1.Bilateral Image Filter c++ fast

2.Base on Bilateral Filter to enhance iamge detail.

3.this is an implementation of Kevin Chen's bilateral grid filter on the IOS,use Bilateral Grid to speed bilateral filter

4.local laplacian filter implement use pure c++ to enhance local constrast and dynamic range, only remapping in residual layer.

主要包括双边滤波、快速双边滤波（bilateral grid）、以及导线滤波（guided filter） 的图像增强技术。 guided filter 的图像保边效果更好，不会有局部梯度反向问题。