Flame images are collected and Proper Orthogonal Decomposition (POD) coupled with interpolation is applied to reconstruct information in between consecutive measurements. The POD basis is determined from samples (“snapshots”) taken during experiments conducted on an optically accessible Spark Ignition Engine. Reconstructed luminosity fields are then compared with the available (but not used in the computations) experimental data. In a second application, dynamic in-cylinder pressure data collected together with images are compared to those of a “base” cycle and the differences are used to weight the “snapshots” collected over different cycles. By this means, pseudo-cycle-resolved image sequences can be obtained.