Wavefront aberration can well reflect the performances of optical system. The test result of wavefront is usually expressed in a linear combination of Zernike polynomials. The wavefront of the transmission optical system needs to be tested at specific wavelengths. From now on, only a few wavelength wavefronts can be accurately tested because of the limitation of detection instrument. A new idea is put forward in this paper, the wavefront can be tested at any wavelength by analyzing the functional relationship between transmitted wavefront Zernike coefficients and wavelength, which can indirectly reflect the variation of the wavefront with the wavelength. The optical system is modeled by Zemax. The wavefront Zernike coefficients of the optical system at different wavelengths are collected. Then the possible function form of the curve of the Zernike coefficients and the wavelength are fitted by Matlab curve fitting tool. Finally, the Conrady-Zernike formula is determined. The maximum error of the calculated Zernike coefficients is within 1%, which is calculated by the Conrady-Zernike formula in the simulated optical system. The results show that the wavefront Zernike coefficients and the wavelength of transmitted optical system are basically consistent with the Conrady-Zernike formula.

Combined with the visual attention mechanism, the influence of contrast factor on visual comfort of stereo image is studied quantitatively through a large number of subjective experiments. First, a stereo salient degree map is derived from stereo disparity map and planar salient map. It is optimized through fuzzy membership degree and mask, and the salient stereoscopic images can be obtained. An eye tracker is used to verify its rationality. Then, a series of subjective experiments are conducted after contrast conversion of left and right views. Finally, the comfortable contrast matching map and difference map are obtained after data screening. The experimental results show that the contrast difference thresholds of left and right view change with different left view contrasts, and the contrast difference should not be too large. The maximum and minimum difference values are 1.97 and -2.40, respectively. The obtained comfortable contrast ranges reflect the comfort of stereo image better, and the correct rate reaches 95%, which provides more reasonable and feasible quantitative standards for the making of stereo contents.

ing at the problems of noise-sensitive, easy distortion and with high false matching ratio in the disparity discontinuity region and weak texture region of the existing local matching algorithm, a multi-scale stereo matching algorithm for improved Census transform and gradient fusion is proposed. The weighted average gray value of all the pixels in the support window is used as the reference value of the Census transform. The Census cost is weighted combined with the gradient cost normalized by the horizontal and vertical directions, and a stable cost is obtained when the noise margin is set. Therefore, the reliability of the single pixel matching cost is obtained. Under the multi-scale, the improved guided filtering algorithm is used to complete the aggregation of the matching cost. The disparity map is obtained by parallax extraction. The experimental results demonstrate that the average false matching ratio of standard stereo image pairs obtained by the proposed algorithm is 4.74% on the Middlebury testing benchmark, and the average false matching ratio of the 27 extended stereo image pairs is 8.67%. In the parallax discontinuity region and the weak texture region, the false matching ratio is further reduced by the proposed algorithm, and it shows better robustness for noise and light.