This paper proposes a new approach to detect rotated objects at distinct angles using
the Viola-Jones detector. The use of additional Integral Images makes an approximation the
Haar-like features for any given angle. The proposed approach uses di erent types of Haar-like
features, including features that compute areas at 45o, 26.5o and 63.5o of rotation. Given a
trained classi er (using normal features) a conversion is made using a pair of features so an
equivalent value is computed for any angle. This conversion is only an approximation, but
the errors are constrained and they would have limited impact on the nal accuracy of the
classi er. We discuss the sources of errors in the computation of the Haar-like features and
show through experiments that in natural images the errors are often negligible.
