This paper presents a document skew and orientation de- tection technique. The proposed technique estimates docu- ment skew and orientation based on the observation that text images normally hold a large amount of equidistant in- terline spacings and the number of character ascenders is statistically much larger than that of character descenders. Given a document image with arbitrary skew and orien- tation, white run histograms are first constructed through scanning documents in horizontal and vertical directions. Document skew is then estimated by using the white runs that exactly span the interline spacing. Lastly, document orientation is determined according to the numbers of char- acter ascenders and descenders, which are detected by us- ing the white runs that cross the interline spacing and lie over character ascenders and descenders. Experiments show that the proposed technique is fast, accurate, and ca- pable of detecting arbitrary document skew and orientation.