Active stereo vision is a 3D measurement method which uses a projector-camera system. These almost methods require linearity between a projector intensity value and camera intensity value. However, the relationship of the intensities is not linear in practice because of projector gamma and saturation on the camera pixel. Therefore, we have to calibrate it to be linear before 3D measurements. We developed a program which calibrates the relationship on a projector-camera system. In this paper, we examined our proposed method by applying to two 3D measurement methods: Phase Shift and LT Matrix Estimation. Both of them requires linearity between a projector intensity value and camera intensity value, and they perform better with proposed method than without optical calibration.