Water level gauge positioning and water level measuring method based on image processing

Abstract

The invention discloses a water level gauge positioning and water level measuring method based on image processing, wherein the water level gauge positioning method comprises the following steps: calculating the longitudinal inclination angle of a mark rod main body of a pre-extracted water level gauge image; obtaining a water level gauge main body image after inclination correction by adopting arotation correction technology according to the longitudinal inclination angle of the mark rod main body; correcting perspective distortion by using a calibration point technology for the main image of the water level gauge after inclination correction; using a projection method to carry out adjacent pixel repair on a missing value part in the distortion-corrected image; carrying out accurate target clipping on the repaired image according to the coordinate equation of the left and right dividing lines; the starting position of the water level gauge and the position of the boundary line with the water surface are identified and the main body position of the water level gauge is cut according to the starting position and the position of the boundary line with the water surface. According tothe water level gauge positioning and water level measuring method based on image processing, the distortion correction is carried out on the water level gauge image after the inclination correction,the distortion problem caused by the non-parallel lateral boundary of the target caused by the viewpoint selection angle of the image is solved, and the precision of target extraction is improved.

Description

technical field [0001] The invention relates to the fields of computer vision, neural network and image processing, in particular to a method for extracting a real-time water level scale and detecting water level based on image processing. Background technique [0002] The existing water level monitoring has a large initial investment in infrastructure, cannot adapt to complex background environments, requires high precision equipment installation, requires frequent maintenance, and manual readings are not advisable in bad weather environments; the water level measurement scale in the traditional intelligent water level recognition system based on image processing The positioning method does not eliminate the reading interference caused by strong light and water surface refraction, and does not take into account the viewing point selection of the front-end video input device (that is, the viewing angle is selected at the top or bottom of the scale, resulting in non-parallel l...

AI Technical Summary

Problems solved by technology

[0002] The existing water level monitoring has a large initial investment in infrastructure, cannot adapt to complex background environments, requires high precision equipment installation, requires frequent maintenance, and manual readings are not advisable in bad weather environments; the water level measurement scale in the traditional intelligent water level recognition system based on image processing The positioning method does not eliminate the reading interference caused by strong light and water surface refraction, and does not take into account the viewing point selection of the front-end video input device (that is, the viewing angle is selected at the top or bottom of the scale, resulting in non-parallel lateral borders of the water level scale and distortion, which will affect subsequent water level extraction. In addition, due to the lack of value area in the corrected image after tilt correction, if the tilt angle is too large, direct cropping will lead to the loss of the effective area of ​​the scale; on the other hand, the water level measurement in the traditional intelligent water level recognition system based on image processing Method The determination of the upper and lower boundaries of the main body of the water level scale is obtained by approximating to the "non-zero area", but the positioning of the "non-zero area" is very vague

This method does not take into account the interference factors of the complex hydrological background, such as reflections, refraction of the scale below the water surface, or the background of the scale is a complex natural environment, its accuracy will be greatly weakened or even invalid

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