Themify my pictures

I would love a built in way to themify my personal pictures. The new themes are great and the artist work is stunning. And sometimes I want a picture of my kids that fits under the clock widget and to the right of the dots. Or has the main focus of the picture at the very top and the clock and apps underneath that. If y'all had a way to “themify" a picture that automatically cropped and added a dark color from the image to a new image so that it worked with the Niagara layout, that would be awesome.