as you see, there is very little distortion in this image, which allows to get a corrected perspective just using distortion tool in photoshop. See next image. This image was taken with default jpeg sharpening. Please note the hallos and artifacts around the wires. Please also see how this kind of hallos have disapeared in this photo http://www.pbase.com/lorin/image/120700696 with sharpening set at -2.