Method for recognizing a liquid level using temporal variation in the distribution of the pixel concentration in images, and apparatus for recognizing a liquid level using same

The present invention relates to a method for recognizing a liquid level using temporal variation in the distribution of the pixel concentration in images, and to an apparatus for recognizing a liquid level using same. The method comprises: performing gray-image processing on the image captured so as to contain a liquid level and digitizing each pixel distributed in the X-axis direction and the Y-axis direction in accordance with the concentration of the pixel; extracting only the image for the X-axis direction scale zone on a watermark; adding numerical values of pixels in the Y-axis direction in the extracted image to generate histogram data for the Y-axis direction of pixels; comparing histogram data of images captured before and after a certain time; determining whether or not a difference higher than a preset incremental value occurs in the histogram data; and recognizing, as a liquid level, the Y-axis direction position (height) of the pixel from which the difference higher thanthe preset incremental va