1. A medical image processing apparatus comprising: an image acquiring unit configured to acquire a plurality of medical images obtained by imaging an identical region of an object under different radiographing conditions; a relation acquiring unit configured to acquire a correlation between a signal value and a radiographing condition at a pixel at a same position in the plurality of medical images; a condition acquiring unit configured to acquire a virtual radiographing condition that is different from the radiographing conditions of the plurality of medical images; a generating unit configured to generate a diagnosis image by acquiring a signal value of each pixel based on the correlation and the virtual radiographing condition; a display condition acquiring unit configured to acquire a window width value and a window level value for displaying one medical image of an identical cross section of the object; and a display control unit configured to cause a display unit to display the diagnosis image based on the window width value and window level value acquired by the display condition acquiring unit.