I am confused about the format,'.gntx' in [CASIA-AHCDB](http://www.nlpr.ia.ac.cn/pal/CASIA-AHCDB.html). How to convert it to a png file, is it similar with 'gnt' format?
I am confused about the format,'.gntx' in CASIA-AHCDB. How to convert it to a png file, is it similar with 'gnt' format?