An image processing device for reducing a fixed pattern resulting from repeating cycles in basic array patterns, comprising: image acquisition means configured to acquire an image taken by imaging means including an image sensor having pixel configuration with repeating cycles of M × N pixels, M, N: integers of 2 or more; and filtering means having filters with a K × L filter size, K, L: integers with M < K and N < L, the filtering means configured to calculate a pixel value of the target pixel by setting a target pixel (x, y) inside the acquired image, extracting K × L pixels from the acquired image based on the target pixel, and applying product sum operation to the extracted K × L pixels and filter coefficients of the filtering means of the K × L filter size while using pixels of the same color and the filter coefficients corresponding to the pixels of the same color, wherein the filtering means has the filter having the filter coefficients that are weighted to be larger in a vicinity of a center of the filters, and the filter coefficients are calculated so that where rows of the filters are defined as i m, i (m-1),..., i 1, i 0, i -1,..., i -(m-1), i -m, with i 0 defining one or more rows which are positioned in the central section of the filter and which are identical in arrangement of filter coefficients, while columns of the filters are defined as j n, j (n-1),..., j 1, j 0, j -1,..., j -(n-1), j -n, with j 0 defining one or more columns which are positioned in the central section of the filter and which are identical in arrangement of filter coefficients, when the filter coefficients of the columns which are in a specified positional relationship across the one or more central columns j 0 are added to obtain added filter coefficients as seen in columns (j n +j -1), (j (n-1) +j -2),..., (j 1 +j -n), and then from the added filter coefficients as seen in columns (j n + j -1), (J (n-1) + j -2),..., (j 1 + j -n), the added filter coefficients of the rows which are in specified positional relationship across the one or more central rows i 0 are then added to obtain double added filter coefficients as seen in rows (i m +i -1), (i( m-1)+i -2),..., (i 1 +i -m) as addition values, the obtained (m+(a number of i 0 rows)) × (n+(a number of j 0 columns)) addition values are all equal to each other. image acquisition means configured to acquire an image taken by imaging means including an image sensor having pixel configuration with repeating cycles of M × N pixels, M, N: integers of 2 or more; and filtering means having filters with a K × L filter size, K, L: integers with M < K and N < L, the filtering means configured to calculate a pixel value of the target pixel by setting a target pixel (x, y) inside the acquired image, extracting K × L pixels from the acquired image based on the target pixel, and applying product sum operation to the extracted K × L pixels and filter coefficients of the filtering means of the K × L filter size while using pixels of the same color and the filter coefficients corresponding to the pixels of the same color, wherein the filtering means has the filter having the filter coefficients that are weighted to be larger in a vicinity of a center of the filters, and the filter coefficients are calculated so that where rows of the filters are defined as i m, i (m-1),..., i 1, i 0, i -1,..., i -(m-1), i -m, with i 0 defining one or more rows which are positioned in the central section of the filter and which are identical in arrangement of filter coefficients, while columns of the filters are defined as j n, j (n-1),..., j 1, j 0, j -1,..., j -(n-1), j -n, with j 0 defining one or more columns which are positioned in the central section of the filter and which are identical in arrangement of filter coefficients, when the filter coefficients of the columns which are in a specified positional relationship across the one or more central columns j 0 are added to obtain added filter coefficients as seen in columns (j n +j -1), (j (n-1) +j -2),..., (j 1 +j -n), and then from the added filter coefficients as seen in columns (j n + j -1), (J (n-1) + j -2),..., (j 1 + j -n), the added filter coefficients of the rows which are in specified positional relationship across the one or more central rows i 0 are then added to obtain double added filter coefficients as seen in rows (i m +i -1), (i( m-1)+i -2),..., (i 1 +i -m) as addition values, the obtained (m+(a number of i 0 rows)) × (n+(a number of j 0 columns)) addition values are all equal to each other.