Homework 08 Solution

$30.00 $24.00

Name: ⃗ that satisfies the Optical Flow 1. Smallest Optical Flow (4 pts): What velocity Constraint Equation + ⃗ + = 0 has the smallest magnitude | |? Hint: This can be solved geometrically as was outlined in class by considering the OFCE in , space. v (0,− (− ,0) u 2. Moving Gaussian Blob…

5/5 – (2 votes)

You’ll get a: zip file solution

 

Categorys:
Tags:

Description

5/5 – (2 votes)

Name:

that satisfies the Optical Flow

1. Smallest Optical Flow (4 pts): What velocity

Constraint Equation

+

+ = 0 has the smallest magnitude | |? Hint: This can be

solved geometrically as was outlined in class by considering the OFCE in , space.

v

(0,−

(− ,0)

u

2. Moving Gaussian Blob (6 (pts): , , A) Gaussian=1 blob is observed over2 time to have brightness

2 2( 2−2( 1+ 2) +( 1+ 2) )

  1. What are , , and ? Hint: You should find that these derivatives have a simple form.

  1. The Optical Flow Constraint Equation is + + = 0. Write this out using the results of Part a. and simplify it as much as possible. For example, you should be able to cancel terms that occur in each of , , and .

( , , ) =

+ 1

[( −

)2

+(− )2

]

3. Quadratic Optical Flow (8 pts : Suppose the image brightness is given by

0

2

1

2

  1. What are Ix, Iy, and It? Hint: You should find that these derivatives have a simple form.

  2. Express the Optical Flow Constraint Equation + + = 0 in the simplest terms possible for this image sequence.

  1. The equation from b. must hold for all x, y, and t. Find a constant solution for u and v that makes this true, that is, such that u and v do not depend on x, y, and t.

flow, where at each iteration, the optical flow ( , ), ( , ) is updated according to

4. Iterative Optical Flow(8 pts): We saw in class an iterative method for computing optical

( , )

new

2

+ 4

1

old( ) −

= [

neighbors( , )

old

[ ( , )]

2+4]

( ) −

neighbors( , )

a. Show that this is equivalent to

2

+ 4

old( ) −

( , )

new

1

neighbors( , )

[ ( , )]

=

4

2 + 4 2

+ 16

[

2

+ 4]

old

( ) −

neighbors( , )

( , )

= ̅

(

̅

+

̅

+ )

b. Show that this is equivalent to update equations

new

old

4

old

old

2

+ 2

+

( , ) = ̅

(

̅

+

̅

+ )

new

old

4

old

old

2

+ 2

+

where ̅

old

old

, ̅

are the averages of the 4 neighbors of ( , ), ( , ). Hint: You only

need to show this for new because

new follows an identical derivation.

c. In the case that

= 0, what do the update equations reduce to?

Homework 08 Solution
$30.00 $24.00