000 Lux Sunlight = 50, ,000 Lux Cloudy day = 1,1000 Lux Twilight = 1-10 Lux Full moon = Lux Night sky =

84 Exposure #85

85 Exposure Time #86

86 Aperture & Shutter control Exposure #87

87 Aperture vs. Shutter #88

88 Long Exposure Real world 10-6 High dynamic range 10 6 Picture to 255

89 Short Exposure Real world 10-6 High dynamic range 10 6 Picture to 255

90 Varying Exposure

91 Image file formats Many image formats adhere to the simple model shown below (line by line, no breaks between lines). The header contains at least the width and height of the image. Most headers begin with a signature or magic number (i.e., a short sequence of bytes for identifying the file format)

92 Common image file formats GIF (Graphic Interchange Format) - PNG (Portable Network Graphics) JPEG (Joint Photographic Experts Group) TIFF (Tagged Image File Format) PGM (Portable Gray Map) FITS (Flexible Image Transport System)

93 PBM/PGM/PPM format A popular format for grayscale images (8 bits/pixel) Closely-related formats are: PBM (Portable Bitmap), for binary images (1 bit/pixel) PPM (Portable Pixelmap), for color images (24 bits/pixel)» ASCII or binary (raw) storage ASCI Binary

94 Chromatic Aberration #95

95 Spherical Aberration #96

### IMAGE FORMATION. Light source properties. Sensor characteristics Surface. Surface reflectance properties. Optics

IMAGE FORMATION Light source properties Sensor characteristics Surface Exposure shape Optics Surface reflectance properties ANALOG IMAGES An image can be understood as a 2D light intensity function f(x,y)

### Basic principles of photography. David Capel 346B IST

Basic principles of photography David Capel 346B IST Latin Camera Obscura = Dark Room Light passing through a small hole produces an inverted image on the opposite wall Safely observing the solar eclipse

### Image Formation and Capture. Acknowledgment: some figures by B. Curless, E. Hecht, W.J. Smith, B.K.P. Horn, and A. Theuwissen

Image Formation and Capture Acknowledgment: some figures by B. Curless, E. Hecht, W.J. Smith, B.K.P. Horn, and A. Theuwissen Image Formation and Capture Real world Optics Sensor Devices Sources of Error

### Visual perception basics. Image aquisition system. IE PŁ P. Strumiłło

Visual perception basics Image aquisition system Light perception by humans Humans perceive approx. 90% of information about the environment by means of visual system. Efficiency of the human visual system

### Digital Image Processing COSC 6380/4393

Digital Image Processing COSC 6380/4393 Lecture 2 Aug 24 th, 2017 Slides from Dr. Shishir K Shah, Rajesh Rao and Frank (Qingzhong) Liu 1 Instructor TA Digital Image Processing COSC 6380/4393 Pranav Mantini

### Cameras. Digital Visual Effects Yung-Yu Chuang. with slides by Fredo Durand, Brian Curless, Steve Seitz and Alexei Efros

Cameras Digital Visual Effects Yung-Yu Chuang with slides by Fredo Durand, Brian Curless, Steve Seitz and Alexei Efros Announcements Do subscribe the mailing list Check out scribes from past years Camera

### CS 443: Imaging and Multimedia Cameras and Lenses

CS 443: Imaging and Multimedia Cameras and Lenses Spring 2008 Ahmed Elgammal Dept of Computer Science Rutgers University Outlines Cameras and lenses! 1 They are formed by the projection of 3D objects.

### Image Acquisition and Representation. Camera. CCD Camera. Image Acquisition Hardware

Image Acquisition and Representation Camera Slide 1 how digital images are produced how digital images are represented Slide 3 First photograph was due to Niepce of France in 1827. Basic abstraction is

### Digital Image Processing

Digital Image Processing Lecture # 3 Digital Image Fundamentals ALI JAVED Lecturer SOFTWARE ENGINEERING DEPARTMENT U.E.T TAXILA Email:: ali.javed@uettaxila.edu.pk Office Room #:: 7 Presentation Outline

### Cameras. Digital Visual Effects, Spring 2008 Yung-Yu Chuang 2008/2/26. with slides by Fredo Durand, Brian Curless, Steve Seitz and Alexei Efros

Cameras Digital Visual Effects, Spring 2008 Yung-Yu Chuang 2008/2/26 with slides by Fredo Durand, Brian Curless, Steve Seitz and Alexei Efros Camera trial #1 scene film Put a piece of film in front of

### Image Formation: Camera Model

Image Formation: Camera Model Ruigang Yang COMP 684 Fall 2005, CS684-IBMR Outline Camera Models Pinhole Perspective Projection Affine Projection Camera with Lenses Digital Image Formation The Human Eye

### Vision. The eye. Image formation. Eye defects & corrective lenses. Visual acuity. Colour vision. Lecture 3.5

Lecture 3.5 Vision The eye Image formation Eye defects & corrective lenses Visual acuity Colour vision Vision http://www.wired.com/wiredscience/2009/04/schizoillusion/ Perception of light--- eye-brain

### Chapter 2: Digital Image Fundamentals. Digital image processing is based on. Mathematical and probabilistic models Human intuition and analysis

Chapter 2: Digital Image Fundamentals Digital image processing is based on Mathematical and probabilistic models Human intuition and analysis 2.1 Visual Perception How images are formed in the eye? Eye

### Section 1: Sound. Sound and Light Section 1

Sound and Light Section 1 Section 1: Sound Preview Key Ideas Bellringer Properties of Sound Sound Intensity and Decibel Level Musical Instruments Hearing and the Ear The Ear Ultrasound and Sonar Sound

### Lecture 7: Camera Models

Lecture 7: Camera Models Professor Stanford Vision Lab 1 What we will learn toda? Pinhole cameras Cameras & lenses The geometr of pinhole cameras Reading: [FP]Chapters 1 3 [HZ] Chapter 6 2 What we will

### Image and Multidimensional Signal Processing

Image and Multidimensional Signal Processing Professor William Hoff Dept of Electrical Engineering &Computer Science http://inside.mines.edu/~whoff/ Digital Image Fundamentals 2 Digital Image Fundamentals

### Sensors and Sensing Cameras and Camera Calibration

Sensors and Sensing Cameras and Camera Calibration Todor Stoyanov Mobile Robotics and Olfaction Lab Center for Applied Autonomous Sensor Systems Örebro University, Sweden todor.stoyanov@oru.se 20.11.2014

### INTRODUCTION THIN LENSES. Introduction. given by the paraxial refraction equation derived last lecture: Thin lenses (19.1) = 1. Double-lens systems

Chapter 9 OPTICAL INSTRUMENTS Introduction Thin lenses Double-lens systems Aberrations Camera Human eye Compound microscope Summary INTRODUCTION Knowledge of geometrical optics, diffraction and interference,

### A CAMERA IS A LIGHT TIGHT BOX

HOW CAMERAS WORK A CAMERA IS A LIGHT TIGHT BOX Pinhole Principle All contemporary cameras have the same basic features A light-tight box to hold the camera parts and recording material A viewing system

### Chapter 29/30. Wave Fronts and Rays. Refraction of Sound. Dispersion in a Prism. Index of Refraction. Refraction and Lenses

Chapter 29/30 Refraction and Lenses Refraction Refraction the bending of waves as they pass from one medium into another. Caused by a change in the average speed of light. Analogy A car that drives off

### Image acquisition. In both cases, the digital sensing element is one of the following: Line array Area array. Single sensor

Image acquisition Digital images are acquired by direct digital acquisition (digital still/video cameras), or scanning material acquired as analog signals (slides, photographs, etc.). In both cases, the

### Lecture Outline Chapter 27. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc.

Lecture Outline Chapter 27 Physics, 4 th Edition James S. Walker Chapter 27 Optical Instruments Units of Chapter 27 The Human Eye and the Camera Lenses in Combination and Corrective Optics The Magnifying

### Chapter 16 Light Waves and Color

Chapter 16 Light Waves and Color Lecture PowerPoint Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. What causes color? What causes reflection? What causes color?

### Cameras and Sensors. Today. Today. It receives light from all directions. BIL721: Computational Photography! Spring 2015, Lecture 2!

!! Cameras and Sensors Today Pinhole camera! Lenses! Exposure! Sensors! photo by Abelardo Morell BIL721: Computational Photography! Spring 2015, Lecture 2! Aykut Erdem! Hacettepe University! Computer Vision

### Astronomical Cameras

Astronomical Cameras I. The Pinhole Camera Pinhole Camera (or Camera Obscura) Whenever light passes through a small hole or aperture it creates an image opposite the hole This is an effect wherever apertures

### Image Formation. Light from distant things. Geometrical optics. Pinhole camera. Chapter 36

Light from distant things Chapter 36 We learn about a distant thing from the light it generates or redirects. The lenses in our eyes create images of objects our brains can process. This chapter concerns

### Capturing Light in man and machine

Capturing Light in man and machine CS194: Image Manipulation & Computational Photography Alexei Efros, UC Berkeley, Fall 2014 Etymology PHOTOGRAPHY light drawing / writing Image Formation Digital Camera

### Refraction of Light. Refraction of Light

1 Refraction of Light Activity: Disappearing coin Place an empty cup on the table and drop a penny in it. Look down into the cup so that you can see the coin. Move back away from the cup slowly until the

### Photography (cont d)

Lecture 13 Ch. 4 Photography continued Ch. 5 The Eye Feb. 23, 2010 Exams will be back on Feb. 25 Homework 5 is due Feb. 25 Read all of Ch. 5. on The Eye. 1 Photography (cont d) Polarizing and haze filters

### Optics B. Science Olympiad North Regional Tournament at the University of Florida DO NOT WRITE ON THIS BOOKLET. THIS IS AN TEST SET.

Optics B Science Olympiad North Regional Tournament at the University of Florida 1 DO NOT WRITE ON THIS BOOKLET. THIS IS AN TEST SET. Part I: General Body Knowledge Questions 2 1) (3 PTS) For much of the

### Reflectors vs. Refractors

1 Telescope Types - Telescopes collect and concentrate light (which can then be magnified, dispersed as a spectrum, etc). - In the end it is the collecting area that counts. - There are two primary telescope

### Intorduction to light sources, pinhole cameras, and lenses

Intorduction to light sources, pinhole cameras, and lenses Erik G. Learned-Miller Department of Computer Science University of Massachusetts, Amherst Amherst, MA 01003 October 26, 2011 Abstract 1 1 Analyzing

### ME 6406 MACHINE VISION. Georgia Institute of Technology

ME 6406 MACHINE VISION Georgia Institute of Technology Class Information Instructor Professor Kok-Meng Lee MARC 474 Office hours: Tues/Thurs 1:00-2:00 pm kokmeng.lee@me.gatech.edu (404)-894-7402 Class

### Human Retina. Sharp Spot: Fovea Blind Spot: Optic Nerve

I am Watching YOU!! Human Retina Sharp Spot: Fovea Blind Spot: Optic Nerve Human Vision Optical Antennae: Rods & Cones Rods: Intensity Cones: Color Energy of Light 6 10 ev 10 ev 4 1 2eV 40eV KeV MeV Energy

### FOR 353: Air Photo Interpretation and Photogrammetry. Lecture 2. Electromagnetic Energy/Camera and Film characteristics

FOR 353: Air Photo Interpretation and Photogrammetry Lecture 2 Electromagnetic Energy/Camera and Film characteristics Lecture Outline Electromagnetic Radiation Theory Digital vs. Analog (i.e. film ) Systems

### Physics 1230 Homework 8 Due Friday June 24, 2016

At this point, you know lots about mirrors and lenses and can predict how they interact with light from objects to form images for observers. In the next part of the course, we consider applications of

### Instructional Resources/Materials: Light vocabulary cards printed (class set) Enough for each student (See card sort below)

Grade Level/Course: Grade 7 Life Science Lesson/Unit Plan Name: Light Card Sort Rationale/Lesson Abstract: Light vocabulary building, students identify and share vocabulary meaning. Timeframe: 10 to 20

### Chapter 9: Light, Colour and Radiant Energy. Passed a beam of white light through a prism.

Chapter 9: Light, Colour and Radiant Energy Where is the colour in sunlight? In the 17 th century (1600 s), Sir Isaac Newton conducted a famous experiment. Passed a beam of white light through a prism.

### Lecture PowerPoint. Chapter 25 Physics: Principles with Applications, 6 th edition Giancoli

Lecture PowerPoint Chapter 25 Physics: Principles with Applications, 6 th edition Giancoli 2005 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the

### Chapter: Sound and Light

Table of Contents Chapter: Sound and Light Section 1: Sound Section 2: Reflection and Refraction of Light Section 3: Mirrors, Lenses, and the Eye Section 4: Light and Color 1 Sound Sound When an object

### Chapter 23. Mirrors and Lenses

Chapter 23 Mirrors and Lenses Notation for Mirrors and Lenses The object distance is the distance from the object to the mirror or lens Denoted by p The image distance is the distance from the image to

### Εισαγωγική στην Οπτική Απεικόνιση

Εισαγωγική στην Οπτική Απεικόνιση Δημήτριος Τζεράνης, Ph.D. Εμβιομηχανική και Βιοϊατρική Τεχνολογία Τμήμα Μηχανολόγων Μηχανικών Ε.Μ.Π. Χειμερινό Εξάμηνο 2015 Light: A type of EM Radiation EM radiation:

### Person s Optics Test KEY SSSS

Person s Optics Test KEY SSSS 2017-18 Competitors Names: School Name: All questions are worth one point unless otherwise stated. Show ALL WORK or you may not receive credit. Include correct units whenever

### Computational Photography and Video. Prof. Marc Pollefeys

Computational Photography and Video Prof. Marc Pollefeys Today s schedule Introduction of Computational Photography Course facts Syllabus Digital Photography What is computational photography Convergence

### Notes from Lens Lecture with Graham Reed

Notes from Lens Lecture with Graham Reed Light is refracted when in travels between different substances, air to glass for example. Light of different wave lengths are refracted by different amounts. Wave

### INTRODUCTION TO CCD IMAGING

ASTR 1030 Astronomy Lab 85 Intro to CCD Imaging INTRODUCTION TO CCD IMAGING SYNOPSIS: In this lab we will learn about some of the advantages of CCD cameras for use in astronomy and how to process an image.

### Lecture 6 6 Color, Waves, and Dispersion Reading Assignment: Read Kipnis Chapter 7 Colors, Section I, II, III 6.1 Overview and History

Lecture 6 6 Color, Waves, and Dispersion Reading Assignment: Read Kipnis Chapter 7 Colors, Section I, II, III 6.1 Overview and History In Lecture 5 we discussed the two different ways of talking about

### IMAGE SENSOR SOLUTIONS. KAC-96-1/5" Lens Kit. KODAK KAC-96-1/5" Lens Kit. for use with the KODAK CMOS Image Sensors. November 2004 Revision 2

KODAK for use with the KODAK CMOS Image Sensors November 2004 Revision 2 1.1 Introduction Choosing the right lens is a critical aspect of designing an imaging system. Typically the trade off between image

### Refraction, Lenses, and Prisms

CHAPTER 16 14 SECTION Sound and Light Refraction, Lenses, and Prisms KEY IDEAS As you read this section, keep these questions in mind: What happens to light when it passes from one medium to another? How

### Light and Applications of Optics

UNIT 4 Light and Applications of Optics Topic 4.1: What is light and how is it produced? Topic 4.6: What are lenses and what are some of their applications? Topic 4.2 : How does light interact with objects

### OFFSET AND NOISE COMPENSATION

OFFSET AND NOISE COMPENSATION AO 10V 8.1 Offset and fixed pattern noise reduction Offset variation - shading AO 10V 8.2 Row Noise AO 10V 8.3 Offset compensation Global offset calibration Dark level is

### Topic 4: Lenses and Vision. Lens a curved transparent material through which light passes (transmit) Ex) glass, plastic

Topic 4: Lenses and Vision Lens a curved transparent material through which light passes (transmit) Ex) glass, plastic Double Concave Lenses Are thinner and flatter in the middle than around the edges.

### Capturing light and color

Capturing light and color Friday, 10/02/2017 Antonis Argyros e-mail: argyros@csd.uoc.gr Szeliski 2.2, 2.3, 3.1 1 Recap from last lecture Pinhole camera model Perspective projection Focal length and depth/field

### Lecture 4: Geometrical Optics 2. Optical Systems. Images and Pupils. Rays. Wavefronts. Aberrations. Outline

Lecture 4: Geometrical Optics 2 Outline 1 Optical Systems 2 Images and Pupils 3 Rays 4 Wavefronts 5 Aberrations Christoph U. Keller, Leiden University, keller@strw.leidenuniv.nl Lecture 4: Geometrical

### PHY 431 Homework Set #5 Due Nov. 20 at the start of class

PHY 431 Homework Set #5 Due Nov. 0 at the start of class 1) Newton s rings (10%) The radius of curvature of the convex surface of a plano-convex lens is 30 cm. The lens is placed with its convex side down

### Chapter 23. Mirrors and Lenses

Chapter 23 Mirrors and Lenses Mirrors and Lenses The development of mirrors and lenses aided the progress of science. It led to the microscopes and telescopes. Allowed the study of objects from microbes

### E X P E R I M E N T 12

E X P E R I M E N T 12 Mirrors and Lenses Produced by the Physics Staff at Collin College Copyright Collin College Physics Department. All Rights Reserved. University Physics II, Exp 12: Mirrors and Lenses

### Prof. Feng Liu. Spring /05/2017

Prof. Feng Liu Spring 2017 http://www.cs.pdx.edu/~fliu/courses/cs510/ 04/05/2017 Last Time Course overview Admin. Info Computational Photography 2 Today Digital Camera History of Camera Controlling Camera

### Lenses- Worksheet. (Use a ray box to answer questions 3 to 7)

Lenses- Worksheet 1. Look at the lenses in front of you and try to distinguish the different types of lenses? Describe each type and record its characteristics. 2. Using the lenses in front of you, look

### Digital Image Processing

Digital Image Processing Digital Imaging Fundamentals Christophoros Nikou cnikou@cs.uoi.gr Images taken from: R. Gonzalez and R. Woods. Digital Image Processing, Prentice Hall, 2008. Digital Image Processing

### Lithography. 3 rd. lecture: introduction. Prof. Yosi Shacham-Diamand. Fall 2004

Lithography 3 rd lecture: introduction Prof. Yosi Shacham-Diamand Fall 2004 1 List of content Fundamental principles Characteristics parameters Exposure systems 2 Fundamental principles Aerial Image Exposure

### Chapter 34 Geometric Optics (also known as Ray Optics) by C.-R. Hu

Chapter 34 Geometric Optics (also known as Ray Optics) by C.-R. Hu 1. Principles of image formation by mirrors (1a) When all length scales of objects, gaps, and holes are much larger than the wavelength

### Advanced Camera and Image Sensor Technology. Steve Kinney Imaging Professional Camera Link Chairman

Advanced Camera and Image Sensor Technology Steve Kinney Imaging Professional Camera Link Chairman Content Physical model of a camera Definition of various parameters for EMVA1288 EMVA1288 and image quality

### Digital Image Fundamentals. Digital Image Processing. Human Visual System. Contents. Structure Of The Human Eye (cont.) Structure Of The Human Eye

Digital Image Processing 2 Digital Image Fundamentals Digital Imaging Fundamentals Christophoros Nikou cnikou@cs.uoi.gr Those who wish to succeed must ask the right preliminary questions Aristotle Images

### Phys214 Fall 2004 Midterm Form A

1. A clear sheet of polaroid is placed on top of a similar sheet so that their polarizing axes make an angle of 30 with each other. The ratio of the intensity of emerging light to incident unpolarized

### Photography PreTest Boyer Valley Mallory

Photography PreTest Boyer Valley Mallory Matching- Elements of Design 1) three-dimensional shapes, expressing length, width, and depth. Balls, cylinders, boxes and triangles are forms. 2) a mark with greater

### Digital Image Processing

Digital Image Processing Digital Imaging Fundamentals Christophoros Nikou cnikou@cs.uoi.gr Images taken from: R. Gonzalez and R. Woods. Digital Image Processing, Prentice Hall, 2008. Digital Image Processing

### Mastery. Chapter Content. What is light? CHAPTER 11 LESSON 1 C A

Chapter Content Mastery What is light? LESSON 1 Directions: Use the letters on the diagram to identify the parts of the wave listed below. Write the correct letters on the line provided. 1. amplitude 2.

### Chapter 23 Study Questions Name: Class:

Chapter 23 Study Questions Name: Class: Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. When you look at yourself in a plane mirror, you

### Vision. By: Karen, Jaqui, and Jen

Vision By: Karen, Jaqui, and Jen Activity: Directions: Stare at the black dot in the center of the picture don't look at anything else but the black dot. When we switch the picture you can look around

### The Optics of Mirrors

Use with Text Pages 558 563 The Optics of Mirrors Use the terms in the list below to fill in the blanks in the paragraphs about mirrors. reversed smooth eyes concave focal smaller reflect behind ray convex

### OPTICS DIVISION B. School/#: Names:

OPTICS DIVISION B School/#: Names: Directions: Fill in your response for each question in the space provided. All questions are worth two points. Multiple Choice (2 points each question) 1. Which of the

### Chapter 17: Wave Optics. What is Light? The Models of Light 1/11/13

Chapter 17: Wave Optics Key Terms Wave model Ray model Diffraction Refraction Fringe spacing Diffraction grating Thin-film interference What is Light? Light is the chameleon of the physical world. Under

### BIOPHYSICS OF VISION GEOMETRIC OPTICS OF HUMAN EYE. Refraction media of the human eye. D eye = 63 diopter, D cornea =40, D lens = 15+

BIOPHYSICS OF VISION THEORY OF COLOR VISION ELECTRORETINOGRAM Two problems: All cows are black in dark! Playing tennis in dark with illuminated lines, rackets, net, and ball! Refraction media of the human

Dr. Shahanawaj Ahamad 1 Outline: Basic concepts underlying Images Popular Image File formats Human perception of color Various Color Models in use and the idea behind them 2 Pixels -- picture elements

### Lecture Notes 10 Image Sensor Optics. Imaging optics. Pixel optics. Microlens

Lecture Notes 10 Image Sensor Optics Imaging optics Space-invariant model Space-varying model Pixel optics Transmission Vignetting Microlens EE 392B: Image Sensor Optics 10-1 Image Sensor Optics Microlens

### Geometrical Optics Optical systems

Phys 322 Lecture 16 Chapter 5 Geometrical Optics Optical systems Magnifying glass Purpose: enlarge a nearby object by increasing its image size on retina Requirements: Image should not be inverted Image

### F-number sequence. a change of f-number to the next in the sequence corresponds to a factor of 2 change in light intensity,

1 F-number sequence a change of f-number to the next in the sequence corresponds to a factor of 2 change in light intensity, 0.7, 1, 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, Example: What is the difference

### brief history of photography foveon X3 imager technology description

brief history of photography foveon X3 imager technology description imaging technology 30,000 BC chauvet-pont-d arc pinhole camera principle first described by Aristotle fourth century B.C. oldest known

### Digital Image Fundamentals and Image Enhancement in the Spatial Domain

Digital Image Fundamentals and Image Enhancement in the Spatial Domain Mohamed N. Ahmed, Ph.D. Introduction An image may be defined as 2D function f(x,y), where x and y are spatial coordinates. The amplitude

### VISUAL PHYSICS ONLINE DEPTH STUDY: ELECTRON MICROSCOPES

VISUAL PHYSICS ONLINE DEPTH STUDY: ELECTRON MICROSCOPES Shortly after the experimental confirmation of the wave properties of the electron, it was suggested that the electron could be used to examine objects

### Lenses. Images. Difference between Real and Virtual Images

Linear Magnification (m) This is the factor by which the size of the object has been magnified by the lens in a direction which is perpendicular to the axis of the lens. Linear magnification can be calculated

### Introduction. Geometrical Optics. Milton Katz State University of New York. VfeWorld Scientific New Jersey London Sine Singapore Hong Kong

Introduction to Geometrical Optics Milton Katz State University of New York VfeWorld Scientific «New Jersey London Sine Singapore Hong Kong TABLE OF CONTENTS PREFACE ACKNOWLEDGMENTS xiii xiv CHAPTER 1:

### Aperture & ƒ/stop Worksheet

Tools and Program Needed: Digital C. Computer USB Drive Bridge PhotoShop Name: Manipulating Depth-of-Field Aperture & stop Worksheet The aperture setting (AV on the dial) is a setting to control the amount

### DOING PHYSICS WITH MATLAB COMPUTATIONAL OPTICS. GUI Simulation Diffraction: Focused Beams and Resolution for a lens system

DOING PHYSICS WITH MATLAB COMPUTATIONAL OPTICS GUI Simulation Diffraction: Focused Beams and Resolution for a lens system Ian Cooper School of Physics University of Sydney ian.cooper@sydney.edu.au DOWNLOAD

### GEOMETRICAL OPTICS AND OPTICAL DESIGN

GEOMETRICAL OPTICS AND OPTICAL DESIGN Pantazis Mouroulis Associate Professor Center for Imaging Science Rochester Institute of Technology John Macdonald Senior Lecturer Physics Department University of

### Image Formation by Lenses

Image Formation by Lenses Bởi: OpenStaxCollege Lenses are found in a huge array of optical instruments, ranging from a simple magnifying glass to the eye to a camera s zoom lens. In this section, we will

### Fundamental Paraxial Equation for Thin Lenses

THIN LENSES Fundamental Paraxial Equation for Thin Lenses A thin lens is one for which thickness is "negligibly" small and may be ignored. Thin lenses are the most important optical entity in ophthalmic

### Conceptual Physics Fundamentals

Conceptual Physics Fundamentals Chapter 13: LIGHT WAVES This lecture will help you understand: Electromagnetic Spectrum Transparent and Opaque Materials Color Why the Sky is Blue, Sunsets are Red, and

### Colour. Why/How do we perceive colours? Electromagnetic Spectrum (1: visible is very small part 2: not all colours are present in the rainbow!

Colour What is colour? Human-centric view of colour Computer-centric view of colour Colour models Monitor production of colour Accurate colour reproduction Colour Lecture (2 lectures)! Richardson, Chapter

### Wallace Hall Academy Physics Department. Waves. Pupil Notes Name:

Wallace Hall Academy Physics Department Waves Pupil Notes Name: Learning intentions for this unit? Be able to state that waves transfer energy. Be able to describe the difference between longitudinal and

### Chapter 28. Reflection and Refraction

Chapter 28 Reflection and Refraction Light takes the path from one point to another that is a. quickest. b. shortest. c. closest to a straight line. d. None of these. Light takes the path from one point

### End-of-Chapter Exercises

End-of-Chapter Exercises Exercises 1 12 are conceptual questions designed to see whether you understand the main concepts in the chapter. 1. Red laser light shines on a double slit, creating a pattern

### Chapter 36: diffraction

Chapter 36: diffraction Fresnel and Fraunhofer diffraction Diffraction from a single slit Intensity in the single slit pattern Multiple slits The Diffraction grating X-ray diffraction Circular apertures

### Human Visual System. Digital Image Processing. Digital Image Fundamentals. Structure Of The Human Eye. Blind-Spot Experiment.

Digital Image Processing Digital Imaging Fundamentals Christophoros Nikou cnikou@cs.uoi.gr 4 Human Visual System The best vision model we have! Knowledge of how images form in the eye can help us with

### Chapter 3 Optical Systems

Chapter 3 Optical Systems The Human Eye [Reading Assignment, Hecht 5.7.1-5.7.3; see also Smith Chapter 5] retina aqueous vitreous fovea-macula cornea lens blind spot optic nerve iris cornea f b aqueous

### Sensation. What is Sensation, Perception, and Cognition. All sensory systems operate the same, they only use different mechanisms

Sensation All sensory systems operate the same, they only use different mechanisms 1. Have a physical stimulus (e.g., light) 2. The stimulus emits some sort of energy 3. Energy activates some sort of receptor