根据指纹的固有规律，提出了一套较完整的指纹图像预处理和特征提取算法。改进了指纹脊线频率求取算法和二值图像去孔噪声 算法，并提出了一种新的滤除指纹伪特征点的方法。通过对上百幅不同质量的指纹图像进行测试，获得了较好的效果。 关键词：指纹；预处理；特征提取-According to the inherent laws of fingerprints, a set of more complete fingerprint image pre-processing and feature extr

绘制密文和明文的频率直方图，然后可以观察密文的效果，从而可以简单测试加密的安全性- And a frequency histogram drawing ciphertext plaintext, the ciphertext and the effect can be observed, which can test the security of the encryption simple

对给定的多幅图片先进行训练分类，并进行频率分析，对于测试的图像与训练图像进行频率做差，求其最小的差值所对应的训练图像，就实现了图形识别。-For a given number of pictures first training classification, and frequency analysis, for the test image and training images to do the frequency difference, find the minimum differe