In this paper a method is proposed to discriminate natural and manmade scenes of similar depth. Increase in image depth leads to increase in roughness in manmade scenes; on the contrary natural scenes exhibit smooth behavior at higher image depth. This particular arrangement of pixels in scene structure can be well explained by local texture information in a pixel and its neighborhood. Our proposed method analyses local texture information of a scene image using texture unit matrix. For final classification we have used unsupervised learning using Self Organizing Map (SOM). This technique is useful for online classification due to very less computational complexity.