1. A method of processing image signals, comprising: generating an n×n kernel by selecting input pixel data that includes current pixel data and a plurality of neighbor pixel data, n being an odd integer greater than two; storing coordinates for each bad pixel in a non-volatile memory device if at least one additional bad pixel is located in an area of n×n pixels centered around each bad pixel; determining whether each unit of the input pixel data is bad pixel data based upon the coordinates for each bad pixel; and generating image data by estimating the current pixel data based on the determining of whether each unit of the input pixel data is bad pixel data, wherein, based on the coordinates for each bad pixel, and upon determining that at least one of the plurality of neighbor pixel data is bad pixel data, and upon further determining that the current pixel data is normal pixel data, the estimating of the current pixel data comprises outputting the current pixel data, else upon determining that the current data is bad pixel data based upon the coordinates for each bad pixel, the estimating of the current pixel data comprises performing an interpolation using only the normal pixel data, else upon determining that the current pixel data and all of the plurality of neighbor pixel data are normal pixel data based upon the coordinates for each bad pixel, the estimating of the current pixel data comprises; using only the plurality of neighbor pixel data if an average of differences between a value of the current pixel data and a value of each of the plurality of neighbor pixel data is greater than or equal to a predetermined value, else outputting the current pixel data if the average of the differences between the value of the current pixel data and the value of each of the plurality of neighbor pixel data is less than the predetermined value.