1. A method for correlating a position of a droplet in a first image with a position of the droplet in a second image, comprising: capturing, using an optical detector, a first and a second image of one or more droplets; capturing, using a video detector, a plurality of video frames of the one or more droplets; identifying, using a processor, a first image position of a droplet in the first image of the one or more droplets; transforming the identified first image position of the droplet in the first image from a position in an image coordinate system to a position in a video frame coordinate system to identify a first video frame position of the plurality of video frames; identifying a droplet with a position in the identified first video frame that is closest to the first video frame position; tracking the movement of the droplet from the first video frame to a second video frame to locate a second video frame position of the droplet in the second video frame; and inverse transforming the second video frame position in the video frame coordinate system to a position in the image coordinate system to identify a second image position of the droplet in the second image.