To solve the problem of sheets counting in the printing industry and so on, the count measurement method based on machine vision is proposed. Image acquisition system is built by using the latest high-resolution CMOS camera and megapixel, low distortion of the fixed focus lens. Aiming at the problem of detecting low contrast stacked sheets, a local histogram equalization algorithm and a linear enhancement based on bi-Gaussian second order are proposed. The algorithm is divided into the following parts. First, to improve the speed of the algorithm, only part of the image, which is obtained from image acquisition platform, is selected as processing area, and wavelet de-noising is performed. Second, the preprocessed image is enhanced by the local histogram equalization. Then, the detecting of the stacked sheets is acquired by using second-order derivative of bi-Gaussian and mean filter processing in the horizontal and vertical directions, respectively. Finally, the counting result can be acquired by the peak detection, and displayed in time. Experimental results show that the error rate of the count measurement method is less than 0.01% for the various types of sheets (including the 0.05 mm pure white sheets). It can also save a lot of manpower and material sources. Therefore, it deserves being promoted and used.