For the purposes of the images.testing vocab, a reference image is an image which has been serialized to disk by the serialize vocab. The file on disk has a .fig extension.

Reference images are used by decode-test to compare the decoder's output against a saved image that is known to be correct.

You can create your own reference image after you verify that the image has been correctly decoded:

save-as-reference-image ( path -- )

save-all-as-reference-images ( dirpath extension -- )

A reference image can be loaded by the path of the original image:

load-reference-image ( path -- image )