Moire reduction using inflection point in frequency domain

Digital still cameras generally use an optical low-pass filter(OLPF) to enhance the image quality by removing high spatial frequencies causing aliasing. While eliminating the OLPF can save manufacturing costs, images captured without using an OLPF include moire in the high spatial frequency region of the image. Therefore, to reduce the presence of moire in a captured image, this paper presents a moire reduction method without the use of an OLPF. First, the spatial frequency response(SFR) of the camera is analyzed and moire regions detected using patterns related to the SFR of the camera. Using these detected regions, the moire components represented by the inflection point between the high frequency and DC components in the frequency domain are selected and then removed. Experimental results confirm that the proposed method can achieve moire reduction while preserving detail information.