STEREO CAMERA APPARATUS AND METHOD OF OBTAINING IMAGE

• US 20120236124A1
• Filed: 03/06/2012
• Published: 09/20/2012
• Est. Priority Date: 03/18/2011
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: AOKI, Shin
• Granted Patent: US 8,922,626 B2
• Time in Patent Office: Days
• US Class Current: 348/47
• CPC Class Codes: G01C 3/085 with electronic parallax measurement
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals
• CPC Class Codes: H04N 25/40 Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled

Abstract

A stereo camera apparatus for obtaining distance information of an object includes a camera unit that includes a left image sensor and a right image sensor respectively obtaining a left-side image and a right-side image, each being composed of a frame including plural pixels of plural rows and plural columns, the left image sensor and the right image sensor sequentially exposing the pixels of the rows from upper to lower in the frames, respectively; a shift amount detection unit that detects a relative positional shift amount in the vertical direction between a left-side image and a right-side image; and a timing control unit that changes the starting time of exposing the frame by the left image sensor or by the right image sensor based on the positional shift amount in the vertical direction detected by the shift amount detection unit.

Claims

1. A stereo camera apparatus for obtaining distance information of an object, comprising:

a camera unit that includes a left image sensor and a right image sensor which are positioned parallel to each other to respectively obtain a left-side image and a right-side image, each of the images being composed of a frame including plural pixels of plural rows and plural columns, the left image sensor and the right image sensor sequentially exposing the pixels of the rows from an upper row to a lower row in the frames, respectively;

a shift amount detection unit that detects a relative positional shift amount in the vertical direction between a left-side image and a right-side image respectively obtained by the left image sensor and the right image sensor; and

a timing control unit that changes a starting time of exposing the frame by the left image sensor or by the right image sensor based on the positional shift amount in the vertical direction detected by the shift amount detection unit.

2. The stereo camera apparatus according to claim 1,

wherein the timing control unit delays the starting time of exposing the frame by the left image sensor or by the right image sensor for which the relative position of the obtained image with respect to the image obtained by the opposite image sensor is shifted upward, for a time corresponding to the vertical shift amount.

3. The stereo camera apparatus according to claim 1, further comprising:

a correction unit that shifts the positions of the pixels of a left-side image obtained by the left image sensor or a right-side image obtained by the right image sensor based on the positional shift amount in the vertical direction detected by the shift amount detection unit.

4. The stereo camera apparatus according to claim 3,

wherein the shift amount detection unit detects a relative positional shift amount in the horizontal direction between the left-side image and the right-side image respectively obtained by the left image sensor and the right image sensor, and

the correction unit shifts the positions of the pixels of the left-side image obtained by the left image sensor or the right-side image obtained by the right image sensor for a distance equivalent to a difference between the relative positional shift amount in the horizontal direction detected by the shift amount detection unit and a predetermined appropriate positional shift amount.

5. The stereo camera apparatus according to claim 1,

wherein the shift amount detection unit

obtains a first reference image and a second reference image respectively obtained by the left image sensor and the right image sensor, each of the reference images including a marker object fixed to be within a field of vision of the left image sensor and the right image sensor, and

detects the relative positional shift amount in the vertical direction based on the positions of the marker object in the first reference image and in the second reference image.

6. The stereo camera apparatus according to claim 1,

wherein the left image sensor and the right image sensor are rolling shutters.

7. The stereo camera apparatus according to claim 1,

wherein the timing control unit delays the starting time of exposing the frame by the left image sensor or by the right image sensor so that the left image sensor and the right image sensor expose an image of a same object at the same time.

8. A method of obtaining an image obtained by a stereo camera apparatus including a left image sensor and a right image sensor, each of the sensors sequentially exposing pixels of rows from an upper row to a lower row in a frame, comprising:

detecting a relative positional shift amount in a vertical direction between a left-side image and a right-side image respectively obtained by the left image sensor and the right image sensor; and

changing a starting time of exposing the frame by the left image sensor or by the right image sensor based on the positional shift amount in the vertical direction detected in the detecting the relative positional shift amount in the vertical direction.

9. The method of obtaining an image according to claim 8, further comprising:

shifting the positions of the pixels of a left-side image obtained by the left image sensor or a right-side image obtained by the right image sensor based on the positional shift amount in the vertical direction detected in the detecting the relative positional shift amount in the vertical direction.

10. The method of obtaining an image according to claim 8,

wherein in changing the starting time of exposing the frame, the starting time of exposing the frame by the left image sensor or by the right image sensor is delayed so that the left image sensor and the right image sensor expose respective images of a same object at the same time.