ImageReflect

ImageReflect[image] reverses image by top-bottom mirror reflection. 

ImageReflect[image,side] reverses image by reflecting it so that the specified side goes to the opposite side.

ImageReflect[image,side1->side2] reflects image so that side1 is interchanged with side2.

ImageReflect[video,…] reflects frames of video.

Please visit the official Wolfram Language Reference for more details and examples on core symbols.