Automation In Cropping

If all your image are product images and good white backgrounds like you example.  The process can most likely be automated via an action or script.  You would trim the white background to the product.  You would then fit the product image to some image Pixels size like X pixels wide by Y pixels.  Then you would add White canvas so the image would be the size you want  X Pixels + X boarder Pixels by Y Pixels + Y Boarder Pixels.  Any pixels that were not fill in by Fit Image will be filled with white during the final Canvas size. The extra white borders could be as small a 1 Pixel or as large as yout blue arrows are long.  A very easy action to record. Three simple steps Trim, Fit Image, Canvas Size.

It is almost the exactly the same question as here, with the same/similar solutions:

How to automate the cropping procces of this type of images with script

Do you want t extend canvas size? It can be done using Canvas Size dialog. Te only problem you may have is that recorded step will be executed with every image in the batch. There are some conditional steps which can be used but do not count too much on that option.

You could create an action that Trims the image, and then adds the required canvas, and run the action in the Image Processor. Obviously  Trim would only  crop as far as the faintest of shadows, but in your example, the shadows barely extend outside the shoe.

Note, if you have different image sizes, then you might find that setting the Rulers to Percentage when making your action gives you a more consistent result.