To install an image you need to bit for bit copy the image onto the target drive. This can be a little tricky because copy operations are usually designed to work with files not drive images. You will need a host computer to copy the image to the target drive. In some cases the host and target can be the same computer.
For i386 computer we are releasing images using a modified clonezilla. With these images you can boot the target computer from a CD or USB key then install the image. You don't need another computer.
Far ARM images you will need a computer (mac, Windows, or Linux) to install the image on the boot media.