Okay, so I recently took a group photo of my GATE students (I'm a teacher).
When I went to Costco to get these printed out, no matter what size I chose, it would cut off some of the students. Is there anyway I can edit my picture without loss of quality for Costco's printers to print the ENTIRE picture?
Choose what size you want to print at Coscto (eg 8"x10"), you have a setting for Costco' printer to crop the photo from top/bottom (left/right), or to leave white bands from left/right (top bottom).
If you don't want the photo to be cropped, or having white bands - re-crop it to have same ratio as the target print (eg, if target print will be 8x10, crop your photo to eg 2400x3000 pixels). Get the current size of your photo, and give them to your math teacher for help.