A binarization algorithm for digital meter image based on gray-scale morphology

Through analyzing and researching the characteristic of the digital meter image and the effect of the top-hat transform and bottom-hat transform, a kind of binarization algorithm for digital meter image based on gray-scale morphology is presented. A gray-scale digital meter image is processed by top-hat transform and bottom-hat transform separately after a specifically kind of structuring element is chosen. And then, a contrast enhancement image is achieved by subtracting the image obtained by bottom-hat transform from the original image plus the image obtained by Top-hat transform. The binarization procedure is accomplished after threshold value is acquired by the adaptive threshold method. The Experimental results show the effectiveness and robustness for digital meter image with uneven illumination of the algorithm.