;This study investigates the spectral response characteristics and incident-angle sensitivity of CIE tristimulus filters commonly used in imaging-based luminance and chromaticity measurement systems, and evaluates their impact on the accuracy of luminance, chromaticity coordinates, and correlated color temperature (CCT) estimation. First, simulated and experimental analyses were conducted to compare the spectral consistency of the filters with the CIE 1931 standard color matching functions under normal incidence. The spectral variations at different incident angles were then measured to establish an angle–spectrum correction model. Under a coaxial configuration, luminance estimation was performed using the Y filter response, while tristimulus values obtained from the X, Y, and Z filters were paired with luminance meter readings to construct a transformation matrix between grayscale values and tristimulus values via the least squares method. This matrix was subsequently used to derive luminance and chromaticity coordinates. Experimental results indicate that the transformation matrix can accurately convert grayscale values into luminance and chromaticity coordinates under fixed light source and system parameters, with minimal error compared to direct measurements, thus validating its feasibility. The proposed approach reduces reliance on costly commercial luminance meters and offers high spatial resolution, non-contact, and multi-point real-time measurement capabilities. It has potential applications in display calibration, AR optical module testing, smart lighting monitoring, and light-field reconstruction. Furthermore, integrating off-axis response compensation and multi-view measurement is expected to enhance the system’s adaptability and precision.
