I am an extreme beginner with any software of this type. I have an image I took from an iPhone 6 video, and I am trying to make it less grainy. The video was rather dark to begin with, so when I brighten the picture it becomes very noisy.I tried using all of the denoise filters I could find, including Live Filter Layers and just using Filters, including Denoise and Deinterlace, since the picture was taken from a video. None of the filters seem to do anything at all, as far as noise or graininess goes. I have a new iMac with 24 gb of memory. I looked through most of the tutorials that had anything to do with either noise or graininess but I can't seem to apply those methods to the picture. What am I doing wrong?