Image Processing x 2 Michael Werman The Hebrew University of Jerusalem 1) How to transform a picture with many bits per pixel in order to display it on an device with less bits so that the image is visually nice. Abstract We present a new method for rendering high dynamic range images on conventional displays. Our method is conceptually simple, computationally efficient, robust, and easy to use. We manipulate the gradient field of the luminance image by attenuating the magnitudes of large gradients. A new, low dynamic range image is then obtained by solving a Poisson equation on the modified gradient field. Our results demonstrate that the method is capable of drastic dynamic range compression, while preserving fine details and avoiding common artifacts, such as halos, gradient reversals, or loss of local contrast. The method is also able to significantly enhance ordinary images by bringing out detail in dark regions. 2) How does a digital camera see color and what should we do about it. Abstract We present a color model that is image dependant and useful for overcoming the nonlinearity of digital cameras. The model is suitable for color image segmentation and enables one to easily manipulate and enhance the colors of an image.