The present technology is directed to determining an accuracy of an infrared (IR) camera, and more particularly, validating a distortion accuracy of an IR camera. The present technology can receive one or more images of a calibration harp captured by the IR camera, wherein the one or more images include a plurality of lines corresponding to a plurality of strings of the calibration harp. The present technology can further determine a degree of distortion of the plurality of lines based on a distortion error coefficient, wherein the distortion error coefficient is computed based on edge points of the plurality of lines on the one or more images.