PURPOSE: To share an image reproducing device and an image filing device even in the case that accumulating phosphor sheets have different sizes by making the reading density common to the accumulating phosphor sheets having the different sizes and making a lowering ratio larger as the size of the sheet gets larger so that the density of a picture element may be lowered.

CONSTITUTION: Even when the sizes of the accumulating phosphor sheets being a read object are variously different, radiograph information is read by making the reading density common to them. On the other hand, a processing that the density of the picture element is lowered by making the lowering ratio larger as the size of the sheet becomes larger is performed to an obtained image signal. Namely, by making the reading density common, it is unnecessary to change the scanning speed of excitation light. The larger the size of the accumulating phosphor sheet is, the larger the number of read picture elements becomes. However, the number of the picture elements is made constant or an approximate state thereto is obtained regardless of the size of the sheet by setting the lowering ratio and performing the processing for lowering the density of the picture element to the image signal. Thus, this method is allowed to cope with the narrow allowable width of the number of picture elements of the image reproducing device and the filing device.