1. An image correction system for correcting image data from pixels connected to at least two different input paths, the image correction system comprising: a memory for storing instructions; and a processor coupled to the memory, the processor configured to execute the instructions thereby implementing: an input circuit which inputs image data of a correction target; a pixel value relationship extraction circuit which extracts a relationship of pixel values among adjacent pixels from the image data of the correction target; a pixel value relational expression estimation circuit which estimates a relational expression representing a characteristic difference at each pixel from the relationship of the pixel values among the adjacent pixels; a pixel value correction circuit which generates a correction image by correcting pixel values of the image data of the correction target using the relational expression; and an output circuit which outputs the correction image.