Image processing apparatus

• US 20170032170A1
• Filed: 07/26/2016
• Published: 02/02/2017
• Est. Priority Date: 07/31/2015
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia, Inc.)
• Original Assignee: FotoNation Limited (Adeia, Inc.)
• Inventors: BAZRAFKAN, Shabab
• Granted Patent: US 10,303,916 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 40/1335 Combining adjacent partial images (e.g. slices) to create a composite input or reference pattern; Tracking a sweeping finger movement
• CPC Class Codes: G06V 40/1341 Sensing with light passing through the finger
• CPC Class Codes: G06V 40/14 Vascular patterns

Abstract

An image processing apparatus comprises a set of infra-red (IR) sources surrounding an image capture sensor and a processor operatively coupled to said IR sources and said image capture sensor. The processor being arranged to acquire from the sensor a succession of images, each illuminated with a different combination of the IR sources. The processor is further arranged to combine component images corresponding to the succession of images by selecting a median value for corresponding pixel locations of the component images as a pixel value for the combined image.

Claims

1. An image processing apparatus comprising a set of infra-red (IR) sources surrounding an image capture sensor and a processor operatively coupled to said IR sources and said image capture sensor, the processor being arranged to acquire from the sensor a succession of images, each illuminated with a different combination of the IR sources, the processor being further arranged to combine component images corresponding to the succession of images by selecting a median value for corresponding pixel locations of said component images as a pixel value for the combined image.

2. An image processing apparatus as claimed in claim 1 wherein said processor is arranged to high-pass filter each of said succession of images to compensate for an illumination gradient across said succession of images from respective illuminating light sources.

3. An image processing apparatus as claimed in claim 2 wherein said processor is further arranged to normalise said high-pass filtered images so that pixel values of said component images are in the range [0,1].

4. An image processing apparatus as claimed in claim 1 wherein said processor is further arranged to apply a Gabor filter bank to said combined image to provide a finger vein map.

5. An image processing apparatus as claimed in claim 1 wherein said processor is arranged to perform 3D temporal median filtering to combine said component images into said combined image.

6. An image processing apparatus as claimed in claim 1 wherein said processor comprises a processor for a consumer electronic device.

7. An image processing apparatus as claimed in claim 1 wherein said processor comprises at least one dedicated processing module within a consumer electronic device.

8. An image processing apparatus as claimed in claim 1 wherein said apparatus comprises 12>

N>

6 light sources.

9. An image processing apparatus as claimed in claim 8 wherein said processor is arranged to capture a succession of N images, each lit by a respective light source.

10. An image processing apparatus as claimed in claim 1 wherein said processor is further arranged to spatially align said succession of images.

11. An image processing apparatus as claimed in claim 1 wherein each light source comprises an NIR LED.

12. An image processing apparatus as claimed in claim 1 further comprising an image store for at least temporarily storing said succession of images and/or said combined image.

13. An image processing apparatus as claimed in claim 1 wherein the processor is further arranged to combine respective sets of component images corresponding to plural sets of acquired images by selecting a median value for corresponding pixel locations of said component images as a pixel value for a respective intermediate combined image, the processor being arranged to combine said intermediate combined images by selecting a median value for corresponding pixel locations of said intermediate combined images as a pixel value for a final combined image.

14. A consumer electronic device incorporating the image processing apparatus according to claim 1 and being arranged to employ said image processing apparatus to register a user with an application and/or said device and to authenticate a user to an application and/or said device.