An image processing apparatus, comprising: an interface configured to acquire image data from a removable drive; a hard disk drive; a rendering unit configured (a) to generate intermediate data from the image data and store the intermediate data in the hard disk drive, wherein the intermediate data includes an analyzing result of the image data and (b) to generate bitmap image data on the basis of the intermediate data; and a data handling unit configured (a) to estimate a size of the intermediate data on the basis of the image data, and (b) to select one of a first rendering mode and a second rendering mode judging on the basis of a size of a sum of the image data and the estimated size of the intermediate data; wherein in the first rendering mode, the data handling unit is further configured to make a copy of the image data and store the copy in the hard disk drive and to cause the rendering unit to generate the bitmap image data from the image data stored in the hard disk drive; and in the second rendering mode, the data handling unit is further configured to cause the rendering unit to generate the bitmap image data from the image data stored in the removable drive and wherein the data handling unit is further configured to select the first rendering mode if a free area size of the hard disk drive is larger than a sum of the size of the image data and the estimated size of the intermediate data, or wherein the data handling unit is further configured to select the first rendering mode if a sum of the size of the image data and the estimated size of the intermediate data is less than a predetermined threshold value. an interface configured to acquire image data from a removable drive; a hard disk drive; a rendering unit configured (a) to generate intermediate data from the image data and store the intermediate data in the hard disk drive, wherein the intermediate data includes an analyzing result of the image data and (b) to generate bitmap image data on the basis of the intermediate data; and a data handling unit configured (a) to estimate a size of the intermediate data on the basis of the image data, and (b) to select one of a first rendering mode and a second rendering mode judging on the basis of a size of a sum of the image data and the estimated size of the intermediate data; wherein in the first rendering mode, the data handling unit is further configured to make a copy of the image data and store the copy in the hard disk drive and to cause the rendering unit to generate the bitmap image data from the image data stored in the hard disk drive; and in the second rendering mode, the data handling unit is further configured to cause the rendering unit to generate the bitmap image data from the image data stored in the removable drive and wherein the data handling unit is further configured to select the first rendering mode if a free area size of the hard disk drive is larger than a sum of the size of the image data and the estimated size of the intermediate data, or wherein the data handling unit is further configured to select the first rendering mode if a sum of the size of the image data and the estimated size of the intermediate data is less than a predetermined threshold value.