Real-Time Computation of Moment Invariants Combined With Contrast Stretching

There is a large body of evidence that demonstrates the practicable use of moment invariants in real-time computer vision applications. Object detection, recognition and tracking are some of them, to name a few. However, the efficacy of moment invariants is highly susceptible to varying illumination conditions, which is inherent in real-world applications. Contrast stretching alleviates the problem, but performing contrast stretching prior to the calculation of moment invariants is computationally intensive and not suitable for real-time use. The authors' address this problem by proposing an efficient real-time method that integrates the calculation of moment invariants up to the 4th order with a contrast stretching operation (all in one go), by utilizing Summed-Area Tables (SATs).