1. An image processing apparatus that accepts an instruction for processing with respect to target image data, and transmits image data together with instruction information including an instruction for processing to an image processing apparatus in the next stage, the image processing apparatus comprising: a determination unit, configured to evaluate a difference between first image data obtained by performing instructed geometric transformation processing on the target image data and performing instructed correction processing on the geometrically converted image data and second image data obtained by performing the instructed correction processing on the target image data, and determine whether the difference exceeds a predetermined value; a re-setting unit, configured to set again, if the determination unit determines that the difference exceeds the predetermined value, a parameter of the geometric transformation processing such that the difference between the first image data and the second image data is equal to or less than the predetermined value; and a transmission unit, configured to perform the geometric transformation processing on the target image data using the parameter set by the re-setting unit, and transmit, to the image processing apparatus in the next stage, image data resulting from the processing together with instruction information indicating the instructed correction processing and instruction information indicating the instructed geometric transformation processing.