Moire compensation in 2D colorimeter using adaptive spatial-frequency filter

•We propose a compensation method of moiré in imaging 2D colorimeters without Optical Low Pass Filter (OLPF).•A moiré model based on system theory is introduced, and regarding this model novel moiré compensation filters in spatial and frequency domain are performed for preserving of display features.•Experimental results have shown that the proposed method has sufficient performance to be used in high-precision imaging colorimeters. The paper describes effective compensation of moire in a two-dimensional (2D) colorimeter using CMOS sensor without an Optical Low Pass Filter (OLPF) for display measurements. First, frequency characteristics of moire were modeled using a conventional system theory, and based on this moire model, a measured moire was characterized experimentally using the discrete Fourier transform (DFT). A detected moire in the frequency domain will be then compensated using spatial and frequency filters with minimizing loss of image details of displays, such as pixel-, line-defects and local variations in tristimulus values. Result images of the proposed method were compared with moire-free reference images. Experimental results have shown that the proposed method has sufficient performance to be used in high-precision imaging colorimeters.