Attachable matter detection apparatus and attachable matter detection method

• US 10,552,706 B2
• Filed: 10/03/2017
• Issued: 02/04/2020
• Est. Priority Date: 10/24/2016
• Status: Active Grant

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation)
• Inventors: Ikeda, Nobuhisa, Kono, Takashi, Asayama, Nobunori, Yamamoto, Daisuke, Tani, Yasushi, Hashimoto, Junji
• Primary Examiner(s): Lee, John W
• Application Number:
  US15/723,588
• Publication Number:
  US 20180114089A1
• Time in Patent Office: 854 Days
• CPC Class Codes: B60R 1/00 Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
• CPC Class Codes: B60R 2300/30 characterised by the type of image processing
• CPC Class Codes: B60R 2300/303 using joined images, e.g. multiple camera images
• CPC Class Codes: B60R 2300/305 merging camera image with lines or icons
• CPC Class Codes: G06V 10/22 by selection of a specific region containing or referencing a pattern; Locating or processing of specific regions to guide the detection or recognition
• CPC Class Codes: G06V 10/507 Summing image-intensity values; Histogram projection analysis
• CPC Class Codes: G06V 10/758 Involving statistics of pixels or of feature values, e.g. histogram matching

Abstract

An attachable matter detection apparatus according to an embodiment includes an acquirement unit, a creation unit, and a determination unit. The acquirement unit acquires a determination target area of an attachable matter from a photographic image. The creation unit creates histograms of at least an edge intensity, luminance, and saturation for the determination target area acquired by the acquirement unit. The determination unit determines whether or not the attachable matter exists in the determination target area on the basis of a ratio of frequency of each grade in each of the histograms created by the creation unit.

Claims

1. An attachable matter detection apparatus comprising:

a memory that stores therein condition information; and

a processor operatively connected to the memory, the processor being programmed to;

cause an imaging device, which is mounted on a vehicle, to capture a photographic image of a circumference of the vehicle, the imaging device including an image sensor;

acquire, as a determination target area, a detection area of the photographic image in which an attachable matter to the imaging device is estimated to be present by executing a predetermined detection algorithm on the photographic image captured by the imaging device;

create, for the acquired determination target area, a histogram of an edge intensity, a histogram of luminance, and a histogram of saturation, each of the histograms including a plurality of grades, and each of the grades including a corresponding frequency,

wherein the condition information stored in the memory includes an exclusion condition obtained by combining (i) ratios between the grades of the edge intensity, (ii) ratios between the grades of the luminance, and (iii) ratios between the grades of the saturation, the exclusion condition not being suitable for characteristics of an attachable matter to the imaging device;

compare, with the condition information stored in the memory, a combination of ratios between the grades of the edge intensity, the luminance, and the saturation of the acquired determination target area;

when the combination satisfies the exclusion condition, determine that the attachable matter does not exist on the imaging device corresponding to the determination target area; and

when the combination does not satisfy the exclusion condition, determine that the attachable matter exists on the imaging device corresponding to the determination target area.

2. The attachable matter detection apparatus according to claim 1, wherein

each of the created histograms includes at least three grades including “

low,”

“

middle,” and

“

high”

.

3. The attachable matter detection apparatus according to claim 1, wherein the processor is further programmed to:

determine whether or not the attachable matter exists based on a change amount of at least one of the created histograms between a current frame and a previous frame.

4. The attachable matter detection apparatus according to claim 3, wherein the processor is further programmed to:

acquire each of a plurality of partitioned areas set for the photographic image as the determination target area; and

determine that the attachable matter exists with respect to a partitioned area in which the change amount satisfies a predetermined detection condition.

5. The attachable matter detection apparatus according to claim 4, wherein the detection condition is able to be set for each partitioned area.

6. The attachable matter detection apparatus according to claim 4, wherein the processor is further programmed to:

adjust the detection condition when a predetermined trigger that is suitable for adjustment of the detection condition is generated;

adjust the detection condition to be reinforced when the determination target area is positioned in a lower region of the photographic image.

7. The attachable matter detection apparatus according to claim 1, wherein the processor is further programmed to:

enlarge or reduce a size of the determination target area to match a reference size when the histograms are created.

8. An attachable matter detection method comprising:

causing an imaging device, which is mounted on a vehicle, to capture a photographic image of a circumference of the vehicle, the imaging device including an image sensor;

acquiring, as a determination target area, a detection area of the photographic image in which an attachable matter to the imaging device is estimated to be present by executing a predetermined detection algorithm on the photographic image captured by the imaging device;

creating, for the acquired determination target area, a histogram of an edge intensity, a histogram of luminance, and a histogram of saturation, each of the histograms including a plurality of grades, and each of the grades including a corresponding frequency;

compare, with condition information stored in a memory, a combination of ratios between the grades of the edge intensity, the luminance, and the saturation of the acquired determination target area, wherein the condition information stored in the memory includes an exclusion condition obtained by combining (i) ratios between the grades of the edge intensity, (ii) ratios between the grades of the luminance, and (iii) ratios between the grades of the saturation, the exclusion condition not being suitable for characteristics of an attachable matter to the imaging device;

when the combination satisfies the exclusion condition, determining that the attachable matter does not exist on the imaging device corresponding to the determination target area; and

when the combination does not satisfy the exclusion condition, determining that the attachable matter exists on the imaging device corresponding to the determination target area.