If you need to mount an image file as a disk partition you can follow the following steps. I have followed these to mount a junos space disk image indeed. Here are the steps:
Then try to mount:
mount: Stale NFS file handle
It fails right? To get where the sector starts on this image
space-11.4R1.5.img: x86 boot sector; partition 1: ID=0×83, active, starthead 1, startsector 62, 3890066 sectors, code offset 0×31
Sector is 62 from which we calculate offset as 62*512=31744 and partition id is 83. It is linux and file system type is ext2, now mount!
#mount -t ext2 -o ro,loop,offset=31744 space-11.4R1.5.img /mnt/space-disk
LiveOS ks.cfg lost+found space-11.4R1.5.iso syslinux
Here is the partition content!