opening a local image file, using pixpipe.FileImageReader
converting it into a pixpipe.Image2D object
croping it to keep only the center with pixpipe.Image2D
display the crop in a canvas using pixpipe.CropImageFilter
The first image displayed is the original. The second is the cropped.
The cropped image discards the top/bottom/left/right quarters from the input, leaving only the middle half.