Gray level image contrast drawing method and device

The invention relates to a gray level image contrast drawing technology, in particular to a gray level image contrast drawing method and device, and is applied to the fields of gray level image preprocessing and the like. The gray level image contrast drawing method comprises the following steps: reading image data; performing gray level histogram statistics and calculating the mean value of the gray levels according to the gray levels of pixels of an image; finding out a pixel point of which the gray level is higher than an upper threshold or lower than a lower threshold, and filling the pixel point with the mean value of the gray levels; performing gray linear transformation on the pixel point to obtain a contrast drawn pixel gray level. The gray level image contrast drawing method and device are remarkable in drawing effect, and high in real-time performance.