Correcting this problem at the camera will always yield better results than post-capture processing. If your camera will not accept a threaded filter and there is not an adaptor to rig a filter to the camera (ask a good retailer like B&H or Adorama); then you can always simply buy a filter, say 52mm, and manually hold it against your existing lens. Please note that this will ONLY work well if the outer lens element is recessed. In other words, the glass of the filter should not touch the lens glass. It can be awkward to shoot like this, but with a little practice it is very manageable. A UV haze filter will help with your issues, but what you really want is a polarizing filter. To use a polarizing filter you have to rotate it, so that will add another layer of complexity; but since you are taking landscapes there is usually plenty of time to fiddle with gear and still collect the image you want. You will also lose about half a stop with a polarizing filter. Good luck!