IMAGE PROCESSOR, IMAGE PROCESSING METHOD AND PROGRAM, AND IMAGING SYSTEM

• US 20140071227A1
• Filed: 09/10/2013
• Published: 03/13/2014
• Est. Priority Date: 09/11/2012
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Hirokazu Takenaka, Shusaku Takasu
• Inventors: TAKENAKA, Hirokazu, Terao, Noriyuki, Irino, Yoshiaki, Tanaka, Tomonori, Imae, Nozomi, Harada, Toru, Yamamoto, Hideaki, Sawaguchi, Satoshi, Bessho, Daisuke, Satoh, Hiroyuki, Shohara, Makoto, Masuda, Kensuke, Ito, Yoichi, Takasu, Shusaku
• Granted Patent: US 10,666,860 B2
• Time in Patent Office: Days
• US Class Current: 348/36
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

An image processor includes a first converter to convert input images into images in a different coordinate system from that of the input images according to first conversion data based on a projection model, a position detector to detect a connecting position of the images converted by the converter, a corrector to correct the first conversion data on the basis of a result of the detection by the position detector, and a data generator to generate second conversion data for image synthesis from the conversion data corrected by the corrector on the basis of coordinate conversion, the second conversion data defining the conversion of the input images.

Claims

1. An image processor comprising:

a first converter to convert input images into images in a different coordinate system from that of the input images according to first conversion data based on a projection model;

a position detector to detect a connecting position of the images converted by the converter;

a corrector to correct the first conversion data on the basis of a result of the detection by the position detector; and

a data generator to generate second conversion data for image synthesis from the conversion data corrected by the corrector on the basis of coordinate conversion, the second conversion data defining the conversion of the input images.

2. The image processor according to claim 1, wherein:

the first conversion data is such that an overlapping area between the input images is projected on near an equatorial line of a spherical surface; and

the coordinate conversion is a rotational coordinate conversion.

3. The image processor according to claim 1, further comprising:

a second converter to convert the input images into images in a different coordinate system from that of the input images according to the second conversion data; and

an image synthesizer to synthesize the images converted by the second converter and generate a synthetic image represented in a different coordinate system from that of the input images.

4. The image processor according to claim 1, wherein

the first conversion data is to define a projection from an input image represented in a plane coordinate system to an image represented in a polar coordinate system with at least two arguments.

5. The image processor according to claim 1, wherein:

the input images are captured with different lens systems; and

the first conversion data contains sets of data for correcting a distortion of the input images captured with the lens systems for projection.

6. The image processor according to claim 3, wherein:

the input images are captured with a lens system having an angle of view of larger than 180 degrees; and

the synthetic image is an omnidirectional image represented in a coordinate with at least two arguments.

7. An image processing method for a computer to execute the steps of:

receiving input images;

converting input images into images in a different coordinate system from that of the input images according to first conversion data based on a projection model;

detecting a connecting position of the images converted in the converting step;

correcting the first conversion data on the basis of a result of the detection by the detecting step; and

generating second conversion data for image synthesis from the conversion data corrected in the correcting step on the basis of coordinate conversion, the second conversion data defining the conversion of the input images.

8. The image processing method according to claim 7, wherein:

the detecting step includes finding, by pattern matching, a pixel connecting position of an overlapping area between a first image and a second image among the images converted in the converting step; and

the generating step includes finding, by rotational coordinate conversion, a coordinate value of a coordinate system of each of the converted images in association with a coordinate value of a coordinate system of a synthetic image, and acquiring a coordinate value of an input image associated with the found coordinate value.

9. The image processing method according to claim 7, further comprising the steps of:

converting the input images into images in a different coordinate system from that of the input images according to the second conversion data; and

synthesizing the images converted in the converting step and generating a synthetic image represented in a different coordinate system from that of the input images.

10. A non-transitory computer-readable storage medium storing a program for causing a computer to execute the steps of the image processing method according to claim 7.

11. An imaging system comprising:

an imaging element;

a converter to convert input images captured in different directions by the imaging element into images in a different coordinate system from that of the input images according to first conversion data based on a projection model;

a position detector to detect a connecting position of the images converted by the converter;

a corrector to correct the first conversion data on the basis of a result of the detection by the position detector; and

a data generator to generate second conversion data for image synthesis from the conversion data corrected by the corrector on the basis of coordinate conversion, the second conversion data defining the conversion of the input images.