An image processing apparatus includes a high-resolution converting unit configured to use image data of a plurality of frames of images in which positions read by a sensor are shifted by less than one pixel in a main scanning direction and/or a sub-scanning direction to generate image data having resolution higher than resolution of the sensor, an image region information generating unit configured to generate image region information corresponding to the image data read by the sensor, and an image region information high-resolution converting unit configured to convert a format of the image region information generated by the image region information generating unit and to perform a high-resolution conversion on the image region information using the high-resolution converting unit in such a way as to cause the image region information to correspond to the image data having the resolution higher than the resolution of the sensor.