So ridiculously big... someone has actually made an image compression format specifically for visual novel CG since they duplicate so much content across multiple images, but it's too obscure for it to be of any use. http://spillerrec.dk/2014/02/compressing-vn-cgs/
I'm tempted to make a torrent but I'm not sure anyone would want to download 4.8GB, lol.
@namaemoi 7z can't compress the .png at all, but it can do a pretty good job on the uncompressed .bmp The link I posted shows a comparison, and proposes a new format that is even better. But there is no easy way to use that format right now. I'm trying to ask the developer to make it simpler.
Actually, I'll grab this and turn it into bmp's and 7z it and put up a torrent if it works out. Thanks for the tip. The problem is that you need a image gallery viewer that can directly view the .7z file, or else extracting uncompressed BMP to view them will be really big.
edit2: Oh and the biggest issue with BMP is that it doesn't support transparency, unfortunately.
you know the 7z archive can compress this entire gallery into around 300MB or less without degrading the quality 7z torrent is denied in E-H system?
edit: @awvnx i appreciate it sorry i can't say much well
edit2: BMP DOES support transparency. The BMP 32-bit per pixel format contains alpha channel data (24-bit format is not), but most of image viewers ignore it and show only RGB. If you use right software, there is no problem that transparency PNG convert to BMP, and vice versa. I don't really want you upload torrent, though.