Projector radiometric compensation using a 2D spectroradiometer

Yoshiaki Maeda and Daisuke Iwai

Graduate School of Engineering Science, The University of Osaka

Optics Express, Vol. 34, No. 9, p. 15979 (April 2026)

Abstract

Projection mapping (PM) optically overlays computer-generated imagery onto real-world objects, enabling users to experience augmented reality without wearing any display devices. However, surface textures often cause color distortion, leading the displayed colors to deviate from the desired colors. To address this issue, we propose a projector radiometric compensation method that minimizes the color difference between a target image and the projected result using a 2D spectroradiometer (2DSR). In the proposed method, we model the color transformation between the projector and the 2DSR in a differentiable manner. Based on this formulation, we propose two optimization strategies for projector radiometric compensation: (i) minimizing the spectral error between the target appearance and the projected result, and (ii) minimizing the color difference measured in a differentiable color space designed to reflect human visual perception. Experiments with a physical prototype demonstrate that our method achieves more accurate projector radiometric compensation and better alignment with human color perception than conventional methods using an RGB camera.

**Fig. 2.** Comparison of projection results across objective functions. (a) Visualization images obtained by capturing the proposed-method projections with the 2DSR and converting them to the sRGB color space, along with heatmaps of ΔE₇₆ between the target spectral image and the projection result and the spectral MAE. The corresponding error heatmaps for each column are shown in the second and third rows. To effectively visualize error changes due to different objective functions, the heatmap ranges are clipped at the 98th percentile of the error values. (b) Comparison of mean spectra within the solid rectangular region indicated in the visualization images.

**Fig. 3.** Convergence behavior of the proposed iterative optimization. The evaluation metrics are plotted as a function of the iteration number.

**Fig. 4.** Comparison of projection results across methods. (a) Visualization images obtained by capturing the proposed-method projections with the 2DSR and converting them to the sRGB color space, along with heatmaps of ΔE₇₆ between the target spectral image and the projection result and the spectral MAE. (b) Comparison of mean spectra within the solid rectangular region indicated in the visualization images.

Citation

Yoshiaki Maeda and Daisuke Iwai, "Projector radiometric compensation using a 2D spectroradiometer," Opt. Express 34, 15979–15993 (2026)

@article{maeda2026projectorRadiometricCompensation,
  title   = {Projector radiometric compensation using a 2D spectroradiometer},
  author  = {Maeda, Yoshiaki and Iwai, Daisuke},
  journal = {Optics Express},
  volume  = {34},
  number  = {9},
  pages   = {15979--15993},
  year    = {2026},
  month   = {Apr},
  doi     = {10.1364/OE.596052}
}

Figures 1–4 reproduced from (Maeda & Iwai, 2026), published under the Optica Open Access Publishing Agreement.

Abstract

Citation

References

2026