Cropping 1000 Images - Remove Surrounding Whitespace

We have an E-commerce website with thousands of product. Some of them have alot of whitespace around the product images. We need someone to go through these images and remove the whitespace and upload them back to a FTP server in a specific folder format. We would provide an excel spreadsheet with about 2000 images with links to the images and the person needs to check whether each image needs cropping. Please note, not all the images will require cropping. However, as we don't know the number of images that do need cropping we've put down the task to be for 1000 images. Any questions on the work please ask. We started doing this inhouse and it doesn't take more than 50 seconds per image to crop and save. So please bid accordingly! thanks