Image upload script edit php mysql site

We have an existing php mysql website with an image upload page. We are looking at adding more functionality so that when an image is uploaded, a crop window will display on the uploaded image. The crop window will be square and of the same dimensions of the smallest dimension of the image being uploaded. For instance if the image is 300 x 200 - the crop window will be 200x200. If the image is 100 x 500, the crop window will be 100x100. The user will then be able to drag the crop window over the image to select the part of the image to be uploaded. After the crop window is in place - the user can then click on upload to crop the image and save the file to disk. The current tool already does the image upload and saving to disk (as well as a reduction in size prior to saving to disk). The upload caters for 3 images already - so the crop must work on all 3 images. Payment for this project will be available after 3 days of testing in production - so please do not expect payment without the 3 days of testing in production. This will give you piece of mind that your code is working as designed and you achieved what you set out to do. Ive uploaded an image showing the current image upload in place.