## 3 System Model  
The system model of the DeepCCB-OCC system is shown in Figure 1. At the transmitting end, the binary data are encoded into a color barcode, and consecutive packets are sent through the display. In order for data to be encoded in a color form, color mapping using a pre-designed color constellation diagram is required. The pilot and data symbols are then mapped to designated color values and consist of data packets. All symbols in the packet are composed of complementary color pairs, and the display shows the symbols composed of complementary color pairs in the designated color barcode area in successive image frames. The receiving end captures the display area using a rolling shutter camera, and the captured image is stored in the image frame buffer. At this time, the color barcode area appears white to the human eye, but continuous color change is observed in the color barcode area. When a color barcode area is detected by using a deep learning model on the stored images, color barcode images are stored in an image list. Then, a deep learning-based pilot symbol detection process for continuous packet synchronization is performed, identifying the start point of each packet. When synchronization is complete, data within each packet are consecutively decoded through the data symbol detector using deep learning. To transmit information using the DeepCCB-OCC system, it is necessary to match the transmission symbol and the color value. The complementary color relationship of the DeepCCB-OCC system was constructed using the hue circle shown in Figure 2. Primary and complementary colors are located 180 degrees from each other on the hue circle. For primary colors (red, green, and blue), the complementary colors are cyan, yellow, and magenta. When primary and complementary colors are added, the R, G, and B channel values are 255, resulting in white. When the primary and complementary colors appear in succession through the display's fast refresh rate, the human eye sees the combination of the two colors as white. This allows additional information that is unobtrusive to the human eye to be transmitted through the display. As can be seen in the figure, eight symbols constitute the hue circle, and each symbol consists of three bits. Grey coding is used to minimize the bit error rate in the decoding process. Each symbol is expressed as the intensity value of the red (R), green (G), and blue (B) channels, and the color value for each channel for the eight symbols used in CCB-OCC is shown in Figure 2.  
When the proposed technique transmits data through the display, color barcodes must be continuously configured so that the primary color and the complementary color are paired. If the R, G, B-encoded symbols are transmitted, the actual data stream is RR'GG'BB', where R, G, and B denote the encoded symbols and R', G', and B' denote the complementary colors. The receiver uses the image captured while filming the display using a rolling shutter camera. Theoretically, when capturing the image at half the speed of the display's output, a color barcode formed by pairs of primary and complementary colors appears as a single captured image. As shown in Figure 1, for example, if the transmitter's screen refresh rate is 60 Hz, and the receiving end captures it at 30 fps, the six transmitted frames (R, R', G, G', B, B') appear at the receiver as three incoming images, RR', GG', and BB', but are perceived as a white bar to the human eye. Figure 1: The system model for DeepCCB-OCC. Figure 2: The color constellation for Complementary Color Barcode-based OCC. Data-encoded color barcode symbols are transmitted in the form of packets, as shown in Figure 3. Transmission packets used in CCB-CCC consist of pilot symbols and data symbols, with each symbol composed of complementary color pairs. The pilot symbol, used for synchronization and channel estimation, is designed as six image frames in the form RR'GG'BB'.