Before revision:  The metrics of root mean square error (RMSE or accuracy) , precision, recall, and Jaccard index (JAC) are currently used in the literature but in certain conditions fail in distinguishing qualities of different nanoscopy images .
After revision:  The metrics of root mean square error (RMSE or accuracy) , precision, recall, and Jaccard index (JAC) are currently used in the literature , are analyzed. A numerical example demonstrates the advantages of RMSMD over the four existing metrics that fail to distinguish qualities of different nanoscopy images .