The present method utilized the hue-angle method to process the color images captured from the liquid crystal color play. Instantaneous temperature readings from embedded thermocouples were utilized for in situ calibration of hue angle for each data set. The convective heat transfer coefficient results were obtained by performing a 3-D inverse transient conduction calculation over the entire jet impingement target surface and the substrate. The results of average heat transfer coefficients agreed well with previous experimental results of point measurements by thermocouples. Comparison between 1-D and 3-D results indicates that 1-D results are higher than the 3-D results with the local maximum and minimum heat transfer values being overvalued by about 15–20% and the overall heat transfer by approximately 12%. This is due to the fact that 1-D method does not include the lateral heat flows induced by local temperature gradients.