An image processing apparatus (900, 940) that processes data made use of for printing an image by relatively moving a printing unit and a printing medium, wherein the printing unit includes a plurality of ink ejection ports arranged in a first direction, and wherein the relative movement is in a second direction that intersects with the first direction, the image processing apparatus comprising: an acquisition unit (900, 901) configured to acquire image data corresponding to an image of one page; a first processing unit configured to process first image data corresponding to a first processing area of the image, for generating first print data that is used for the printing unit, wherein each pixel arranged in the second direction included in the first image data is processed using a first common parameter for correcting; a second processing unit configured to process second image data corresponding to a second processing area of the image, for generating second print data that is used for the printing unit, wherein each pixel arranged in the second direction included in the second image data is processed using a second common parameter for correcting, and wherein a position of the second processing area is different from a position of the first processing area in the first direction within one page, and wherein a printing element to be used for printing the first processing area is different from a printing element to be used for printing the second processing area; and a transmission unit configured to transmit the first image data to the first processing unit and to transmit the second image data to the second processing unit in a unit of band data corresponding to one band area, wherein the first processing area comprises a plurality of band areas, a length of each of the band areas of the first processing area is shorter than a length of the first processing area in the first direction, the second processing area comprises a plurality of band areas, and a length of each of the band areas of the second processing area is shorter than a length of the second processing area in the first direction, wherein the transmission unit transmits a plurality of units of band data to the first processing unit, and wherein during a period extending from a start of the transmission of the plurality of units of band data to the first processing unit to an end of the transmission of the plurality of units of band data to the first processing unit, the transmission unit transmits at least one unit of band data to the second processing unit. an acquisition unit (900, 901) configured to acquire image data corresponding to an image of one page; a first processing unit configured to process first image data corresponding to a first processing area of the image, for generating first print data that is used for the printing unit, wherein each pixel arranged in the second direction included in the first image data is processed using a first common parameter for correcting; a second processing unit configured to process second image data corresponding to a second processing area of the image, for generating second print data that is used for the printing unit, wherein each pixel arranged in the second direction included in the second image data is processed using a second common parameter for correcting, and wherein a position of the second processing area is different from a position of the first processing area in the first direction within one page, and wherein a printing element to be used for printing the first processing area is different from a printing element to be used for printing the second processing area; and a transmission unit configured to transmit the first image data to the first processing unit and to transmit the second image data to the second processing unit in a unit of band data corresponding to one band area, wherein the first processing area comprises a plurality of band areas, a length of each of the band areas of the first processing area is shorter than a length of the first processing area in the first direction, the second processing area comprises a plurality of band areas, and a length of each of the band areas of the second processing area is shorter than a length of the second processing area in the first direction, wherein the transmission unit transmits a plurality of units of band data to the first processing unit, and wherein during a period extending from a start of the transmission of the plurality of units of band data to the first processing unit to an end of the transmission of the plurality of units of band data to the first processing unit, the transmission unit transmits at least one unit of band data to the second processing unit.