An image processing apparatus comprising: base material information acquisition means for acquiring base material information including at least (i) yarn type information for specifying a quality of warp and weft as information indicating the quality of the fiber in cloth which is a medium to be printed and (ii) weave type information indicating the type of weave and thickness information indicating a thickness of a yarn; image acquisition means for acquiring image data of a pattern to be printed on the cloth ; and pretreatment liquid image generation means for generating a pretreatment liquid image that indicates a pretreatment liquid application pattern defining a pretreatment liquid application position where a pretreatment liquid including a functional material for preventing wetting and spreading of ink in the cloth is applied and a pretreatment liquid non-application position where the application of the pretreatment liquid is limited, on the basis of the base material information and the image data , characterised in that the pretreatment liquid image generation means includes: function determination means for determining a function used to calculate an application direction and range of the pretreatment liquid on the basis of the base material information ; and arithmetic processing means for calculating the pretreatment liquid application position and an amount of pretreatment liquid applied which correspond to the image data , using the function determined by the function determination means . base material information acquisition means for acquiring base material information including at least (i) yarn type information for specifying a quality of warp and weft as information indicating the quality of the fiber in cloth which is a medium to be printed and (ii) weave type information indicating the type of weave and thickness information indicating a thickness of a yarn; image acquisition means for acquiring image data of a pattern to be printed on the cloth ; and pretreatment liquid image generation means for generating a pretreatment liquid image that indicates a pretreatment liquid application pattern defining a pretreatment liquid application position where a pretreatment liquid including a functional material for preventing wetting and spreading of ink in the cloth is applied and a pretreatment liquid non-application position where the application of the pretreatment liquid is limited, on the basis of the base material information and the image data , characterised in that the pretreatment liquid image generation means includes: function determination means for determining a function used to calculate an application direction and range of the pretreatment liquid on the basis of the base material information ; and arithmetic processing means for calculating the pretreatment liquid application position and an amount of pretreatment liquid applied which correspond to the image data , using the function determined by the function determination means . function determination means for determining a function used to calculate an application direction and range of the pretreatment liquid on the basis of the base material information ; and arithmetic processing means for calculating the pretreatment liquid application position and an amount of pretreatment liquid applied which correspond to the image data , using the function determined by the function determination means . <EOS>