the idx should contain offsets into the bin file, iirc
I can't get fiitting offsets from the bin/idx pair you provided.
But there's much uncompressed data in the bin - search for 'skeleton' to see what I mean.
Got some skeleton at 0x3d50, FVFsize=64:
PSP00_chouun_M3.Skeleton_0.jpg
You do not have the required permissions to view the files attached to this post.