1. An image processing apparatus capable of controlling an amount of a recording material corresponding to image data, the image processing apparatus comprising: a storage unit configured to store a gradation correction table calculated based on data acquired by reading a patch pattern formed by an image forming unit; a calculation unit configured to calculate a maximum density value of an image formed by the image forming unit using an output signal value corresponding to a maximum value of an input signal in the gradation correction table and a maximum density value to be targeted by the image processing apparatus; an acquisition unit configured to acquire an amount of toner required at the time of outputting the maximum density value of the image formed by the image forming unit, using the maximum density value of the image formed by the image forming unit and the maximum density value to be targeted by the image processing apparatus; a determination unit configured to calculate an exceeding amount of toner that exceeds an estimated limit value, from the amount of toner acquired by the acquisition unit, and determine a value remaining by subtracting the exceeding amount of toner from the estimated limit value, as a limit value of a total amount of a plurality of recording materials; and a control unit configured to control the total amount of the plurality of recording materials corresponding to the image data to be equal to or less than the limit value determined by the determination unit, wherein the limit value of the total amount of the plurality of recording materials determined by the determination unit varies according to a difference between the maximum density value of the image formed by the image forming unit and the maximum density value to be targeted by the image processing apparatus, wherein as the maximum density value of the image formed by the image forming unit becomes larger than the maximum density value to be targeted by the image processing apparatus, and the exceeding amount of toner increases in conjunction with increase of the maximum density value of the image formed by the image forming unit, the limit value of a total amount of a plurality of recording materials becomes smaller, and wherein as the maximum density value of the image formed by the image forming unit becomes larger than the maximum density value to be targeted by the image processing apparatus, and the exceeding amount of toner increases in conjunction with increase of the maximum density value of the image formed by the image forming unit, the total amount of the plurality of recording materials corresponding to the image data that the control unit controls becomes smaller.