Accurately measuring translations between images is essential in many fields,
including biology, medicine, geography, and physics. Existing methods,
including the popular FFT-based cross-correlation, are not suitable for
real-time analysis, which is especially vital in feedback control systems. To
fill this gap, we introduce a new algorithm which approaches shot-noise limited
displacement detection and a GPU-based implementation for real-time image
analysis.Comment: 4 pages, 3 figures, submitted to Optics Letter