Fig. 1. Color filter array based on Bayer rule

Fig. 2. Simulation images. (a) Original image; (b) degraded image; (c) image after adding noise

Fig. 3. Filtering results. (a) Gaussian filtering with a variance of 2; (b) adaptive filtering

Fig. 4. Edge detection results. (a) Detection result of original Canny operator; (b) detection result of improved Canny operator

Fig. 5. Principle of ESF curves obtained by projection method

Fig. 6. Simulation results of MTF. (a) Simulation results of ISO 12233 method; (b) simulation results after processing with cubic spline interpolation algorithm; (c) simulation results of improved algorithm based on NUFFT

Fig. 7. MTF relative error of different algorithms

Fig. 8. Result comparison of three methods at different SNRs

Fig. 9. RGB three primary color QE curves

Fig. 10. Light source spectral radiation test site

Fig. 11. Spectral radiation energy distribution curve of light source

Fig. 12. Color space camera MTF test equipment

Fig. 13. Images of knife-edge target. (a) Knife-edge target; (b) color image; (c) original Mono image

Fig. 14. MTF test results of color image after interpolation

Fig. 15. MTF test results obtained by Mono image weighting calculation

Fig. 16. MTF calculation results of different algorithms. (a) MTF calculation results of ISO 12233 method; (b) MTF measurement results of improved edge detection algorithm and cubic spline interpolation method; (c) MTF measurement results of the improved knife-edge algorithm