Recognition of visual patterns and characters are independent of position, size, and orientation in the visual field has been the goal of much recent research. The method presented in this paper meets all these condition. An off-line signature matchi

经典的二阶矩四阶矩信噪比估计，有不经过上采样、成型滤波和经过上采样、成型滤波的两种版本。加噪方式也分别用了matlab自带函数和自写两种版本。望大家参考。-Second Moment classic SNR estimation fourth moment, there is not through the sampling, the shaping filter and sampled, two versions of shaping filter. Plus noise mode were