简单好用的matlab实现批量计算彩色RGB图像的PSNR和SSIM，设置了3种转换方法，（1）matlab自带转换YUV格式，（2）自己编写YUV转换公式（3）matlab自带转换灰度格式(Simple and useful matlab batch computing color RGB image PSNR and SSIM, set up three kinds of transformation methods, (1) with matlab transform YUV format

rgb32或rgb24图像向yuv图像转换方法，查表法，亲测有效(Rgb32 or RGB24 image to YUV image conversion method, look-up table method, pro test effectiveness)