## 1 Introduction  
As a new display technology, LED displays are widely used in public as information displays, cluster displays, outdoor media, and in other fields, including financial information displays of the stock exchange, passenger guidance information displays at ports and stations, dynamic information displays for airport flights, road traffic information displays, information releases for large exhibitions, command centers, etc. [1]. Modulating the flicker frequency of the LED display's light-emitting unit element (i.e., display pixel) above the flicker fusion threshold can enable the LED display to display normally while emitting high-speed visible light communication (VLC) signals that are imperceptible to the human eye for covert information transmission, thus providing the LED display with the dual-use function of displaying and broadcasting information simultaneously [2; 3; 4; 5]. At the same time, the VLC signal emitted by the LED display can be received by the complementary metal oxide semiconductor (CMOS) image sensor, which can recover the transmitted information. At present, many portable mobile electronic devices (i.e., smartphones) are equipped with high-resolution CMOS cameras, which can easily build up an LED display-camera communication (LED-DCC) system and realize some novel industry applications [4]; for example, real-time road information broadcasting and reception based on LED traffic lights, invisible advertising pushing based on airport flight dynamic displays, etc., which can provide mobile value-added service functions for LED displays. Unlike conventional optical camera communication (OCC) [6], the optical signal transmitting element of LED-DCC is the LED display pixel point, which is constrained by display conditions and has the characteristics of a small, single-point, light-emitting area and low-signal power, limiting the communication performance of LED-DCC. Based on the potential application prospects of DCC, there has been some research carried out on DCC systems that make a trade-off between the visual experience and communication performance, including the data rate and bit error rate (BER) [7]. In 2016, [PERSON], [PERSON] et al. proposed a spatially adaptive embedding scheme, TextureCode, to achieve flicker-free communication by exploiting the low sensitivity of the human visual system in the texture-rich region, and also proposed a TextureCode-Hybrid scheme, which is a mix of the HiLight and TextureCode schemes under plain and high-texture blocks, achieving a higher transmission rate [8]. RainBar [9] features a code locator detection and localization scheme to allow flexible frame synchronization and accurate code extraction. ChromaCode [10] proposed an outcome-based adaptive embedding scheme, which adapts to both pixel lightness and frame texture. In 2019, RU codes and vRU codes [11] were proposed to combine 2D barcodes with images and videos for unobtrusive DCC at high data rates, based on the properties of the human visual system and the concept of a complementary framework. In the DaViD system [12], [PERSON], [PERSON] et al. addressed the spatial synchronization problem by utilizing localization patterns for detecting the modulation area and a separate optimization of columns and rows for data resampling. Based on that, clean data frames can be reconstructed by using a slight temporal oversampling. In 2021, [PERSON] et al. proposed a DCC method based on spatial frequency modulation by hiding data bits through the modulation of the high spatial frequency on the discrete cosine domain, and \"0\" and \"1\" bits are embedded in the transition between blurred and sharpened frames [13]. In 2022, [PERSON], [PERSON] et al. proposed a frame recovery method based on differential modulation to solve the synchronization problem for the invisible DCC system, in which the original display frames are recovered from asynchronous recordings in the receiver [4].