I have a image cameraman.tif ,I have to apply PSO to this image and have to find PSNR,can we apply PSO for Images
You can apply PSO to data matrices such as are created when you imread() an image.
Well, from the description of Particle Swarm Optimization http://en.wikipedia.org/wiki/Particle_swarm_optimization, it appears that you need to have a function that you want to optimize. There's not just one formula that applies to all PSO situations. Have you checked the File Exchange?