A detection device that includes a setting component, a measuring component, an accumulating component, a determining component, and an increasing/decreasing component is provided. The joint quantity measuring component measures joint quantities between the photoelectric conversion elements that are dependent on precision when arraying the plural photoelectric conversion elements. The joint error quantity accumulating component accumulates error quantities of the joints that are obtained from the joint quantities that have been measured and a reference quantity. The determining component determines whether or not the accumulated error quantity has exceeded an allowable range. The interpolation pixel increasing/decreasing component increases/decreases, on the basis of direction of error, interpolation pixels between specific photoelectric conversion elements when it has been determined that the accumulated error quantity has exceeded the allowable range.