Pixel interpolation circuit, pixel interpolation method and image reader

A pixel interpolation circuit for generating interpolation pixel data which interpolates an input image based on pixel data composing the input image, the pixel interpolation circuit comprising:

• a plurality of interpolation circuits each calculating interpolation candidate data of a interpolation pixel and test interpolation data of a plurality of pixels neighboring the interpolation pixel, using different interpolation methods;
• a determining circuit for selecting one of the interpolation circuits based on a difference between the test interpolation data and actual pixel data;
• and
• an output circuit for outputting the interpolation candidate data calculated by the selected interpolation circuit as the interpolation pixel data.