1. An image processing apparatus having an image readout sensor that is provided with a plurality of pixels that optically reads out an image, and a driving unit that moves the image readout sensor, the image processing apparatus comprising: a control unit which controls the driving unit and the image readout sensor by causing the driving unit to move the image readout sensor so that each of the plurality of pixels reads out a chart that has a predetermined pattern; a calculation unit which calculates a feature amount of the plurality of pixels from image data of each pixel that has been read out through the control performed by the control unit; an analysis unit which analyses MTF characteristics of the plurality of pixels based on the feature amount calculated by the calculation unit; and a correction unit which corrects nonuniformity of the MTF characteristics of the plurality of pixels based on the result of the analysis performed by the analysis unit.