Stereo Disparity Filtering for Accurate Road Object Detection

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Solution Overview

Problem

Existing object detection devices struggle with high performance due to the complex shapes of roads and structures, leading to inaccurate obstacle detection.

Innovation Solution

A stereo camera system that generates a first disparity map, estimates the road surface shape, and removes unnecessary disparities based on the estimated shape to generate a second disparity map, enhancing object detection accuracy and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a stereo camera captures images of the entire road surface to enable object detection, then the detection coverage is improved, but false positives increase due to road structures and complex shapes

Engineering Contradiction:
Improvedetection coverageVSAvoiddetection accuracy
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent segments the road surface into multiple regions based on distance from the vehicle, applying different processing strategies to each region. The road surface is divided into a first region (closer to vehicle) and a second region (farther from vehicle), allowing selective disparity removal in the first region while preserving object detection capability in the second region.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different quality standards and processing methods to different parts of the road surface. In the first region where road structures cause false positives, aggressive disparity removal is applied. In the second region where objects need to be detected, the original disparity information is preserved with minimal processing.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If disparity information from the entire image is used for object detection, then detection completeness is improved, but detection accuracy deteriorates due to interference from road surface disparities

Engineering Contradiction:
Improvedetection completenessVSAvoiddetection accuracy
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent extracts and removes disparity information corresponding to the road surface from the disparity map. By identifying pixels that represent road surface disparities and removing them, the system eliminates the harmful interference while preserving disparity information for objects that needs to be detected.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the harmful road surface disparity information into a useful indicator by using it to identify and remove only the problematic disparities. The road surface disparity pattern is exploited to create a mask that selectively removes interfering information while preserving object information.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If the stereo camera system processes all disparity data to ensure comprehensive object detection, then detection thoroughness is improved, but processing complexity increases

Engineering Contradiction:
Improvedetection thoroughnessVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary processing to generate a road surface disparity map before the main object detection process. By pre-identifying and removing road surface disparities in advance, the subsequent object detection operates on simplified data with reduced complexity, while still achieving thorough detection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary processing step that creates a processed disparity map as a mediator between the raw stereo images and the final object detection. This intermediate representation separates road surface information from object information, simplifying the final detection process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS12354370B2Object detection device, object detection system, mobile object, and object detection method
Publication Date: 2025.07.08 KYOCERA CORP
  • US12354370B2 patent drawing
  • US12354370B2 patent drawing
  • US12354370B2 patent drawing

AI summary

An object detection device is configured to execute a first process, a second process, and an object detection process (third and fourth processes). The first process estimates a shape of a road surface in a real space on the basis of a first disparity map. The first disparity map is generated on the basis of an output of a stereo camera that captures an image including the road surface, and is a map in which a disparity obtained from the output of the stereo camera is associated with two-dimensional coordinates formed by a first direction corresponding to a horizontal direction of the image captured by the stereo camera and a second direction intersecting the first direction. The second process removes from the first disparity map a disparity for which a height from the road surface in the real space corresponds to a predetermined range on the basis of the estimated shape of the road surface to generate a second disparity map. The object detection process (third and fourth processes) detects an object on the basis of the second disparity map.