We present a simple and effective tone mapping operator, that preserves visibility and contrast impression of high dynamic range images. The method is conceptually simple, and easy to use. We use a s-function type operator which takes into account both the global average of the image, as well as local luminance in the immediate neighborhood of each pixel. The local luminance is computed using a median filter. It is seen that the resulting low dynamic range image preserves fine details, and avoids common artifacts such as halos, gradient reversals or loss of local contrast.