I can't find COCO_val2014.png

[Aitchson-Hwang]

i tried your evaluate.sh. and downloaded your datasets, 10kgray, 10kmid
input "bash examples/evaluate.sh"
but got "FileNotFoundError: [Errno 2] No such file or directory: '/home/dell/watermark/10kgray/masks/natural/COCO_val2014.png'
What's "COCO_val2014.png"?