Hough Transform (HT) has been widely used for object detection in digital images, but it requires long execution time and high computational complexity. Therefore Incremental Hough Transform (IHT) was proposed to reduce requirements of Standard Hough Transform (SHT). IHT reducedexecution time and computational complexity by applying parallel, pipeline architectures and approximations. However, IHT has the accumulated errors due to cosine and sine approximation from SHT. It makes that IHT needs to conjugate SHT. In order to reduce the number of SHT conjugation, we propose a Bidirectional Incremental Hough Transform(BIHT)