Did you deleted photos from your computer? Maybe you can restore them in recycle bin, check it firstly.

If you can't  find any file in recycle bin, I think you did a total deletion. However, there still are ways for photo recovery. Deleted won't wiped from hard drive space at once until new data save to the space, so you can use recovery software to recover lost photos from computer.

You can use professional data recovery . know more here: http://www.card-data-recovery.com/usb/kingston-usb-data-recovery.html