Lamp Detection Device and Lamp Detection Method

• US 20180197026A1
• Filed: 07/08/2015
• Published: 07/12/2018
• Est. Priority Date: 07/08/2015
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Oki, Takahiko, Matsuo, Haruo, Yamanoi, Daiki
• Granted Patent: US 10,074,022 B2
• Time in Patent Office: Days
• CPC Class Codes: G06T 7/13 Edge detection
• CPC Class Codes: G06V 20/582 of traffic signs
• CPC Class Codes: G06V 20/584 of vehicle lights or traffic lights
• CPC Class Codes: G08G 1/09 Arrangements for giving variable traffic instructions railroad crossing signals B61L; reflectors E01F, G08B; indicating arrangements for variable information by selection or combination of individual elements G09F9/00
• CPC Class Codes: G08G 1/095 Traffic lights
• CPC Class Codes: G08G 1/09623 Systems involving the acquisition of information from passive traffic signs by means mounted on the vehicle G08G1/0967 takes precedence
• CPC Class Codes: H04N 23/00 Cameras or camera modules comprising electronic image sensors; Control thereof

Abstract

A lamp detection device detects an edge portion from a camera image, the edge portion having a luminance difference equal to or above a predetermined value, and generates a smoothed image by diminishing the luminance difference of the edge portion. Then, the lamp detection device extracts synchronized pixels from the smoothed image, the synchronized pixels having luminances varying synchronously with an alternating current cycle of power supplied to a lamp, and detects the lamp from the synchronized pixels.

Claims

1. A lamp detection device comprising:

an image shooting unit mounted on a vehicle and configured to acquire a camera image by shooting an image around the vehicle;

an edge detection circuit configured to detect an edge portion from the camera image, the edge portion having a luminance difference equal to or above a predetermined value;

an edge smoothing circuit configured to generate a smoothed image by diminishing the luminance difference between adjacent pixels at the edge portion;

a synchronized pixel extraction circuit configured to extract synchronized pixels from the smoothed image, the synchronized pixels having luminances varying synchronously with an alternating current cycle of power supplied to a lamp; and

a lamp detection circuit configured to detect the lamp from the synchronized pixels.

2. The lamp detection device according to claim 1, wherein the edge smoothing circuit diminishes the luminance difference only of edge subportions in the edge portion which are consecutive in a horizontal direction.

3. The lamp detection device according to claim 1, further comprising:

a vehicle behavior determination circuit configured to determine whether or not a velocity of a positional shift of the edge portion in the camera image is equal to or above a reference value, wherein

the synchronized pixel extraction circuit extracts the synchronized pixels having the luminances varying synchronously with the alternating current cycle of the power supplied to the lamp, from the smoothed image when the velocity of the positional shift of the edge portion is equal to or above the reference value, and

the synchronized pixel extraction circuit extracts the synchronized pixels having the luminances varying synchronously with the alternating current cycle of the power supplied to the lamp, from the camera image when the velocity of the positional shift of the edge portion is below the reference value.

4. A lamp detection method comprising:

acquiring a camera image by shooting an image around a vehicle while using an image shooting unit mounted on the vehicle;

detecting an edge portion from the camera image, the edge portion having a luminance difference equal to or above a predetermined value;

generating a smoothed image by diminishing the luminance difference between adjacent pixels at the edge portion;

extracting synchronized pixels from the smoothed image, the synchronized pixels having luminances varying synchronously with an alternating current cycle of power supplied to a lamp; and

detecting the lamp from the synchronized pixels.