A digital X-ray image processing apparatus for exposing an X-ray transmitted through an object onto a photostimulable phosphor plate, for scanning the photostimulable phosphor plate by using an excitation beam to obtain an X-ray image, and for reading the X-ray image. The digital X-ray image processing apparatus includes an image storage unit for storing the X-ray image used for an actual read when diagnosing the object and a histogram storage unit for storing a standard histogram of the X-ray image. The standard histogram is formed by an intensity and frequency of the X-ray. Also provided is a first monitor unit for displaying the standard histogram read out from the histogram storage unit and a read conditions determination unit for determining actual read conditions of the X-ray image based on a latitude of the intensity of the X-ray in the standard histogram.