JP-7856882-B2 - Image processing device, image processing system, and image processing method

JP7856882B2JP 7856882 B2JP7856882 B2JP 7856882B2JP-7856882-B2

Inventors

服部公祐

Assignees

日新電機株式会社

Dates

Publication Date: 20260512
Application Date: 20210915

Claims (10)

A cropping area size calculation unit calculates the size of the cropping area based on the license plate position coordinates in the captured image of a moving vehicle, The system includes a cropping processing unit that extracts an image from the captured image for determining the type of automobile, according to the cropping area size calculated by the cropping area size calculation unit, The cropping area size calculation unit calculates the cropping area size when the height coordinates of the license plate position coordinates coincide with the height coordinates of the reference license plate position coordinates that serve as the reference when the cropping processing unit crops the image.
A cropping area size calculation unit calculates the size of the cropping area based on the license plate position coordinates in the captured image of a moving vehicle, The system includes a cropping processing unit that extracts an image from the captured image for determining the type of automobile, according to the cropping area size calculated by the cropping area size calculation unit, The image processing apparatus calculates the cropping area size L × L by the following equation (Equation 1a), where the Y-coordinate is the height coordinate of the license plate position, α is the vertical size of the captured image, β is the size of the cropping area when the Y-coordinate is at its maximum, and γ is the size of the cropping area when the Y-coordinate is at its minimum. L=(β-γ)×y/α+γ...(Formula 1a)
The image processing apparatus further includes a configuration file that defines at least the reference license plate position coordinates, α, β, and γ which serve as the reference when the cropping processing unit crops an image , The image processing apparatus according to claim 2, wherein the cropping area size calculation unit calculates the cropping area size by referring to the setting file.
The image processing apparatus according to claim 3, wherein the configuration file defines the reference license plate position coordinates, α, β, and γ so as not to include the background image of the vehicle.
The image processing apparatus according to claim 3 or 4, wherein the cropping area size calculation unit calculates the cropping area size L × L for each Y coordinate of the license plate position coordinate and defines it in the setting file as a table showing the relationship between the Y coordinate of the license plate position coordinate and the cropping area size L × L.
The image processing apparatus according to any one of claims 1 to 5, wherein the cropping processing unit crops the image such that the vertical and horizontal dimensions of the cropping area size calculated by the cropping area size calculation unit, based on the license plate position coordinates, are in a predetermined ratio.
An image processing system comprising an imaging device and an image processing device, The aforementioned imaging device includes an imaging unit that photographs a moving vehicle, It includes a position coordinate detection unit that detects the position coordinates of the vehicle's license plate from the captured image taken by the imaging unit, The image processing apparatus includes a cropping area size calculation unit that calculates the cropping area size based on the license plate position coordinates detected by the position coordinate detection unit, Includes a cropping processing unit that crops an image from the captured image for determining the type of vehicle, according to the cropping area size calculated by the cropping area size calculation unit, The cropping area size calculation unit calculates the cropping area size when the height coordinates of the license plate position coordinates coincide with the height coordinates of the reference license plate position coordinates that serve as the reference when the cropping processing unit crops the image.
An image processing system comprising an imaging device and an image processing device, The aforementioned imaging device includes an imaging unit that photographs a moving vehicle, It includes a position coordinate detection unit that detects the position coordinates of the vehicle's license plate from the captured image taken by the imaging unit, The image processing apparatus includes a cropping area size calculation unit that calculates the cropping area size based on the license plate position coordinates detected by the position coordinate detection unit, Includes a cropping processing unit that crops an image from the captured image for determining the type of vehicle, according to the cropping area size calculated by the cropping area size calculation unit, The image processing system calculates the cropping area size L × L using the following formula (Formula 1a), where the Y-coordinate is the height coordinate of the license plate position, α is the vertical size of the captured image, β is the size of the cropping area when the Y-coordinate is at its maximum, and γ is the size of the cropping area when the Y-coordinate is at its minimum. L=(β-γ)×y/α+γ...(Formula 1a)
A process of calculating the size of the cropping area based on the license plate position coordinates in an image taken of a moving vehicle, The process includes the step of extracting an image from the captured image for determining the type of vehicle, according to the calculated size of the extraction region, An image processing method in which, in the step of calculating the size of the cropped area, the size of the cropped area is calculated when the height coordinates of the license plate position coordinates and the height coordinates of the reference license plate position coordinates that serve as the basis for cropping the image coincide.
A process of calculating the size of the cropping area based on the license plate position coordinates in an image taken of a moving vehicle, The process includes the step of extracting an image from the captured image for determining the type of vehicle, according to the calculated size of the extraction region, An image processing method in which, in the step of calculating the size of the cropped area, the size L × L is calculated by the following equation (Equation 1a), where α is the vertical size of the captured image, β is the size of the cropped area when the Y coordinate is at its maximum, and γ is the size of the cropped area when the Y coordinate is at its minimum. L=(β-γ)×y/α+γ...(Formula 1a)

Description

This invention relates to an image processing apparatus, an image processing system, and an image processing method. Various technologies for identifying the type of automobile have been developed over time. Related technologies include the inventions disclosed in Patent Documents 1 and 2 below. Patent Document 1 relates to a vehicle type matching system. The vehicle type matching system comprises an in-vehicle unit that outputs first vehicle type data, which is visual information; a vehicle type identification device that outputs second vehicle type data of a vehicle equipped with the in-vehicle unit; a matching device that compares the first vehicle type data and the second vehicle type data; and a management center that notifies the vehicle owner of the matching result when the vehicle types indicated by the first and second vehicle type data do not match. Patent Document 2 relates to a technology for determining the type of vehicle of a passing vehicle. The acquisition unit acquires a first image of the vehicle captured by one of multiple imaging devices, and a second image captured by the imaging device at a different time than the first image. The detection unit detects a first image of the vehicle from the first image and a second image of the vehicle from the second image. The first discrimination unit determines the type of vehicle based on the first image and discrimination criteria. The second discrimination unit determines the type of vehicle based on the second image and discrimination criteria. The integrated discrimination unit integrates the discrimination results of the first discrimination unit and the second discrimination unit to determine the type of vehicle. Japanese Patent Publication No. 2003-281687 (Published October 3, 2003)Japanese Patent Publication No. 2018-190082 (Published November 29, 2018) This is a block diagram showing the schematic configuration of an image processing system according to one embodiment of the present invention.This is a diagram illustrating the coordinates of the license plate position.This table shows the relationship between the Y-coordinate of the license plate position and the size of the cropping area.This figure shows an example of a cutting area.This figure shows an example of an image extracted by the extraction processing unit.This is a flowchart illustrating the processing procedure of an image processing apparatus according to one embodiment of the present invention. (Example configuration of image processing system 100) Figure 1 is a block diagram showing a schematic configuration of an image processing system 100 according to one embodiment of the present invention. The image processing system 100 comprises an imaging device 1 and an image processing device 2. This image processing system 100 can photograph automobiles traveling on a road and extract images for identifying the vehicle type. Alternatively, the image processing system 100 may photograph automobiles entering and exiting a parking lot and extract images for identifying the vehicle type. Note that "vehicle type" refers not only to the type of vehicle, such as trucks or light vehicles, but also to the name of the automobile. Therefore, the image processing device 2 extracts images in a way that allows for the identification of the name of the automobile. The imaging device 1 includes an imaging unit 11 and a position coordinate detection unit 12. The imaging unit 11 is composed of a camera or the like and captures an image of a moving vehicle. The imaging unit 11 is installed, for example, at a height of about 6 meters and captures the front (front section) of the moving vehicle from an oblique angle above. The imaging unit 11 may also be configured to capture the rear of the moving vehicle. The position coordinate detection unit 12 extracts the license plate image from the captured image of the front of the vehicle and detects the license plate position coordinates. This detection of license plate position coordinates will be explained using Figure 2. Figure 2 illustrates the license plate position coordinates. As shown in Figure 2, the license plate has lines indicating the regional name "Kyoto" and classification number "xxx," and lines indicating the purpose "a" and serial number "xx-xx." The position coordinate detection unit 12 detects the coordinates of point P, which is located between the lines indicating the regional name and classification number and the lines indicating the purpose and serial number, and is in the center of the width, as the license plate position coordinates, and outputs them to the image processing device 2. Note that the license plate position coordinates are not limited to these; other coordinates based on the license plate may also be used. As shown in Figure 2, if the length from point P to the left edge of the license plate is W L and the length from point P to the right edge of the license plate is WR , the position coordinate detection unit 12