Visual Intelligence Chapters 6 & 7. When the World Stopped Moving. 4 th Year Drama and Psych major. Believes she may be quadrichromatic. Tiffany S. Williams. 4 th Year Psych Major Believes Tiffany may be quadrichromatic. Borna Rangchi.
When the World Stopped Moving
4th Year Drama and Psych major.
Believes she may be quadrichromatic.
4th Year Psych Major
Believes Tiffany may be quadrichromatic.
How could you possibly see an object but not its motion?
Phi Motion (Sigmund Exner; 1875)
Two dots are flashed, one after the other.
With the correct interstimulus interval (time and space between dots), two objects are transformed into one moving object.
If ISI is between a half of a second and a tenth of a second, the illusion of motion is created by your visual intelligence. The precise range of ISIs depends on the distance between dots.
ex. If your visual intelligenceopts to construct one object, it will move across the screen rather than two separate blinking objects.
Curved motions can be constructed when no curve is flashed.
Rule 29: Create the simplest possible motions.
“These motions make two dots merge into one, and leave one dot unmatched. You prefer to conserve objects as much as possible when you construct motion. You don’t want to make two objects magically turn into one, and have another object magically appear, when instead you could just make two objects total, and conserve them over the two frames.”
-(Hoffman pg. 148)
…..which leads us to……
Clockwise or Counterclockwise?
Clockwise or Counterclockwise?
Look off to the side for the full experience.
Dunker was ambitious and decided to add yet another light, this time with one at the hub and one to the wheel…
Ted Adelson & Tony Movshon – A “grating.”
“motion orthogonal to its lines” – the motion direction you always make for that particular grating.
You Coordinate your creations of motions and objects by intelligently using size, contrast, depth, and color.
Do u see two independent gratings (combo of 1st and 2nd grating) or one unit?
Differ in size=no integration
The greater the difference the more likely to see 2 independent gratings
Differ in contrast = no integration
The same is true with differences of color and depth.
Points in space move rigidly if all distances between them remain constant during the motion.
Ullman’s Rigidity Theorem: “Suppose you are given three frames, each containing at least four points. If the points are placed at random in each frame, then the probability is zero that they have a rigid interpretation in three dimensions. If the points do have a rigid interpretation, then they almost surely have exactly two interpretations (which are mirror-symmetric).”
It means you don’t need that much info to decide whether or not to create a rigid 3D object and its motion. All you need is as little as 3 frames each having 4 points!
Uh…so what does that mean?
This is advancing the field of computer vision systems. At the moment they are good at constructing 3D objects, but not recognizing them.
Biological Motion – motion of the human body
Eg. Black Light Theater of Prague.
Coming to our own Irvine Barclay Theatre March 19th and 20th
UCI’sBeall Center for Art and Technology explores the idea of biological motion.
Placed lights on joints of actors.
Issue for Rigidity Principle: You can’t have groups of 4 points that move together rigidly.
Knee and ankle points move rigidly, but hip and ankle do not.
You can still construct 3D objects w/o having to create groups of 4 rigid points
Rule 34: If possible, and if other rules permit, interpret image motions as projections of 3D motions that are rigid and planar.
This allows us to construct biologicical motion where rigidity alone, does not.
Because of the biological make up of our joints, our bones swing on planes.
Rigidity and Planarity together require only 2 points to construct a 3D object versus the 4 needed with Ullman’s theorem.
Rigidity and Planarity will usually work with other rules too such as rules about smoothness or dynamical constraints
Motion Picture and Gaming: need compelling graphics or people won’t want it.
When you’re clever:
Interpreting a smooth diagonal movement along the checkerboard along with the shadow.
When you’re not so bright:
Interpreting a complicated movement of varying elevation and direction just because of a different position of the shadow even though the solid sphere is moving along the same exact path!
Tom Albright and Karen Dobkins claim a strong interaction between the magnocellular (motion, luminance, depth, and coarse form) and parvocellular (color, fine form). P. 166
Shows that we prefer objects of the same color to move together.
“Birds of a feather flock together.”
Dr. Hoffman and Dr. Carol Cicerone
The portion of your brain devoted primarily to touch and sensations
Notice how the hand and face are nearby?
The face and arm regions of cortex “invade” the cortex that normally processes the hand.
Proven with magnetic source imaging – a non-surgical process used to measure brain activity. Tony T. Yang (1994)