An image processor inputs image data from an image capturing device, and acquires blur-correction coefficients corresponding to the state of an imaging optical system which forms an image represented by light coming from an object on the image capturing device. Then, the image processor generates a target component and non-target components of blur correction from the image data, applies blur correction to the target component based on the blur-correction coefficients, and generates image data by synthesizing the target component after the blur correction and the non-target components.