But if the plates are larger than your scanner, you can backlight the glass plate negative and take a picture of it. Then using a program like Photoshop you can invert the image to get a positive.
Either way once you have a positive image then it’s just a matter of digitally patching the area where it’s broken. Unlike the other glass plate example, in this image the break went right through the middle of the image and lots of detail had to be reconstructed.
Using a combination of Photoshop’s clone tool, along with the patch tool and some brushwork, the crack was made to disappear.
We also cleaned up the left and right borders as well as some of the area in the sky.