说明：  答题卡自动阅卷系统通过获取答题卡图像作为系统输入，并通过计算机处理、自动识别填图标记，存入数据库完成阅卷。 但是答题卡在运输和使用过程中，容易受到设备、环境等因素的影响，使得图像质量在一定程度上有所下降，影响了自动阅卷的准确率，甚至导致无法正常阅卷，因此要对答题卡图像进行一系列的预处理，滤去干扰、噪声，做几何校正（有的答题卡可能是倒着的），彩色校正等，并进行二值化处理。
(Answer card automatic marking system takes the image of answer card as the input of the system, and through computer processing, automatic identification of filling marks, and storage in the database to complete marking. But in the process of transportation and use, Answer Card is vulnerable to the influence of equipment, environment and other factors, which makes the image quality decline to a certain extent, affects the accuracy of automatic marking, and even leads to the failure of normal marking. Therefore, a series of preprocessing of Answer Card image is needed to filter out interference and noise, and make geometric correction (some of the Answer Cards may be inverted). Color correction and binarization.)