"codemeta:abstract": "We call RGB cube the three dimensional representation of the colors of a digital image in RGB space. It has been observed that 2D structures predominate in the color cube. They are qualitatively explained by two main causes: image blur and texture. In this article a filtering algorithm, the Local Linear Projection (LLP2), is used to smooth the 3D color distribution and to reveal the underlying 2D structures of the color clusters.",