In the HSV color space, hue is used to distinguish colors, saturation is the percentage of white light added to a pure color, and value refers to perceived light intensity.36 It is known that the method of calculating HSV spatial components might affect both recognition performance and computational efficiency. From practical experience, we quantify the HSV space component in unequal intervals. The quantization scheme is shown as Display Formula
(1)Here, based on a color model derived from substantial analysis, we divide hue into 16 parts. Saturation and value are divided into four parts each. Then an HSV histogram is generated using quantified hue (), saturation (), and value () as Display Formula
(2)where is the quantified series of and is the quantified series of . Here, we set . Then Display Formula
(3)Finally, we concatenate the histogram and obtain a 256-dimensional vector for each patch, which is exactly an atom of the dictionary. Thus, we obtain an overcomplete dictionary , which is the union of two low-dimensional subdictionaries, i.e., the landslide subdictionary and the background subdictionary spanned by landslide training samples and background training samples , respectively.