Increase image generation speed for camera-simulator

[VigneshVSV]

The computations to generate the images, which uses hermite-gaussian modes & overlaps them, are good to see as an image, but they reach only 4-5 even on 4GHz CPU.

The following need to be done

• allow beam size modification based on random increase and decrease
• increase speed of generation by using better computational methods
• incorporate FPS property so that the image events are seen with that FPS (30FPS is already good, higher is better)