图像增强方面的各种滤波算法（灰度线性变化，分段线性灰度变化，对数变化，直方图均衡化，图像平滑，在椒盐、高斯不同的噪声下，实现噪声的中值滤波，图像锐化）-Image enhancement (linear gray-scale changes in the terms of the various filtering algorithm, piecewise linear gray variation, logarithmic histogram equalization, image smoothing, salt and pepper, Gaussian noise, in the value of the noise filtering, image sharpening)