1. An image processing method comprising: (a) receiving an image signal from an image signal input device representing an image, detecting a feature of the image, and analyzing the image signal based on the detected feature of the image; (a1) selectively estimating a depth of the image and obtaining depth distribution information of the image, according to the analysis result; (b) performing segmentation on the image signal according to the analysis result and according to the estimated depth when estimating the depth of the image is performed; and (c) performing image processing, using a computer, on the image signal according to the segmentation result.