Removal of A-scan streaking artifact

• US 9,324,141 B2
• Filed: 10/02/2013
• Issued: 04/26/2016
• Est. Priority Date: 10/05/2012
• Status: Expired due to Fees

• Current Assignee: Volcano Corporation (Koninklijke Philips N.V.)
• Original Assignee: Volcano Corporation (Koninklijke Philips N.V.)
• Inventors: Begin, Elizabeth
• Primary Examiner(s): Lu, Tom Y
• Application Number:
  US14/044,476
• Publication Number:
  US 20140099011A1
• Time in Patent Office: 937 Days
• US Class Current: 1/1
• CPC Class Codes: G06T 2207/10101 Optical tomography; Optical coherence tomography [OCT]
• CPC Class Codes: G06T 2207/20012 Locally adaptive
• CPC Class Codes: G06T 2207/30101 Blood vessel; Artery; Vein; Vascular
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 7/0012 Biomedical image inspection

Abstract

This invention generally relates to the removal of streaking artifacts and periodic noise from tomographic images. The method comprises obtaining an A-scan from an imaging data set. The A-scan having a signal and the signal defining an amplitude. Noise specific to the A-scan is estimated. The amplitude of the A-scan is scaled based on its specific estimated noise floor. In another aspect, a plurality of A-scans is obtained from an imaging data set. Each of the plurality of A-scans has a signal and the signal defines an amplitude. Noise specific to each A-scan of the plurality of A-scans is estimated. Each A-scan of the plurality of A-scans is scaled by the A-scan'"'"'s specific estimated noise floor.

Claims

1. A nontransitory computer-readable medium storing software code representing instructions that when executed by a computing system cause the computing system to perform a method of reducing noise in a tomographic image, the method comprising

obtaining an A-scan from an imaging data set, the A-scan having a signal and the signal defining an amplitude;

estimating a noise floor specific to the A-scan by performing a moving average across the A-scan to obtain a miminum average wherein the mininmum average comprises the estimated noise floor;

scaling the amplitude of the signal based on the estimated noise floor;

combining the scaled A-scans to form a B-scan; and

scan-converting the B-scan into a Cartesian coordinate system to create a final tomographic view of the image with reduced noise.

2. The computer-readable medium of claim 1, wherein the step of scaling comprises reducing the amplitude of the signal based on the estimated noise floor.

3. The computer-readable medium of claim 1, wherein the moving average comprises computing the arithmetic mean, geometric mean, harmonic mean or quadratic mean within a sliding window across the A-scan.

4. The computer-readable medium of claim 1, wherein the step of scaling further comprises adding a constant noise floor to the amplitude of the signal.

5. A nontransitory computer-readable medium storing software code representing instructions that when executed by a computing system cause the computing system to perform a method of reducing noise in a tomographic image, the method comprising

obtaining a plurality of A-scans from an imaging data set, each of the plurality of A-scans having a signal and the signal defining an amplitude;

estimating a noise floor specific to each of the plurality of A-scans;

scaling the amplitude of the signal in each of the plurality of A-scans based on the estimated specific noise floor for the corresponding A-scan;

combining the scaled A-scans to form a B-scan; and

scan-converting the B-scan into a Cartesian coordinate system to create a final tomographic view of the image with reduced noise.

6. The computer-readable system of claim 5, wherein the step of estimating comprises

averaging the amplitude of the signal at a plurality of pixels within a window of the A-scan.

7. The computer-readable medium of claim 5, wherein the step of estimating comprises

performing a moving average across the A-scan.

8. The computer-readable medium of claim 7, wherein the minimum average obtained from the performed moving average comprises the estimated noise floor.

9. The computer-readable medium of claim 5, wherein scaling comprises reducing the amplitude of the signal based on the estimated specific noise floor.

10. The computer-readable of claim 6, wherein the step of averaging comprises computing the arithmetic mean, geometric mean, harmonic mean or quadratic mean.

11. The computer-readable of claim 7, wherein the moving average comprises computing the arithmetic mean, geometric mean, harmonic mean or quadratic mean within a sliding window across the A-scan.

12. The computer-readable medium of claim 5, wherein the step of scaling further comprises adding a constant noise floor to the amplitude of the signal.

13. A system for imaging and reducing noise within a tomographic image, comprising:

a central processing unit (CPU); and

a storage device coupled to the CPU and having stored there information for configuring the CPU to;

obtain an A-scan from an imaging data set, the A-scan having a signal and the signal defining an amplitude;

estimate a noise floor specific to the A-scan by computing an arithmetic mean, geometric mean, harmonic mean or quadratic mean within a sliding window across the A-scan;

scale the amplitude of the signal based on the estimated noise;

combining the scaled A-scans to form a B-scan; and

scan-converting the B-scan into a Cartesian coordinate system to create a final tomographic view of the image with reduced noise.

14. The system of claim 13, wherein the minimum average obtained from the performed moving average comprises the estimated noise floor.

15. The system of claim 13, wherein scaling comprises reducing the amplitude of the signal based on the estimated noise floor.

16. The system of claim 13, wherein scaling further comprises adding a constant noise floor to the amplitude of the signal.