Multi-view video transmission poses great challenges because of its data size and dimension. Therefore, how to design efficient 3D scene representations and coding (of luminance and geometry) has become a critical research topic. Recently, the graph-based representation (GBR) is introduced, which provides a lossless compression of multi-view geometry by connecting informative pixels among views. This representation has been shown as a promising alternative to the classical depth-based representation, where the view synthesis accuracy is hard to control. In this work, we study the luminance compression under GBR, which is not well considered in existing literature. With a proper structural reformulation, we show that the graph-based transform can be applied on the GBR paradigm, hence better extracting the correlation among pixels along graph connections. Moreover, we extend the popular SPIHT coding scheme to further improve coding efficiency. The experimental results show that our method leads to better RD coding performance as compared the classical luminance coding algorithms.