chapter 5 perceiving objects and scenes n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Chapter 5: Perceiving Objects and Scenes PowerPoint Presentation
Download Presentation
Chapter 5: Perceiving Objects and Scenes

Loading in 2 Seconds...

play fullscreen
1 / 68

Chapter 5: Perceiving Objects and Scenes - PowerPoint PPT Presentation


  • 185 Views
  • Uploaded on

Chapter 5: Perceiving Objects and Scenes. Figure 5-3 p97. Why Is It So Difficult to Design a Perceiving Machine?. The stimulus on the receptors is ambiguous. Inverse projection problem: An image on the retina can be caused by an infinite number of objects. Objects can be hidden or blurred.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Chapter 5: Perceiving Objects and Scenes


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
    Presentation Transcript
    1. Chapter 5: Perceiving Objects and Scenes

    2. Figure 5-3 p97

    3. Why Is It So Difficult to Design a Perceiving Machine? • The stimulus on the receptors is ambiguous. • Inverse projection problem: An image on the retina can be caused by an infinite number of objects. • Objects can be hidden or blurred. • Occlusions are common in the environment.

    4. Figure 5-6 p98

    5. Figure 5-7 p98

    6. http://www.darkroastedblend.com/2010/09/mind-bending-optical-illusions.htmlhttp://www.darkroastedblend.com/2010/09/mind-bending-optical-illusions.html • http://www.youtube.com/watch?v=trKn04N2c1g

    7. Why Is It So Difficult to Design a Perceiving Machine? - continued • Objects can be hidden or blurred

    8. Figure 5-8 p99

    9. Figure 5-9 p99

    10. Why Is It So Difficult to Design a Perceiving Machine? - continued • Objects look different from different viewpoints • Viewpoint invariance: the ability to recognize an object regardless of the viewpoint • This is a difficult task for computers to perform

    11. Figure 5-10 p99

    12. http://www.youtube.com/watch?v=-n0FwA9SLQw

    13. Perceptual Organization • Approach established by Wundt (late 1800s) • States that perceptions are created by combining elements called sensations • Structuralism could not explain apparent movement • Stimulated the founding of Gestalt psychology in the 1920s by Wertheimer, Koffka, and Kohler • The whole differs from the sum of its parts. • Perception is not built up from sensations, but is a result of perceptual organization.

    14. Figure 5-14 p101

    15. Figure 5-11 p100

    16. Figure 5-12 p100

    17. Figure 5-13 p100

    18. Figure 5-15 p101

    19. Perceptual Organization - continued • Illusory contours- contours that appear real but have no physical edge

    20. Figure 5-16 p102

    21. Gestalt Organizing Principles • Principles of perceptual organization. • Good continuation - connected points resulting in straight or smooth curves belong together • Lines are seen as following the smoothest path • Pragnanz - every stimulus is seen as simply as possible • Similarity - similar things are grouped together

    22. Figure 5-17 p102

    23. Figure 5-18 p102

    24. Figure 5-19 p103

    25. Gestalt Organizing Principles - continued • Proximity - things that are near to each other are grouped together • Common fate - things moving in same direction are grouped together • Common region - elements in the same region tend to be grouped together • Uniform connectedness - connected region of visual properties are perceived as single unit

    26. Figure 5-22 p103

    27. Figure 5-23 p104

    28. Figure 5-24 p104

    29. Perceptual Segregation • Figure-ground segregation - determining what part of environment is the figure so that it “stands out” from the background • Properties of figure and ground • The figure is more “thinglike” and more memorable than ground. • The figure is seen in front of the ground. • The ground is more uniform and extends behind figure. • The contour separating figure from ground belongs to the figure (border ownership).

    30. Figure 5-25 p105

    31. Figure 5-26 p105

    32. Perceptual Segregation - continued • Factors that determine which area is figure: • Elements located in the lower part of displays • Convex side of borders

    33. Figure 5-27 p105

    34. Figure 5-28 p106

    35. Subjective Factors That Determine Which are is Figure • Gestalt psychologists believed that experience and meaning play a minor role in perceptual organization. • Gibson Experiment showed that figure-ground can affected by meaningfulness of a stimulus.

    36. Figure 5-31 p107

    37. Figure 5-32 p108

    38. Perceiving Scenes and Objects in Scenes • A scene contains: • background elements. • objects organized in meaningful ways with each other and the background. • Difference between objects and scenes • A scene is acted within • An object is acted upon

    39. Perceiving Scenes and Objects in Scenes - continued • Research on perceiving gists of scenes • Potter showed that people can do this when a picture is only presented for 1/4 second • Fei-Fei used masking to show that the overall gist is perceived first followed by details.

    40. Figure 5-33 p109

    41. Perceiving Scenes and Objects in Scenes - continued • Global image features of scenes • Degree of naturalness • Degree of openness • Degree of roughness • Degree of expansion • Color • Such features are holistic and perceived rapidly

    42. Figure 5-35 p110

    43. Regularities in the Environment: Information for Perceiving • Physical regularities - regularly occurring physical properties • Oblique effect - people perceive horizontals and vertical more easily than other orientations • Uniform connectedness - objects are defined by areas of the same color or texture

    44. Regularities in the Environment: Information for Perceiving – continued • Physical regularities - regularly occurring physical properties • Homogenous colors and nearby objects have different colors • Light-from-above heuristic - light in natural environment comes from above us

    45. Figure 5-36 p111

    46. Figure 5-37 p111

    47. Figure 5-38 p112

    48. Regularities in the Environment: Information for Perceiving - continued • Palmer experiment • Observers saw a context scene flashed briefly, followed by a target picture. • Results showed that: • Targets congruent with the context were identified 80% of the time . • Targets that were incongruent were only identified 40% of the time.

    49. Figure 5-39 p113

    50. Figure 5-40 p113