A method for detecting one or more activities associated with a human, the method comprising processor implemented steps of: capturing at least one image using a motion sensing device, wherein the at least one image comprises a plurality of pixels having gray scale information and a depth information, and wherein the gray scale information comprises intensity of each pixel corresponding to a plurality of objects in the at least one image, and wherein the depth information comprises a distance information between each object and the motion sensing device; analyzing each pixel to identify one or more candidate objects of a plurality of objects in the at least one image by, comparing the gray scale value of each pixel with a pre-defined gray scale value, replacing a subset of the pixels having the gray scale value less than the pre-defined gray scale value with 0 and a remaining subset of the pixels with 1 in order to derive a binary image corresponding to the at least one image, and determining the subset as the one or more candidate objects in the binary image; performing a connected component analysis on the binary image in order to detect a candidate object of the one or more candidate objects as a human; retrieving the depth value associated with each pixel corresponding to the candidate object from a look-up table; and detecting an activity of the candidate object by using the depth value, wherein the activity of the candidate object is detected as walking when difference of an average depth value of one or more pixels in the image and the average depth value of the one or more pixels in a subsequent image of the image is greater than a predefined threshold value, and the activity of the candidate object is detected as standing or sitting or sleeping when difference of the average depth value of the one or more pixels in the image and the average depth value of the one or more pixels in the subsequent image of the image is less than the predefined threshold value, wherein the one or more pixels in the image and the one or more pixels in the sub-sequent image are associated with the candidate object. capturing at least one image using a motion sensing device, wherein the at least one image comprises a plurality of pixels having gray scale information and a depth information, and wherein the gray scale information comprises intensity of each pixel corresponding to a plurality of objects in the at least one image, and wherein the depth information comprises a distance information between each object and the motion sensing device; analyzing each pixel to identify one or more candidate objects of a plurality of objects in the at least one image by, comparing the gray scale value of each pixel with a pre-defined gray scale value, replacing a subset of the pixels having the gray scale value less than the pre-defined gray scale value with 0 and a remaining subset of the pixels with 1 in order to derive a binary image corresponding to the at least one image, and determining the subset as the one or more candidate objects in the binary image; comparing the gray scale value of each pixel with a pre-defined gray scale value, replacing a subset of the pixels having the gray scale value less than the pre-defined gray scale value with 0 and a remaining subset of the pixels with 1 in order to derive a binary image corresponding to the at least one image, and determining the subset as the one or more candidate objects in the binary image; performing a connected component analysis on the binary image in order to detect a candidate object of the one or more candidate objects as a human; retrieving the depth value associated with each pixel corresponding to the candidate object from a look-up table; and detecting an activity of the candidate object by using the depth value, wherein the activity of the candidate object is detected as walking when difference of an average depth value of one or more pixels in the image and the average depth value of the one or more pixels in a subsequent image of the image is greater than a predefined threshold value, and the activity of the candidate object is detected as standing or sitting or sleeping when difference of the average depth value of the one or more pixels in the image and the average depth value of the one or more pixels in the subsequent image of the image is less than the predefined threshold value, wherein the one or more pixels in the image and the one or more pixels in the sub-sequent image are associated with the candidate object.