Digital Image Processing Course Quiz
145 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does a light field image convey about light?

  • The intensity, direction, and speed of the light
  • The intensity and direction of the light (correct)
  • Only the intensity of the light
  • Only the direction of the light

    • What is the purpose of the micro-lens array in a Lytro camera?

  • To capture light from multiple directions (correct)
  • To increase the camera's shutter speed
  • To improve color accuracy
  • To enhance the resolution of the image

    • What happens to areas beyond the depth of field in an image?

  • They remain in focus
  • They appear sharper than the in-focus area
  • They become blurry (correct)
  • They blend with the foreground

    • Which parameters are considered during camera calibration?

    <p>Both internal and external parameters</p> Signup and view all the answers

    How are the internal parameters of a camera useful?

    <p>They help establish the correspondence between a 3D point and its image projection</p> Signup and view all the answers

    What is the term for the difference of projected positions into the left and right images for a given 3D point?

    <p>Disparity</p> Signup and view all the answers

    In stereo vision systems with parallel cameras, which equation relates the disparity and depth derived from the image positions?

    <p>$x_r - x_l = K imes Z$</p> Signup and view all the answers

    What does the term 'epipolar geometry' relate to in stereo vision?

    <p>The relationship between 3D points and their projections in the images</p> Signup and view all the answers

    What geometric concept is illustrated by the intersection between line (Cl, Cr) and the left image plane?

    <p>Epipolar line</p> Signup and view all the answers

    When dealing with stereo vision, what type of search is indicated for matching points across the two images?

    <p>1-D search</p> Signup and view all the answers

    What technique is used to extract 3D information from a multi-view video?

    <p>Structure from Stereo</p> Signup and view all the answers

    Which 3D data acquisition method uses calibrated cameras to triangulate points between two images?

    <p>Stereo Setup</p> Signup and view all the answers

    What type of 3D sensor uses emitted light pulses to measure distance?

    <p>Time of Flight</p> Signup and view all the answers

    Which type of camera is sensitive to light variation and can detect the direction of incoming light?

    <p>Light Field Cameras</p> Signup and view all the answers

    What is a common disadvantage of the Stereo Setup method for 3D imaging?

    <p>Not very precise</p> Signup and view all the answers

    Which of the following defines the primary function of the Structure from Motion technique?

    <p>Creating 3D models from video sequences</p> Signup and view all the answers

    What is a primary characteristic of Depth Cameras?

    <p>Captures RGB plus depth information</p> Signup and view all the answers

    What is the main principle of the Shape from Shading technique?

    <p>Analyzing shadow patterns to determine surface shape</p> Signup and view all the answers

    What is a primary advantage of the Time of Flight (ToF) measurement technique?

    <p>High accuracy due to direct measurement of time of flight</p> Signup and view all the answers

    What is a disadvantage of Continuous Wave Modulation in ToF measurements?

    <p>Motion blur due to low frame-rate</p> Signup and view all the answers

    In comparison to the Kinect, what is a significant strength of the ToF technology?

    <p>Ability to operate both indoors and outdoors</p> Signup and view all the answers

    What technology uses triangulation to create a 3D map?

    <p>Time of Flight</p> Signup and view all the answers

    Which of the following describes a characteristic of the light field cameras created in 2010?

    <p>Formed new perspective views from 4D light field functions</p> Signup and view all the answers

    How is the error in ToF technology primarily caused?

    <p>Light scattering during pulse transmission</p> Signup and view all the answers

    What is the maximum depth range achieved by ToF technology?

    <p>10 m</p> Signup and view all the answers

    What is one of the main differences between ToF technology and structured light systems?

    <p>ToF has lower computational complexity compared to structured light</p> Signup and view all the answers

    What year did Ng publish his PhD thesis and subsequently found the Lytro company?

    <p>2006</p> Signup and view all the answers

    Which element is NOT a characteristic of the Kinect V1 compared to ToF technology?

    <p>Suitable for outdoor environments</p> Signup and view all the answers

    What does the equation P’ = W.P + T represent regarding camera motion?

    <p>The camera's motion combines translation and rotation.</p> Signup and view all the answers

    Under which condition is the rotational component W best approximated?

    <p>When the rotations are small.</p> Signup and view all the answers

    In the context of camera motion, what does the normalization f = 1 imply?

    <p>The focus of the camera is set to a fixed standard.</p> Signup and view all the answers

    What does the variable tz represent in the equations provided?

    <p>The translational velocity along the optical axis.</p> Signup and view all the answers

    What does the term wx in the motion equations refer to?

    <p>The small angular rotation about the Y-axis.</p> Signup and view all the answers

    How does the equation y' = (-wz.x + y + wx + ty/Z) / (wy.x - wx.y + 1 + tz/Z) transform output coordinates?

    <p>It applies a perspective transformation including both rotation and translation.</p> Signup and view all the answers

    Which of the following is a direct consequence of assuming small view angles in camera motion equations?

    <p>Parallax effects can be ignored.</p> Signup and view all the answers

    In the equations for x' and y', what role does the variable Z play?

    <p>It represents the depth of the object from the camera.</p> Signup and view all the answers

    Which of the following correctly describes the transformation equations for camera motion characteristics?

    <p>They elaborate how both translational and rotational factors influence the output.</p> Signup and view all the answers

    What assumption limits the effects of translation according to the provided content?

    <p>Translation along the optical axis is small compared to the distance from the object to the camera.</p> Signup and view all the answers

    What factors influence the color perception of an object?

    <p>Illumination source and human eye characteristics</p> Signup and view all the answers

    Which type of light source is NOT mentioned as influencing color perception?

    <p>LED light</p> Signup and view all the answers

    How does the human brain contribute to color perception?

    <p>It interprets the reflected light from objects.</p> Signup and view all the answers

    What is light classified as in terms of physics?

    <p>Electromagnetic radiation</p> Signup and view all the answers

    Which characteristic of an object affects its color perception?

    <p>The object's absorption and reflection of light</p> Signup and view all the answers

    What is NOT a component of the color perception process?

    <p>Geometric location of the object</p> Signup and view all the answers

    Which of these does NOT contribute to color mixing?

    <p>The time of day</p> Signup and view all the answers

    What is color space used for in digital image processing?

    <p>To represent colors in a defined way</p> Signup and view all the answers

    What is the primary benefit of including black ink in printers?

    <p>To improve the color gamut by increasing density range</p> Signup and view all the answers

    Which of the following correctly describes the arrangement of color filters in digital image sensors?

    <p>It is used to create a color image through interpolation</p> Signup and view all the answers

    Which classification approach for colors focuses on attributes like hue and saturation?

    <p>The visual approach</p> Signup and view all the answers

    In color models, which of the following is NOT a physical approach to classifying colors?

    <p>Munsell</p> Signup and view all the answers

    Which term best describes the relationship between the RGB model and color reproduction?

    <p>It categorizes physical light properties into three channels</p> Signup and view all the answers

    Which light source produces light through a chemical reaction without generating heat?

    <p>Chemical reactions</p> Signup and view all the answers

    What characteristic does a color's 'lightness' attribute refer to?

    <p>The level of darkness or brightness of the color</p> Signup and view all the answers

    What determines the color of the visible spectrum?

    <p>Wavelength and amplitude</p> Signup and view all the answers

    Which of the following is NOT a classification method mentioned for colors?

    <p>CMYK model</p> Signup and view all the answers

    Which of the following best describes the purpose of white balance in imaging technology?

    <p>To ensure colors are captured accurately regardless of lighting</p> Signup and view all the answers

    Which of the following accurately describes color temperature?

    <p>The appearance of color relative to a standard black body</p> Signup and view all the answers

    Which type of light source is characterized by high pressure sodium lamps?

    <p>Gas discharge</p> Signup and view all the answers

    What is a disadvantage of the RGB color model?

    <p>It is difficult to determine the correct values for R, G, and B.</p> Signup and view all the answers

    Which of the following attributes describes the common definition of color?

    <p>Hue</p> Signup and view all the answers

    What is the primary characteristic used to define illuminants?

    <p>Color temperature and spectral power distribution</p> Signup and view all the answers

    What does the term 'perceptually non-linear' imply in color spaces?

    <p>Two points the same distance apart may have different perceived colors.</p> Signup and view all the answers

    Which of the following is responsible for determining brightness in the visible spectrum?

    <p>Amplitude</p> Signup and view all the answers

    Which of the following light sources is an example of incandescence?

    <p>Candle</p> Signup and view all the answers

    Why is it challenging to use the RGB color model for color mixing?

    <p>Determining the proper ratios of R, G, and B is difficult.</p> Signup and view all the answers

    What wavelength range can the human eye perceive?

    <p>780 nm to 380 nm</p> Signup and view all the answers

    What can be said about the range of colors represented by the RGB color model?

    <p>It has a limited range of potential perceivable colors.</p> Signup and view all the answers

    What physical property of light sources is defined by their spectral power distribution?

    <p>Color temperature</p> Signup and view all the answers

    What is the role of chroma in color assessment?

    <p>It identifies the purity or intensity of a color.</p> Signup and view all the answers

    What is one of the primary purposes of color mixing in light sources?

    <p>To produce a wider range of colors</p> Signup and view all the answers

    During color mixing in RGB, what do the values of R, G, and B represent?

    <p>The amounts of primary additive colors.</p> Signup and view all the answers

    What was discovered by color scientists in the mid-19th century regarding color perception?

    <p>Hue, lightness, and chroma best describe conscious color judgments.</p> Signup and view all the answers

    What is measured by perceptual distance among colors according to the perceptual uniform color model?

    <p>The visual similarity between colors</p> Signup and view all the answers

    Which formula is used when Y/Yn is less than or equal to 0.008856 in the perceptual uniform color model?

    <p>L* = 903.292(Y/Yn)</p> Signup and view all the answers

    What color model is utilized by the NTSC standard for commercial color TV broadcasting?

    <p>YIQ color model</p> Signup and view all the answers

    In the perceptual distance equation, d(C1C2) = 0.008856 indicates what?

    <p>C1 and C2 have a perceptual similarity that is negligible</p> Signup and view all the answers

    Which of the following best describes the relationship between perceptual distance and measurable distance in color models?

    <p>Perceptual distance often aligns with measurable distance.</p> Signup and view all the answers

    Which function is applied when calculating the values of a* and b* in the color model when Y/Yn is greater than 0.008856?

    <p>t^(1/3)</p> Signup and view all the answers

    In the context of color spaces, what does Euclidean distance measure?

    <p>The geometric distance between colors in RGB space</p> Signup and view all the answers

    What is the result of the transformations applied to the colors according to the perceptual uniform color model?

    <p>A more accurate perception of color similarity</p> Signup and view all the answers

    How does the surrounding color affect the perception of the central square's brightness?

    <p>A darker surrounding color makes the square appear lighter.</p> Signup and view all the answers

    Which of the following conditions can occur due to color blindness?

    <p>Inability to perceive all colors equally.</p> Signup and view all the answers

    Which classification of color blindness is characterized by a defect in the L-cone?

    <p>Protanomaly</p> Signup and view all the answers

    What is the incidence percentage of dichromacy in males?

    <p>2.4%</p> Signup and view all the answers

    What condition is associated with the absence of L-cones?

    <p>Protanopia</p> Signup and view all the answers

    Which type of color deficiency leads to an inability to perceive blue-yellow colors?

    <p>Tritanopia</p> Signup and view all the answers

    What is the main purpose of the Ishihara test?

    <p>To diagnose color blindness.</p> Signup and view all the answers

    Which statement best describes the phenomenon of complementary contrast?

    <p>The central square appears brightly against a complementary color.</p> Signup and view all the answers

    Which condition represents the complete lack of cone cells?

    <p>Rod Monochromacy</p> Signup and view all the answers

    How does saturation contrast affect color perception?

    <p>It makes the central color appear less vibrant.</p> Signup and view all the answers

    In which color mixing method does the addition of colors result in white?

    <p>Additive color mixing</p> Signup and view all the answers

    What does color naming entail?

    <p>Attaching labels to colors.</p> Signup and view all the answers

    What color perception effect occurs when a central square appears blue surrounded by green?

    <p>Hue contrast effect</p> Signup and view all the answers

    Which of the following is a form of anomalous trichromacy?

    <p>Protanomaly</p> Signup and view all the answers

    What component of the YCrCb color model encodes the luminance in a video signal?

    <p>Y</p> Signup and view all the answers

    What is the correct representation of the luminance calculation in color spaces?

    <p>Y = 0.299R + 0.587G + 0.114B</p> Signup and view all the answers

    Which matrices are used for calculating the color difference signals in the YCrCb color model?

    <p>R-Y and B-Y</p> Signup and view all the answers

    How are the I and Q components typically encoded in a video signal compared to the Y component?

    <p>Y is encoded using less bandwidth than I and Q.</p> Signup and view all the answers

    In the context of the YCrCb model, what are the components Cr and Cb responsible for?

    <p>Representing chromaticity or color information.</p> Signup and view all the answers

    Which factor does NOT influence the color perception of an object?

    <p>Wavelength of emitted light</p> Signup and view all the answers

    What is the primary reason different types of light sources affect color perception?

    <p>They produce various wavelengths</p> Signup and view all the answers

    What characteristic of objects determines which wavelengths of light are absorbed or reflected?

    <p>Material composition</p> Signup and view all the answers

    How does the human brain contribute to color interpretation?

    <p>By comparing colors to a standard reference</p> Signup and view all the answers

    Which of these elements is NOT a component of the color perception process?

    <p>Viewer's emotional state</p> Signup and view all the answers

    What is one way color mixing differs from color perception?

    <p>Color mixing involves physical substances</p> Signup and view all the answers

    Which statement best describes color spaces in digital image processing?

    <p>They provide a method for quantifying color representations</p> Signup and view all the answers

    Which statement correctly describes the CIE 1976 UCS diagram?

    <p>The scales of the chromaticity diagram are not uniform.</p> Signup and view all the answers

    What is the formula for calculating the chromaticity coordinate u'?

    <p>u' = 4X + 15Y + 3Z</p> Signup and view all the answers

    What is meant by 'just noticeably different' (JND) in the context of color mixing?

    <p>The minimal change in color that can be perceived by the human eye.</p> Signup and view all the answers

    Why are the ellipses in the 1976 chromaticity diagram plotted at ten times their actual size?

    <p>To emphasize color boundaries visually.</p> Signup and view all the answers

    Which aspect of the CIE 1976 chromaticity diagram is highlighted compared to earlier models?

    <p>Its chromaticity coordinates are more uniformly distributed.</p> Signup and view all the answers

    What are the three colormaking attributes identified by color scientists in the 19th century?

    <p>Hue, lightness, and chroma</p> Signup and view all the answers

    Which limitation is associated with the RGB color model?

    <p>It covers a small range of perceivable colors.</p> Signup and view all the answers

    What does the term 'perceptually non-linear' refer to in the context of color spaces?

    <p>It implies equal distances may not indicate equal perceptual differences.</p> Signup and view all the answers

    In the RGB color model cube representation, what do the corners represent?

    <p>All possible colors.</p> Signup and view all the answers

    Which color is NOT one of the secondary colors formed through RGB color mixing?

    <p>Green</p> Signup and view all the answers

    What does hue correspond to in color classification?

    <p>The common name of a color, like 'red' or 'blue.'</p> Signup and view all the answers

    Which of the following correctly describes a problem related to the RGB color model?

    <p>It is difficult to determine the exact RGB values for a given color.</p> Signup and view all the answers

    Which color mixing concept illustrates how colors combine in the RGB model?

    <p>Additive mixing</p> Signup and view all the answers

    What happens to the appearance of a central square when placed against a darker surrounding color?

    <p>The square appears lighter.</p> Signup and view all the answers

    Which type of color blindness is characterized by the absence of L-cones?

    <p>Protanopia</p> Signup and view all the answers

    What is the main visual effect of complementary colors when positioned adjacent to each other?

    <p>One color appears more vibrant.</p> Signup and view all the answers

    How is color naming defined?

    <p>Attaching labels to specific colors.</p> Signup and view all the answers

    Which color vision deficiency is the most common among males?

    <p>Deuteranomaly</p> Signup and view all the answers

    What effect do surrounding colors have on the perception of the central square’s hue?

    <p>They shift the perceived hue.</p> Signup and view all the answers

    Which type of color blindness affects individuals with S-cone defects?

    <p>Tritanomaly</p> Signup and view all the answers

    What characteristic of colors does saturation contrast emphasize?

    <p>Color richness.</p> Signup and view all the answers

    Which vision deficiency is characterized by a defect in M-cones?

    <p>Deuteranopia</p> Signup and view all the answers

    What is the incidence percentage of normal vision in the population?

    <p>Approximately 90%</p> Signup and view all the answers

    Which contrast effect occurs when a colored area appears differently based on surrounding colors?

    <p>Hue contrast</p> Signup and view all the answers

    What test is commonly used to identify color blindness?

    <p>Ishihara Test</p> Signup and view all the answers

    What type of contrast can cause a square to appear brighter against a gray background?

    <p>Lightness contrast</p> Signup and view all the answers

    What does the equation $C = rc(R) + gc(G) + bc(B)$ represent?

    <p>An equation for determining color composition from red, green, and blue components</p> Signup and view all the answers

    In the CIE xyY color space, which of the following is used to represent brightness?

    <p>Y</p> Signup and view all the answers

    What is the dominant wavelength ($ ext{λD}$) of a color that can be located at point (0.2, 0.6) on the chromaticity diagram?

    <p>512nm</p> Signup and view all the answers

    What does purity (saturation) indicate in color perception?

    <p>The distance from the white point to the boundary in color space</p> Signup and view all the answers

    How are colors determined to be complementary in the context of the chromaticity diagram?

    <p>By finding colors on opposite segments from the white point</p> Signup and view all the answers

    In additive color mixing, which formula correctly describes the mixing of three colors?

    <p>P = $ ext{α} P1 + ext{β} P2 + ext{γ} P3$</p> Signup and view all the answers

    What does the term 'gamut coverage' refer to in color spaces?

    <p>The range of colors that a device can produce</p> Signup and view all the answers

    What do Mac Adam’s ellipses represent in color perception?

    <p>Regions of equal color difference perceived by the human eye</p> Signup and view all the answers

    Which variable in the equation for three-color mixing represents the contribution of the third color?

    <p>$ ext{γ}$</p> Signup and view all the answers

    Which coordinate system is primarily affected by the chromaticity coordinates x and y?

    <p>XYZ color space</p> Signup and view all the answers

    What type of color mixing combines specific values of two colors to produce an output color?

    <p>Additive color mixing</p> Signup and view all the answers

    Which of the following accurately describes the relationship of x, y, and z in the CIE xyY color space?

    <p>x + y + z = 1</p> Signup and view all the answers

    What characteristic is essential when determining the purity of a color?

    <p>The distance from the color point to the white point</p> Signup and view all the answers

    Study Notes

    Digital Image Processing

    Introduction to 3D Processing

    • Core areas: Computer Graphics, Signal/Image Processing, TV & Movies
    • Computer Graphics involves modeling, creating, manipulating, and animating 3D objects, including realistic rendering of synthetic scenes (e.g., ray tracing, Z-buffer).
    • Signal/Image Processing methods extract 3D scene information from (multi-view) videos, including structure from motion, structure from stereo, shape from shading, and structure from zooming.
    • Customizing algorithms for 3D data (like compression) is also part of this area.
    • TV and Movies leverage stereoscopic visualization for real or virtual scenes.

    3D Data Acquisition (2.5D & 3D)

    • Methods include creating 3D meshes and textures from scratch.
    • Employing specific sensors (active or passive):
      • Multi-view acquisitions (including stereoscopic)
      • 3D scanners like Minolta or Cyberware

    Depth Cameras (RGB-D)

    • Includes Stereo Setup, Time of Flight, Structured light, Light Field:
      • Stereo Setup (Passive system): Uses two calibrated cameras to find and match points between images for distance estimation. Less precise than other methods. Not reliable without textured surfaces.
      • Time of Flight: Measures the time it takes for light pulses to travel to an object and back. High resolution and precision, but primarily an indoor technology.
      • Structured Light: Projects a pattern of light onto a scene, and analyses the resulting distortion to determine depth. Fast and precise, but mostly used indoors.
      • Light Field: Passive system that tracks the direction of light. Detects light variation. Works indoors and outdoors, but sensitivity to specific light variations is a factor.

    What is a ToF Camera?

    • Provides intensity and range data simultaneously for every pixel.
    • One IR emitter and one detector.
    • Estimation of distance by measuring the time taken for a light pulse to reach a target and return.
    • Advantages: Direct measurement of time of flight, limited background illumination influence, and collinear emitter/detector directions.
    • Disadvantages: Requires high accuracy, susceptible to light scattering, and challenges with pulse generation.

    ToF Principles - Continuous Wave Modulation

    • Advantages: Can use various light sources, has different modulation techniques, and provides simultaneous range and amplitude images.
    • Disadvantages: Long integration time, results in low frame rate and motion blur.

    Kinect

    • Projects a pseudo-random IR light pattern into a scene.
    • The CMOS IR camera captures the distortion of the pattern to create a 3D map.
    • Different speckle sizes correspond to different distance regions.

    ToF vs Kinect

    • ToF:
      • Outdoor/indoor capability
      • Greater depth range (up to 30m extendable)
      • Millimeter (mm) depth accuracy
      • Higher resolution (200x200 pixels)
      • Pulsed/continuous wave modulation
      • Onboard FPGA for phase and intensity measurement
      • Industrial market
      • Higher price (3000€)
    • Kinect V1:
      • Indoor use
      • Shorted depth range (3.5m)
      • Centimeter (cm) depth accuracy
      • Lower resolution (640x480 pixels)
      • Triangulation method
      • High computation cost (parallel processor)
      • Targeting video games market
      • Lower price (150€)

    Light Field History

    • 1991: Adelson and Bergen introduce the plenoptic function.
    • 1996: Levoy and Hanrahan discuss the light field function.
    • 2005: Wilburn creates gantry cameras.
    • 2006: Ng's PhD thesis and Lytro company founding.
    • 2010: Commercial Lytro and Raytrix light field cameras emerge.

    Light Field Cameras

    • Use a coded mask (transparency) and a sensor.

    Comparison with Other 3D Technologies

    • Summarizes comparison of Time of Flight, Stereovision, Structured Light, and Light Field techniques across various aspects like resolution, precision, performance, computation complexity, and data format.

    Lytro Camera

    • Light field images capture light information, including intensity and direction of light source.
    • Inserts micro-lens array between the sensor and lens for light field capture.

    Calibration: Internal & External Parameters

    • Internal parameters: focal length, projection of the optical center in the image plane.
    • External parameters: translation, rotation information and camera orientation in space.

    Internal Parameters

    • Understanding internal parameters allows associating a scene point with its corresponding image point.

    Structure from Stereo

    • Stereo vision systems generate two images of a scene from different viewpoints.
    • Disparity measures the difference in projected positions of a 3D point in left and right images.
    • Depth is derived from disparity, especially when the cameras are parallel.

    Epipolar Geometry

    • Key concept in stereo vision systems.
    • Epipolar lines and points are important for effectively searching for corresponding points in image pairs.

    Structure from Motion

    • Decomposes relative object motion into rotational and translational components.
    • Assumes small rotations, small view angles and small translation along the optical axis compared to object-camera distance.
    • Computes simplified equations for calculating 2D/3D motion and depth.

    2D/3D Planar Facet Equations

    • Simplified 2D/3D equations for planar facets (planar surface, plane), a crucial step for efficient calculations.

    (auto) Stereoscopic Visualization

    • Methods for display of 3D images to human eyes (glasses or glasses-free techniques).

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Description

    Test your knowledge on Digital Image Processing and 3D Processing concepts. This quiz covers key areas such as computer graphics, image processing methods, and data acquisition techniques. Explore the fascinating world of 3D modeling and synthetic scene rendering.

    More Like This

    Understanding Stereopsis and 3D Vision
    5 questions

    3D Vision Test: Understanding Stereopsis and Three Dimensional Vision

    HandsomeAstronomy avatar
    HandsomeAstronomy
    3D Reconstruction Methods
    10 questions

    3D Reconstruction Methods

    DignifiedJupiter751 avatar
    DignifiedJupiter751
    Processing - the machine
    5 questions

    Processing - the machine

    EquitableModernism avatar
    EquitableModernism
    Infographie 3D et Traitement d'Image
    8 questions

    Infographie 3D et Traitement d'Image

    ExhilaratingVoice avatar
    ExhilaratingVoice
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser