Image processing device and image processing method

Patent metadata

Field	Value
Publication number	US-2016267348-A1
Application number	US-201415032195-A
Country	US
Kind code	A1
Filing date	Nov 17, 2014
Priority date	Dec 16, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

A polarization image acquisition unit ( 11 ) acquires polarization images of three or more polarization directions. A feature quantity computation unit ( 15 ) computes image feature quantities on the basis of the acquired polarization images. For example, the luminance of each polarization image is normalized for each pixel, and the normalized luminance of the polarization image is used as the image feature quantity. The luminance of the polarization image changes according to the surface shape of an object. Thus, the image feature quantities computed on the basis of the polarization images are feature quantities corresponding to the surface shape of the object. Image processing, for example, image recognition, feature point detection, feature point matching, or the like, can be performed on the basis of the surface shape of the object using such image feature quantities.

First claim

1 . An image processing device comprising:
a polarization image acquisition unit configured to acquire a polarization image; and an image processing unit configured to perform image processing using an image feature quantity computed on the basis of the polarization image acquired by the polarization image acquisition unit.

2 . The image processing device according to claim 1 , wherein the image processing unit performs a process of recognizing an object in the polarization image using the image feature quantity as the image processing.

3 . The image processing device according to claim 1 , wherein the image processing unit performs a process of detecting a feature point of an object in the polarization image using the image feature quantity as the image processing.

4 . The image processing device according to claim 1 , wherein the image processing unit performs a matching process with a feature point of an object in the polarization image using the image feature quantity as the image processing.

5 . The image processing device according to claim 1 , further comprising:
a feature quantity computation unit configured to compute an image feature quantity using the polarization image acquired by the polarization image acquisition unit.

6 . The image processing device according to claim 5 , wherein the feature quantity computation unit computes the image feature quantity using luminance of the polarization image for each pixel.

7 . The image processing device according to claim 6 , wherein the feature quantity computation unit normalizes the luminance and designates the normalized luminance for each polarization direction as the image feature quantity.

8 . The image processing device according to claim 5 , wherein the feature quantity computation unit uses a feature quantity of a pixel positioned near a feature quantity computation target pixel in computation of the image feature quantity.

9 . The image processing device according to claim 5 , wherein the feature quantity computation unit computes the image feature quantity on the basis of a reflection characteristic of an object in the polarization image.

10 . The image processing device according to claim 9 , wherein the feature quantity computation unit computes the image feature quantity on the basis of a ratio between a diffuse reflection component and a specular reflection component.

11 . The image processing device according to claim 5 , wherein the feature quantity computation unit computes the image feature quantity on the basis of a refractive index of an object in the polarization image.

12 . The image processing device according to claim 5 , further comprising:
a non-polarization image feature quantity computation unit configured to generate a non-polarization image from the polarization image acquired by the polarization image acquisition unit and compute a feature quantity on the basis of the non-polarization image, wherein the feature quantity computation unit computes the image feature quantity using information determined when the non-polarization image feature quantity computation unit computes the feature quantity.

13 . The image processing device according to claim 12 ,
wherein the non-polarization image feature quantity computation unit computes the feature quantity on the basis of gradient information of the non-polarization image, and wherein the feature quantity computation unit computes the image feature quantity using information based on a gradient strength and a gradient direction determined when the non-polarization image feature quantity computation unit computes the feature quantity.

14 . The image processing device according to claim 12 , wherein the feature quantity computation unit includes the feature quantity computed by the non-polarization image feature quantity computation unit in the image feature quantity computed using the polarization image.

15 . The image processing device according to claim 1 , wherein the polarization image acquisition unit acquires a polarization image of three or more polarization directions.

16 . An image processing method comprising the steps of:
acquiring, by a polarization image acquisition unit, a polarization image; and performing, by an image processing unit, image processing using an image feature quantity computed on the basis of the polarization image acquired by the polarization image acquisition unit.

Assignees

• Sony Corp

Inventors

• Kondo Yuhi

Classifications

• G06V10/145 Primary

  Illumination specially adapted for pattern recognition, e.g. using gratings · CPC title

• G06V10/462

  Salient features, e.g. scale invariant feature transforms [SIFT] · CPC title

• G06T2207/10141

  Special mode during image acquisition · CPC title

• G02B5/3025

  Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence) · CPC title

• G02B27/286

  for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34) · CPC title