Various aspects of an image processing system and method for object boundary smoothening for image segmentation, includes receipt of a user input to enable selection of a foreground object in an input color image. A frequency of occurrence of foreground pixels with respect to background pixels is determined for a plurality of pixels within a local pixel analysis window. The local pixel analysis window is positioned in a first region of the input color image to encompass at least a first pixel to be validated for a correct mask value. A first cost value and a second cost value is selected for the first pixel based on the determined frequency of occurrence of the foreground pixels. An object boundary is generated for a portion of the foreground object based on the selected first cost value and the second cost value for the first pixel.