In this paper, the potential benefits of image sensor three-Dimensional integration are evaluated. A case study on a High Dynamic Range (HDR) image sensor is done with performance comparison of the architecture developed for the 3D technology and the one used for the 2D integration. It specifically focuses on the power consumption where it shows that the 3D architecture can bring a decrease of the power consumption of a factor of at least 2.5 while keeping the same image sensor performances and even improving image quality.