Robotics 2
Machine Vision: Motion
Quiz   The optical flow mask is a mask in three dimensions   Question 3:  Which of these is a benefit of the optical flow method compared to the difference method?
Question 2: Which of these is a benefit of the difference method compared to optical flow?
Question 1:  Which of these are methods for detecting motion?
Background subtraction and masking
The difference method and optical flow
Support vector machine and artificial neural networks
The differential method and optical masking
The difference method gives information about motion direction and speed
The difference method is computationally simple and can be computed quickly
The difference method is based on masking
The difference method can tell us the location of the motion Question 4:  Which of these describes how the motion by difference method works?
We calculate the separability between one image and the next Question 5:  Which of these describes how the optical flow method works? We calculate the difference in time between two similar images
We find the difference between the current image and the image from one time step in the past
We apply a mask that is designed to look for differences in the image in the time dimension
Question 7:  Suppose I want my robot to know how fast, and in what direction objects are moving.  Which method should I use?
Question 8:  What makes the mask used in optical flow different than the masks we used previously for things like image noise reduction?
Question 9:  Why is optical flow so much more computationally-intensive than motion by difference?
Question 10:  In Optical flow, what is the mask that is used designed to detect?
The optical flow method gives information about motion direction and speed
The optical flow method is computationally simple and can be computed quickly
The optical flow method is based on image subtraction
The optical flow method can tell us the location of the motion Optical flow, because it is the only method that tells us where motion is happening
The difference method, because it is computationally simpler than optical flow
Question 6:  Suppose that I just want my robot to know where motion is happening in its field of view.  Which method should I use?
The optical flow mask includes color information
The optical flow mask is a 10x10 mask, much larger than the masks we used previously
The optical flow mask uses bigger numbers than our previous masks
Because it is based on masking, which is computationally-intensive
Because it uses the time dimension; motion by difference ignores time
Because it uses a network of artificial neurons
Because we need to process every image many times
We calculate the difference in time between two similar images
We find the difference between the current image and the image from one time step in the past
We calculate the separability between one image and the next
We apply a mask that is designed to look for differences in the image in the time dimension
Optical flow, because it is the only method that tells us how fast, and in what direction objects are moving
The difference method, because it is computationally simpler than optical flow
The mask is designed to detect changes in pixel values in the time dimension
The mask is designed to detect noise in the image
The mask is designed to detect the edges of objects
The mask is designed to detect brightness changes in the X and Y directions