GCMM(Gray and Chroma Mapping Method) is the only calibration method dedicated for ultrasound imaging that has been developed by KOSTEC to minimize the display image inconsistency between displays and finally provide consistent and desirable ultrasound images for the clients. Unlike the two-dimensional calibration by white balance technology, GCMM is based on the three-dimensional calibration LUT designed by KOSTEC, which resulted from the sub-divided gray & chroma mapping and calibration of each R,G,B values. Connected with the SBC technology, GCMM is the only way to achieve the consistency of a desirable ultrasound image between displays.