Method for compensating motion blur in connection with vibrations

Patent metadata

Field	Value
Publication number	US-9332186-B2
Application number	US-201314410040-A
Country	US
Kind code	B2
Filing date	Jun 11, 2013
Priority date	Jun 20, 2012
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

The invention relates to a method for compensating motion blur in connection with vibrations in an image recording apparatus ( 1 ), such as a camera, for stabilization of recorded images, wherein use is made of a reference image. According to the invention, a frame ( 2 ) of a recorded image is selected for image stabilization and the degree of sharpness ( 3 ) in the selected frame is evaluated and compared ( 5 ) with a previously saved reference value ( 4 ) for the degree of sharpness for a previously selected frame. The last chosen frame is used to update ( 6 ) a video sequence and the degree of the sharpness for the last chosen frame is saved ( 7 ) as a new reference value if the degree of sharpness for the last chosen frame is deemed to be better ( 5 ) than or equally as good as the reference value for the degree of sharpness for a previously selected frame. The reference value ( 4 ) for the degree of sharpness for a previously selected frame is saved with reduction ( 8 ) of the value of sharpness and the previously selected frame is used in the video sequence if the degree of sharpness for the last chosen frame is deemed to be worse ( 5 ) than the reference value for the degree of sharpness for the previously selected frame. As a result of the invention, a method which, by relatively simple action, can effectively compensate for motion blur in connection with vibrations is provided.

First claim

The invention claimed is:

1. A method for processing image data for image stabilization, the method comprising:
receiving an image from an image recording device;
selecting a portion of the received image;
determining a degree of sharpness the selected portion of the received image;
comparing the determined degree of sharpness for the selected portion of the received image against a reference value, the reference value representing a degree of sharpness for a select portion of a previously used image in a video sequence;
updating the video sequence with the received image and saving the determined degree of sharpness for the selected portion of the received image as a new reference value, if the determined degree of sharpness is greater than or equal to the reference value; and
reducing the reference value, saving the reduced reference value as the new reference value, and keeping the previously used image in the video sequence, if the determined degree of sharpness is less than the reference value.

2. The method according to claim 1 , wherein the portion of the image is selected from a central portion of the image.

3. The method according to claim 1 , wherein the portion of the image is selectable by a user of the image recording device.

4. The method according to claim 1 , wherein the method is performed for image stabilization in response to an activation by a user of the image recording device.

5. The method according to claim 1 , wherein the image recording device comprises an infrared (IR) camera, and wherein the receiving of the image comprises receiving an IR Image from the IR camera.

6. The method according to claim 1 , wherein the degree of sharpness for the selected portion of the received image is determined by an application of an edge-detecting filter.

7. The method according to claim 6 , wherein the edge-detecting filter comprises a use of a Tenengrad operator.

8. The method according to claim 6 , wherein the edge-detecting filter comprises calculation of simple standard deviation for each pixel included in the selected portion of the received image.

9. The method according to claim 1 , wherein the method is used in connection with autofocusing of a camera.

10. The method according to claim 1 , wherein the reducing of the reference value is repeated for each new selected image portion for which the determined degree of sharpness is less than the reference value.

11. The method according to claim 10 , wherein the reducing of the reference value is executed with the same percentage of the reference value for each repeated reducing.

12. The method according to claim 10 , wherein the number of times that the reducing of the reference value is permitted is limited.

13. The method according to claim 10 , wherein the reducing of the reference value is executed progressively.

14. A camera adapted for processing image data, the camera comprising:
a sensor configured to acquire an image; and
an image processor configured to:
select a portion of the acquired image,
determine a degree of sharpness in the selected portion of the acquired image,
compare the determined degree of sharpness for the selected portion of the acquired image against a reference value, the reference value representing a degree of sharpness for a previously used image in a video sequence,
update the video sequence with the acquired image and save the determined degree of the sharpness for the selected portion of the acquired image as a new reference value, if the determined degree of sharpness is greater than or equal to the previously used reference value, and
reduce the reference value, save the reduced reference value as the new reference value, and keep the previously used image in the video sequence, if the determined degree of sharpness is less than the reference value.

15. The camera according to claim 14 , wherein the portion of the image is selected, from a central portion of the image.

16. The camera according to claim 14 , wherein the portion of the image is selectable by a user of the camera.

17. The camera according to claim 14 , wherein the sensor comprises an infrared (IR) sensor configured to acquire an IR image.

18. The camera according to claim 14 , wherein the degree of sharpness for the selected portion of the acquired image is determined by an application of an edge-detecting filter.

19. The camera according to claim 14 , wherein the image processor is configured to repeat reduction of the reference value for each new selected image portion for which the determined degree of sharpness is less than the reference value.

20. The camera according to claim 19 , wherein the image processor is configured to reduce of the reference value with substantially the same percentage of the reference value for each repeated reduction.

Assignees

• Flir Systems Ab

Inventors

• Johansson Emanuel
• Larson Odd
• Waldreus Erland

Classifications

• H04N23/60

  Control of cameras or camera modules · CPC title

• H04N23/6811

  based on the image signal · CPC title

• H04N23/6845

  by combination of a plurality of images sequentially taken · CPC title

• H04N23/683 Primary

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

• G06T5/003

  Physics · mapped topic