Method for Correcting an Acquired Image

• US 20170243330A1
• Filed: 02/19/2016
• Published: 08/24/2017
• Est. Priority Date: 02/19/2016
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: FotoNation Limited (Adeia Inc.)
• Inventors: Stec, Piotr
• Granted Patent: US 9,934,559 B2
• Time in Patent Office: Days
• CPC Class Codes: G06T 2207/20201 Motion blur correction
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: H04N 23/681 Motion detection
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/683 performed by a processor, e.g. controlling the readout of an image memory
• CPC Class Codes: H04N 23/689 Motion occurring during a rolling shutter mode

Abstract

A method of correcting an image obtained by an image acquisition device includes obtaining successive measurements, G_n, of device movement during exposure of each row of an image. An integration range, idx, is selected in proportion to an exposure time, t_e, for each row of the image. Accumulated measurements, C_n, of device movement for each row of an image are averaged across the integration range to provide successive filtered measurements, G, of device movement during exposure of each row of an image. The image is corrected for device movement using the filtered measurements G.

Claims

1. A method of correcting an image obtained by an image acquisition device including:

obtaining successive measurements, G_n, of device movement during exposure of each row of an image;

selecting an integration range, idx, in proportion to an exposure time, t_e, for each row of the image,

averaging accumulated measurements, C_n, of device movement for each row of an image across said integration range to provide successive filtered measurements, G, of device movement during exposure of each row of an image, and

correcting said image for device movement using said filtered measurements G.

2. A method according to claim 1 wherein said integration range, idx, is calculated dependent on a sampling frequency F for said measurements of device movement and said exposure time t_e as follows:

idx=F*t_e

3. A method according to claim 1 wherein said averaging comprises calculating said filtered measurements G as follows:

G=(C_n−

C<sub>n−

idx</sub>)/idx where C_n is an accumulated value corresponding to measurement G_n and C<sub>n−

idx</sub> is an accumulated value corresponding to measurement G<sub>n−

idx</sub> at the start of said integration range.

4. A method according to claim 1 wherein said measurements of device movement comprise any of:

gyroscope, accelerometer or magnetometer measurements.

5. A method according to claim 1 wherein said image comprises a still image or an image within a sequence of images.

6. A method according to claim 1 wherein said rows of said image are acquired during successive exposure times, t_I, said measurements of device movement corresponding to respective exposure times.

7. A processing unit for an image acquisition device arranged to correct an image according to the method of claim 1.