Double-pointer instrument number reading method based on machine vision

Abstract

The invention relates to a double-pointer instrument number reading method based on machine vision. The method comprises the following steps of acquiring a template picture and performing modeling, performing characteristic detection on a to-be-identified instrument picture, and acquiring target area positioning in the to-be-identified instrument picture by means of characteristic matching; intercepting a dial area graph from the target area; preprocessing the dial area graph, searching a reading number pointer area and eliminating a shadow; searching a reading number pointer line by means ofthe reading number pointer area; acquiring a threshold pointer image according to a pointer color characteristic which is stored in modeling; preprocessing the threshold pointer image, searching a threshold point area and eliminating the shadow; searching a threshold pointer line by means of the threshold point area; determining directions of two pointers by means of a projection method; and finishing number reading of two pointers by means of an angle method. According to the method of the invention, the target area can be accurately positioned on the condition of dial rotating and illumination changing; the method can be adapted with the conditions of pointer breaking and adhesion between the pointer and texts in the image; and furthermore the method is not interfered by the pointer shallow, thereby realizing relatively high accuracy and stability.

Description

technical field

[0001] The invention belongs to the technical field of computer image processing, and relates to a machine vision-based two-pointer meter reading method. Background technique

[0002] In the fields of power systems, industrial measurement systems, etc., some equipment is equipped with a two-pointer instrument to characterize the state of the equipment. A two-pointer instrument refers to an instrument with two pointers, one of which is used as a reading pointer to read the current value of the meter, and the other pointer is used as a threshold pointer to warn the upper or lower limit of the safe value of the meter. When the reading pointer exceeds the threshold pointer, it means that the current equipment status is abnormal, and the staff needs to make corresponding treatment.

[0003] At present, the reading method of the two-pointer instrument is mainly the manual reading method, which is inefficient, and the long-term reading will cause visual fatigue, re...

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