The invention provides a method for depth estimation in image or video obtained from a distorting medium. In the method, a pixel blurriness map is calculated. A rough depth map is then determined from the pixel blurriness map while assuming depth in a small local patch is uniform. The rough depth map is then refined. The method can be implemented in imaging systems, such as cameras or imaging processing computers, and the distorting medium can be an underwater medium, haze, fog, low lighting, or a sandstorm, for example. Preferred embodiments determined the blurriness map by calculating a difference between an original image and multi-scale Gaussian-filtered images to estimate the pixel blurriness map.