Representing four-primary-color image based on three-primary-color channels

To overcome the problem that images captured by the current imaging system with the multi-primary-color image sensor cannot be transmitted under the three-primary-color channel, as well as the wide color gamut display system using multi-primary color filters or backlight does not have multi-primary-color image contents, this paper presents a method transmitting four-primary-color images only with the data amount of the YUV format. The quadrilateral constituted by four-pri-mary colors is decomposed into two triangles so that one can represent a composite color uniquely using the corresponding three-primary colors. If a composite color lies in the RGB triangle, it can be encoded according to the standard YUV format. Otherwise, it can be encoded in a non-standard YUV format. The difference between standard YUV format and non-standard YUV format enables the decoder to blindly identify the source of the YUV data stream. In this way, the display can render the color in question using three corresponding primaries. The experimental results show that the proposed image coding method can completely deliver the four-primary-color image signals using the YUV data amount. Decoder can identify the source of the YUV data stream absolutely. Using JPEG compression algorithm to test the YUV sequence, the compression ratio is increased by 0.07 similar to 0.59 compared to the RGB three-primary-color system. The gamut coverage far exceeds the Pointer gamut, even is closer to the visible gamut of the human eye.