I come from a background in photojournalism where a photograph submitted for publishing is compared to the original source to see if the photograph has been manipulated into a photo-illustration. What is the definition of a photograph for the contest? Straight out of the camera, minor editing or anything goes? Just curious.
As long as the submission stays true to its source there should be no problem. What is meant by this I will try to explain below.
Cropping is fine and expected.
Color manipulation is accepted
Panoramic stitching is accepted. However, merging two or more images is not. You can't take a picture of dining table, then cut the turkey from a different photo to paste into the dining table picture.
Hope this helps.