I'm not sure what you are trying to do or what you are trying to use as a wallpaper, but I just set wallpapers from the "Personalize" button next to Phone on the main screen. Hit Personalize, then go to the middle "Display" pick "Wallpaper" and then "Gallery" (I have most of the pics I would use available from the Gallery) and chosse Gallery again. If the file you want to use isn't in your Gallery and you have Astro or some other file explorer program installed, that will be an option and you can search for your file that way.
When you pick a file, it will give you a movable selection square - I know, your wall isn't square. HTC didn't change this from prior versions of Sense where the wallpaper rotates as you flip through the screens. Whatever you fit inside your square, only the center portion will be visable. If your pic is exactly the right size for the Rezound screen, you won't be able to get all of it in. I have added black space to either side of some pics so that the square would be centered on the part you want as wallpaper. On others that aren't exactly the right size, i don't mind if it cuts of a portion of the picture on each side.
Maybe you've already done this and weren't happy with the results - if so disregard this. I've found I can get most pictures to fit one way or another (sometimes it just takes a little tweakin"!)
Good luck.
Facebook
Twitter
Instagram