Single-pointer meter reading method based on machine vision

Abstract

The invention relates to a single-pointer meter reading method based on machine vision. The method comprises the steps of collecting a template map and modeling and performing feature detection on a template map dial area, a step of performing feature detection on a meter image to be the recognized, completing the dial area positioning in the meter image to be the recognized by using the feature matching technology and calibrating a dial area to be recognized as a template map state, a step of processing the calibrated dial area map, a step of obtaining a pointer area by using a pointer-basedfeature search method, a step of carrying out shadow removal on the pointer area, a step of obtaining a pointer single pixel boundary by using a morphology method, completing adaptive pointer boundarylinear detection, and obtaining a pointer straight line by an angular bisector, a step of completing pointer direction judgment by using a projection method, and completing meter reading by using anangular method. According to the method, the information needed by pointer-type meter recognition can be reduced, the method can be adapted to the conditions of pointer breakage and pointer and text stickiness in an image, the method is not interfered by a pointer shadow, and the method has high accuracy and stability.

Description

technical field [0001] The invention belongs to the technical field of computer image processing, in particular to a single-pointer meter reading method based on machine vision. Background technique [0002] In the power industry, petroleum system, automotive electronics and other fields, pointer instruments are equipped, such as pressure gauges, thermometers, oil level gauges, counters, etc. The traditional manual reading method is inefficient, and long-term reading will cause visual fatigue, resulting in reduced accuracy. In addition, some meters are installed too high for direct manual readings. With the development of computer vision and image processing technology, more and more methods of instrument reading based on image processing have been proposed. [0003] Patent CN201610830466.3 proposes an automatic reading method for electric pointer instruments. First, the collected instrument images are preprocessed, and the dial positioning is completed by using the color ...

AI Technical Summary

Problems solved by technology

This method uses feature matching for the positioning of the dial, which is still applicable when the dial rotates and the illumination changes, which improves the versatility of the algorithm. However, the SIFT feature detection speed is too slow, and it cannot be used in some occasions where the inspection time is limited. Be applicable

In addition, there are some problems in directly detecting the straight line within the range of the scale: first, some interference causes the pointer to break in the image; second, the shadow of the pointer will appear due to the influence of ambient light; These issues need to be fully considered in order to improve the practicability and stability of the algorithm

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