1. An image interpolation apparatus formed by connecting contact image sensors to interpolate a missing pixel, each of the contact image sensors being formed by arranging scan elements in a line, the missing pixel existing between the contact image sensors, comprising: an extracting unit for extracting pixels around the missing pixels in order to form a basic frame and comparative frames, the basic frame being formed by at least three pixels including the missing pixel, the missing pixel being located at a head or tail of the pixels in the basic frame, each of the comparative frames including the same number of the pixels as the basic frame, wherein at least one pixel of the pixels in one comparative frame does not overlap the pixels in the other comparative frames; temporal interpolation calculators, each temporal interpolation calculator corresponding to each of the comparative frames, and calculating a temporal interpolated pixel for each of the comparative frames based on signal levels and a variation of the signal levels in terms of a first pixel group and a second pixel group, the first pixel group including adjacent pixels of the missing pixel in the basic frame, the second pixel group including an edge pixel corresponding to the missing pixel and adjacent pixels of the edge pixel in the comparative frame; pattern matching units, each pattern matching unit corresponding to each of the comparative frames, inserting the temporal interpolated pixel of each comparative frame to the missing pixel, calculating difference between each of the pixels in the basic frame and each of the corresponding pixels in the comparative frame, and summing up the differences for all pixels in absolute value to obtain sums for all comparative frames respectively; and an output unit outputting the temporal interpolated pixel having a minimum sum among the sums as a final interpolated pixel.