This method is the most basic and fastest method. In histogram compare method, "CompareHist ()" function is performed, and color-based comparisons are made. The method gives a very simple feedback. We can use those methods to compare histogram images; "Correlation, Chi-Square, Intersection and Bhattacharyya Distance" .In conclusion, i mentinoed and posted other image comparasion methods. Histograms is the easiest one so it has drawbacks. In the comparation results, errors occurs, because histogram method only compare colors in images. On the other hand it is ideal for simple comparisons. Improvements can be made to the image before using this method.
With this method, image similarity rate and percentage can easily be calculated. But as i mentinoed before, we need to use select an algorithm. The results may vary depending on the algorithm.