by analyzing an image signal of the preview image based on a frequency domain for instance the frequency analyzing unit 110 can obtain an image frequency of the preview image in a spectrum form by performing a fast fourier transform on the image signal obtained by the image sensor 104 the frequency comparing unit 120 compares the image frequency of the preview image obtained by the frequency analyzing unit 110 and a spatial frequency of the image sensor 104 the spatial frequency of the image sensor 104 which is a unique property of the image sensor 104 can be obtained by taking the inverse of a distance between unit image pick up devices which comprise the image sensor 104 furthermore the frequency comparing unit 120 compares the image frequency of the preview image and the spatial frequency of the image sensor 104 in order to determine whether the image frequency of the preview image is present in a particular region around the spatial frequency of the image sensor 104 the particular region may range between about u00b1 25 percent of the spatial frequency of the image sensor 104 if the image frequency of the preview image is present in the particular region around the spatial frequency of the image sensor 104 there is a high possibility of the occurrence of a moire pattern due to frequency interference between the image and the sensor therefore it can be determined that the moire pattern is created when the image frequency is present in the particular region around the spatial frequency of.