Perception 3.2 Flashcards
When you are looking at the page of the book
what happens?
Image cast by the borders on your retina is ambiguous
Rectangular shape of the page is obvious
We know the page’s shape and distance from eye
It will be easy to determine its image on the retina by applying geometric principles
However, perceputal system not concerned with determining an object’s image on the retina but the other way around
starts with image on the retina and determine object out there created the image
What is the inverse projection problem
Task of determining the object responsible for a particular image on the retina
What does inverse projection principle start with?
Retinal image
Figure 3,5
Why is the image on the retina ambiguous?
- Retinal image created by the rectangular page could be created by a number of different objects including the rectangular page but also titled trapezoid and much larger rectangle and infit number of objects located at different distances
- particular image on the retina can be created by many different objects in the environment, it is easy to see why we say that the image on the retina is ambiguous and that we thus somehow need to figure out what exactly has been presented to us.
When does problem of hidden objects ocucr?
Anytime one object obscures part of another object
When does the problem of a hidden object occur and how do people overcome this?
- Occurs frequently in the environment but people easily understand that the part of the object that is covered continues to exist
- People use their knowledge of the environment to determine what is likely to be present
How do people recongise objects that are not in sharp focus
- Despirate degraded nature of images people can often identify most of them where computers perform poorly on the task
Problem percieving machine is that objects are viewed at?
Different angles
Images of objects are continually changing depending on the angle they are periceved
How can humans percieve this image?
- This is not obvious to computer
- Ability to recognise an object seen from different viewpoints is called viewpoint invariance
Whast is viewpoint invariance?
The ability to recognize an object seen from different viewpoints.
People can typically identify a chair whether they are viewing it from behind, in front or from the side. This is referred to as
viewpoint invariance.
The task of determining the object responsible for a particular image on the retina is called the _____ problem.
inverse projection
The task of determining the object responsible for a particular image on the retina is called the inverse projection problem, because it involves starting with the retinal image and extending rays out from the eye.
The ambiguous stimulus issue refers to the observation that
a particular image on the retina can often be produced by different objects in the environment.
