An image forming apparatus (10, 10A) comprising: an image forming unit that forms an image on a medium with image forming liquid including at least ink; a tension applying section (34, 58) that applies tension to the medium; a transport unit (30, 56) that allows the medium to which the tension is applied by the tension applying section and to which the image is printed by the image forming unit to be transported relative to each other; an image data acquisition section that acquires image data; an image forming liquid-application amount-information acquisition unit acquiring image forming liquid-application amount-information that is information about the amount of the applied image forming liquid calculated on the basis of the image data acquired by the image data acquisition section; a tension-information acquisition unit acquiring tension information that is information about the tension applied to the medium by the tension applying section; an elastic modulus acquisition unit that acquires an elastic modulus of the medium to which the image forming liquid is applied, the elastic modulus of the medium being calculated using the image forming liquid-application amount-information acquired by the image forming liquid-application amount-information acquisition unit; a Young's modulus storage section that stores a Young's modulus for each amount of the image forming liquid to be applied to the medium, wherein the elastic modulus acquisition unit acquires the elastic modulus that is calculated using a Young's modulus corresponding to the amount of the applied image forming liquid acquired by the image forming liquid-application amount-information acquisition unit; a medium deformation amount-calculation unit that calculates the amount of deformation of the medium between a state where the tension is applied by the tension applying section (34,58) and a state where the tension is not applied, using the tension information acquired by the tension-information acquisition unit and the elastic modulus of the medium acquired by the elastic modulus acquisition unit; an image conversion section that converts the image data, which is acquired by the image data acquisition section, into converted image data, which represents a converted image to be formed on the medium in a state where the tension is applied by the tension applying section, on the basis of the amount of deformation of the medium calculated by the medium deformation amount-calculation unit; and an image formation control section that controls image formation, which is performed by the image forming unit on the medium to which the tension is applied by the tension applying section and which is transported relative to the image forming unit by the transport unit (30,56), on the basis of the converted image data. an image forming unit that forms an image on a medium with image forming liquid including at least ink; a tension applying section (34, 58) that applies tension to the medium; a transport unit (30, 56) that allows the medium to which the tension is applied by the tension applying section and to which the image is printed by the image forming unit to be transported relative to each other; an image data acquisition section that acquires image data; an image forming liquid-application amount-information acquisition unit acquiring image forming liquid-application amount-information that is information about the amount of the applied image forming liquid calculated on the basis of the image data acquired by the image data acquisition section; a tension-information acquisition unit acquiring tension information that is information about the tension applied to the medium by the tension applying section; an elastic modulus acquisition unit that acquires an elastic modulus of the medium to which the image forming liquid is applied, the elastic modulus of the medium being calculated using the image forming liquid-application amount-information acquired by the image forming liquid-application amount-information acquisition unit; a Young's modulus storage section that stores a Young's modulus for each amount of the image forming liquid to be applied to the medium, wherein the elastic modulus acquisition unit acquires the elastic modulus that is calculated using a Young's modulus corresponding to the amount of the applied image forming liquid acquired by the image forming liquid-application amount-information acquisition unit; a medium deformation amount-calculation unit that calculates the amount of deformation of the medium between a state where the tension is applied by the tension applying section (34,58) and a state where the tension is not applied, using the tension information acquired by the tension-information acquisition unit and the elastic modulus of the medium acquired by the elastic modulus acquisition unit; an image conversion section that converts the image data, which is acquired by the image data acquisition section, into converted image data, which represents a converted image to be formed on the medium in a state where the tension is applied by the tension applying section, on the basis of the amount of deformation of the medium calculated by the medium deformation amount-calculation unit; and an image formation control section that controls image formation, which is performed by the image forming unit on the medium to which the tension is applied by the tension applying section and which is transported relative to the image forming unit by the transport unit (30,56), on the basis of the converted image data.