Fig. 2
From: Image steganography based on color palette transformation in color space
Analyzed RGB cube (a) has more than one color; therefore, it is divided into eight sub-cubes (b-i), but only sub-cubes with at least one color (g–i) were analyzed further, while sub-cubes with no colors (b-f) are not analyzed anymore. Sub-cubes h and i are suitable to embed message as only one color exists. Sub-cube g has more than one color and it has to be divided, but the cube is too small for division and will not be used for message embedding in next iteration