An image processing apparatus comprising: a first pixel value generating unit (31, 61) configured to generate a pixel value of a pixel using a first interpolation method being a pattern matching method using a template; a second pixel value generating unit (32, 62) configured to generate a pixel value of a pixel using a second interpolation method different from the first interpolation method; a control unit (33, 63, 73, 83, 93); and a pixel value inserting unit (34, 64) configured to insert, to a target pixel, the pixel value generated by one of the first (31, 61) and second (32, 62) pixel value generating units determined by the control unit (33, 63, 73, 83, 93); characterized by a periodicity determining unit (30, 60) configured to determine whether an image region including the target pixel whose pixel value is to be interpolated is a periodic region in which pixel values vary periodically; and the control unit (33, 63, 73, 83, 93) being configured to determine, based on the determination result obtained by the periodicity determining unit (30, 60), which one of the first (31, 61) and second (32, 62) pixel value generating units is to be used for generating the pixel value of the target pixel, wherein the first pixel value generating unit (31, 61) is used if the image region is a periodic region and the second pixel value generating unit (32, 62) is used otherwise; wherein the periodicity determining unit (30, 60) includes at least one of: a cycle estimating unit configured to estimate, using pixel values of respective pixels within the image region including the target pixel, a variation cycle of the pixel values, the variation cycle representing a number of pixels; and a partial region periodicity determining unit configured to determine whether each of regions positioned at left and right sides of the target pixel is a periodic region, and wherein the first pixel value generating unit (31, 61) generates the pixel value of the target pixel using at least one of the variation cycle of the pixel values estimated by the cycle estimating unit and the determination result determined by the partial region periodicity determining unit, wherein using the variation cycle involves determining the size of the template used in the pattern matching based on the variation cycle and using the determination result determined by the partial region periodicity determining unit involves determining an image region to be searched in order to retrieve a pattern similar to the template used in the pattern matching, based on the determination result determined by the partial region periodicity determining unit. a first pixel value generating unit (31, 61) configured to generate a pixel value of a pixel using a first interpolation method being a pattern matching method using a template; a second pixel value generating unit (32, 62) configured to generate a pixel value of a pixel using a second interpolation method different from the first interpolation method; a control unit (33, 63, 73, 83, 93); and a pixel value inserting unit (34, 64) configured to insert, to a target pixel, the pixel value generated by one of the first (31, 61) and second (32, 62) pixel value generating units determined by the control unit (33, 63, 73, 83, 93); characterized by a periodicity determining unit (30, 60) configured to determine whether an image region including the target pixel whose pixel value is to be interpolated is a periodic region in which pixel values vary periodically; and the control unit (33, 63, 73, 83, 93) being configured to determine, based on the determination result obtained by the periodicity determining unit (30, 60), which one of the first (31, 61) and second (32, 62) pixel value generating units is to be used for generating the pixel value of the target pixel, wherein the first pixel value generating unit (31, 61) is used if the image region is a periodic region and the second pixel value generating unit (32, 62) is used otherwise; wherein the periodicity determining unit (30, 60) includes at least one of: a cycle estimating unit configured to estimate, using pixel values of respective pixels within the image region including the target pixel, a variation cycle of the pixel values, the variation cycle representing a number of pixels; and a partial region periodicity determining unit configured to determine whether each of regions positioned at left and right sides of the target pixel is a periodic region, and a cycle estimating unit configured to estimate, using pixel values of respective pixels within the image region including the target pixel, a variation cycle of the pixel values, the variation cycle representing a number of pixels; and a partial region periodicity determining unit configured to determine whether each of regions positioned at left and right sides of the target pixel is a periodic region, and wherein the first pixel value generating unit (31, 61) generates the pixel value of the target pixel using at least one of the variation cycle of the pixel values estimated by the cycle estimating unit and the determination result determined by the partial region periodicity determining unit, wherein using the variation cycle involves determining the size of the template used in the pattern matching based on the variation cycle and using the determination result determined by the partial region periodicity determining unit involves determining an image region to be searched in order to retrieve a pattern similar to the template used in the pattern matching, based on the determination result determined by the partial region periodicity determining unit.