I am a more-than-beginner to imageJ. I am using Fiji. I am trying to analyse (many) pictures of a square on the ground taken from above but not horizontally, resulting in distortion. I want to analyse the proportion of the image covered with vegetation, I thus need to straighten the image to have an accurate measurement. As the particle measurements will count pixels, the pixels of the final image should not be distorted.
I already had a look at TransformJ (http://www.imagescience.org/meijering/software/transformj/) but the plugins ask for entering rotation angles, which I don’t know precisely and which vary from one image to another. The ideal way would be to indicate the four corners of the square and to turn it into an actual square, but I could not find how to do it.
I would appreciate any help, and I beg your pardon for noob questions !