Function to import image from file

[rpodcast]

I realize this may be out of your original scope, but I think it would be convenient to have a (wrapper) function to import an image from file. For the app I allowed for JPEG or PNG files to be imported. In the case of PNG files, I used the magick to convert the image to JPEG and then simply used jpeg::readJPEG() like your earlier prototypes. You can see how I used this in my import module here. Happy to turn this in to a function for the package if you are on board with this idea.