Apparatus, method and recording medium for image stabilization

Patent metadata

Field	Value
Publication number	US-9924097-B2
Application number	US-201615065113-A
Country	US
Kind code	B2
Filing date	Mar 9, 2016
Priority date	Sep 16, 2015
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

An apparatus, a method, and a recording medium for image stabilization are provided. The image stabilization method includes receiving an image that is captured by a camera, detecting a motion of the image, predicting a motion of the image, using a Kalman filter, comparing the detected motion with the predicted motion, and updating a parameter of the Kalman filter based on a result of the comparing.

First claim

What is claimed is:

1. An image stabilization method that is performed by an image stabilization apparatus, the method comprising:
receiving an image that is captured by a camera;
detecting a motion of the image;
predicting a motion of the image, using a Kalman filter; and
increasing a measurement noise variance of the Kalman filter in response to the predicted motion having a fluctuation section, in which an amplitude of the predicted motion is greater than or equal to a first threshold value and the predicted motion fluctuates at a frequency that is greater than or equal to a second threshold.

2. The method of claim 1 , further comprising:
determining an unintentional motion of the image by subtracting the predicted motion from the detected motion; and
compensating for the unintentional motion.

3. The method of claim 1 , wherein the updating the parameter comprising, in response to a difference between the detected motion and the predicted motion being greater than or equal to a third threshold value, determining that over-smoothing occurs and decreasing the measurement noise variance of the Kalman filter to remove an effect of the over-smoothing.

4. The method of claim 1 , further comprising correcting the predicted motion based on the predicted motion and the detected motion.

5. The method of claim 4 , wherein the image is a current frame, and
the method further comprises predicting a motion of a frame next to the current frame based on the corrected predicted motion of the current frame.

6. A non-transitory computer-readable recording medium storing a program to cause a computer to perform the method of claim 1 .

7. An image stabilization method that is performed by an image stabilization apparatus, the method comprising:
receiving an image that is captured by a camera;
detecting a motion of the image;
predicting a motion of the image, using a Kalman filter;
comparing the detected motion with the predicted motion;
updating a parameter of the Kalman filter based on a result of the comparing; and
correcting the predicted motion based on the predicted motion and the detected motion,
wherein the motion is predicted based on an equation:

{

X
^

t
-

=

A
⁢

X
^

t
-
1

P
t
-

=

AP

t
-
1

⁢

A
T

+

S
w

,

wherein {circumflex over (X)} t − is a motion that is predicted from a current frame, {circumflex over (X)} t−1 is a value of correcting a motion that is predicted from a previous frame, A is a state transition matrix, P t − is an error variance regarding the predicted motion {circumflex over (X)} t − , P t−1 , is an error variance regarding the value {circumflex over (X)} t−1 , and S w is a process noise variance.

8. An image stabilization method that is performed by an image stabilization apparatus, the method comprising:
receiving an image that is captured by a camera;
detecting a motion of the image;
predicting a motion of the image, using a Kalman filter;
comparing the detected motion with the predicted motion;
updating a parameter of the Kalman filter based on a result of the comparing; and
correcting the predicted motion based on the predicted motion and the detected motion,
wherein the predicted motion is corrected based on an equation:

{

K
t

=

P
t
-

⁢

C
T

⁡

(

CP
t
-

⁢

C
T

+

S
z

)

-
1

X
^

t

=

Assignees

• Hanwha Techwin Co Ltd

Inventors

• Ryu Yeongeol
• Park Sangji
• Cha Junho
• Noh Seungin

Classifications

• H04N23/6811 Primary

  based on the image signal · CPC title

• G06T7/277 Primary

  involving stochastic approaches, e.g. using Kalman filters · CPC title

• H04N23/683

  performed by a processor, e.g. controlling the readout of an image memory · CPC title

• H04N23/682

  Vibration or motion blur correction · CPC title

• G06T5/50

  using two or more images, e.g. averaging or subtraction · CPC title