Probably not a faster way than doing it by hand unfortunately.
You may be able to make a tool to help with the process a bit, but it will still involve having to make a selection around each sprite, and then align it to another frame so everything matches up. Even if you match up the pixels perfectly, you will find frames that have been designed so that the foot moves a pixel or 2. and you will only see this when scrubbing through the frames to see the motion.
It's definately a bit of a task,... you may be better off trying to find a different spritesheet that is not all cut up.
You may be able to make a tool to help with the process a bit, but it will still involve having to make a selection around each sprite, and then align it to another frame so everything matches up. Even if you match up the pixels perfectly, you will find frames that have been designed so that the foot moves a pixel or 2. and you will only see this when scrubbing through the frames to see the motion.
It's definately a bit of a task,... you may be better off trying to find a different spritesheet that is not all cut up.