1. A method for detecting an object in a scene, comprising the steps of: determining an active set of window positions from depth data, wherein the depth data are acquired by a sensor, and for each window position in the active set of window positions further comprising the steps of; assigning a window size from the depth data; selecting a current window from the active set of window positions; extracting a joint feature from the depth data and texture data for the current window w, wherein the texture data are acquired by a camera; classifying the joint feature to detect the object, wherein the classifier is trained with joint training features extracted from training data including training depth data and training texture data acquired by the sensor and camera respectively, and; updating the active set of windows position before processing a next current window, wherein the steps are performed in a processor.