A method and apparatus for HDMI video lighting synchronization that integrates black border detection and HDR knee compression

Abstract

This invention discloses an HDMI video lighting synchronization method and apparatus that integrates black border detection and HDR knee compression, relating to the fields of video signal processing and intelligent lighting control technology. The method detects black borders and subtitles in the video frame and generates a mask to limit the color sampling range, focusing the sampling on the main subject. It adaptively determines knee compression parameters to maintain brightness levels. By statistically analyzing color and brightness according to positional weights and distributing them to each light fixture, it establishes a unified frame reference and completes timing calibration. Simultaneously, it provides an optional viewing-friendly stabilization mechanism, converging color sampling and constraining changes in lights near subtitles when there are significant changes in subtitles or edges. The technical effects are: color sampling results focus on the main subject; subtitles and black borders no longer cause color casts; transitions between shots are smooth; and group control switching is consistent. The system can switch between prioritizing viewing experience and prioritizing latency as needed, achieving real-time synchronization without disrupting the viewing experience.

Description

Technical Field

[0001] This invention relates to the field of intelligent lighting and video signal processing, and more specifically, to an HDMI video lighting synchronization method and apparatus that integrates black border detection and HDR knee compression. Background Technology

[0002] Video signal processing and intelligent lighting control technology is primarily used to convert the color and brightness information of video images into ambient lighting effects, thereby enhancing the user's immersive experience. This type of technology can be widely applied in scenarios such as home theaters, gaming, and stage performances. By adjusting the color and brightness of lights in real time, it allows users to experience a stronger sense of immersion and atmosphere during viewing or interaction. With the increasing popularity of high-definition television and HDR video, users' demand for a high degree of consistency between lighting and image quality is constantly increasing, highlighting the growing importance of this technology.

[0003] The existing technology has the following shortcomings:

[0004] Existing intelligent lighting synchronization methods fail to effectively remove black borders and bottom subtitles from movie mailboxes when processing video images. Sampling falls into invalid areas, causing subtitle-driven color shifts and lowering overall brightness due to black areas, directly interfering with the viewing experience. They lack effective mechanisms for HDR brightness mapping, often resorting to direct discarding or linear compression, resulting in highlight clipping and shadow compression, leading to inconsistencies between lighting levels and the overall image. Furthermore, they lack viewer-friendly stabilization and calibration strategies. There are no constraints on brightness change rate and hue shift when subtitles or edges change rapidly, and after networking, there is a lack of frame-level unified benchmarks and multi-protocol timing calibration. Additionally, there is a lack of configurable view-first and latency-first modes, making it impossible to enable constraints to suppress disturbances when stability is needed, or to disable constraints to further compress link latency when not needed.

[0005] To address the above problems, this invention proposes a solution. Summary of the Invention

[0006] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide an HDMI video lighting synchronization method and apparatus that integrates black border detection and HDR knee compression, in order to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for synchronizing HDMI video lighting by integrating black border detection and HDR knee compression includes:

[0009] After receiving HDMI video, the system forms a display pass-through path and an analysis mirror path. The two paths share the same frame order, thus obtaining a unified frame time reference.

[0010] The current frame of the mirror path is downsampled and linearized in color. A linear brightness scale is obtained based on the transmission curve of the source image, and a normalized spatial scale from pixel to lamp is established according to the lamp installation position.

[0011] Black border and subtitle detection are performed on the downsampled frame to generate a continuously valued mask, and the main area and viewing-sensitive area are defined based on the mask.

[0012] A color sampling window is established around each lamp in the main area to generate a region weight (ROI weight) for pixel weighted statistics. The region weight is combined with the mask to obtain a comprehensive weight, and the representative color and representative brightness are calculated accordingly.

[0013] Based on the brightness distribution of the main area, determine the knee point parameters and exponential parameters, perform knee point compression to obtain the target brightness, and project it onto the achievable color gamut boundary of the lamp according to the principle of minimum color difference while keeping the brightness and hue unchanged, to obtain the target color.

[0014] After smoothing the target color and brightness over time and limiting the rate of change, a group control formula is generated according to a unified effective time and distributed to all lamps to achieve synchronous switching within the same frame.

[0015] The system can choose to enable a viewing-friendly stabilization mechanism. When this mechanism is enabled, it further restricts and smooths the target brightness and target color to reduce flicker and color cast. When this mechanism is disabled, it does not perform such restrictions and smoothing to shorten latency.

[0016] In a preferred embodiment, the display pass-through path and the analysis mirror path read a shared frame sequence in a stable time slot during video synchronization, and the shared frame sequence serves as a unified frame time reference for subsequent processing steps.

[0017] In a preferred embodiment, the downsampling is performed in the order of first performing anti-aliasing processing and then mean pooling, the color linearization is performed by the inverse transformation of the input transfer curve, and the linear luminance scale remains consistent during the representative quantity statistics and color mapping process.

[0018] In a preferred embodiment, the black border detection is based on the average brightness and height ratio of the upper and lower edge bands to give a judgment result, and the subtitle detection is based on the brightness comparison and connectivity of the bottom band to give a judgment result. The thresholds of the two are determined by the content adaptive rule. The mask is averaged by local windows to form a continuous value weight and directly participates in subsequent statistics.

[0019] In a preferred embodiment, the region weight is a monotonically decreasing function under the normalized spatial scale from pixel to lamp, the decay rate is controlled by a single decay coefficient, and the overall weight is the product of the region weight and the mask weight.

[0020] In a preferred embodiment, the knee point parameter is determined based on the quantile of the intra-frame brightness distribution, and the exponent parameter is determined based on the degree of brightness dispersion; the color gamut constraint only scales the chromaticity while keeping the target brightness and hue unchanged, and projects it onto the achievable color gamut boundary of the luminaire according to the principle of minimum color difference.

[0021] In a preferred embodiment, the time smoothing process adopts a first-order recursion and sets smoothing coefficients for the three control channels respectively, while setting a single-frame change rate limit; the group control command includes a unified effective time and performs alignment compensation when it is issued, and sends it through multicast or equivalent synchronization method so that all lamps switch synchronously under the same frame time reference.

[0022] In a preferred embodiment, the system introduces a sensitive coverage ratio in the viewing-friendly stability mechanism to quantify the degree to which the color picking window is interfered with by subtitles or black borders; performs convergence correction on the target brightness and target color according to the sensitive coverage ratio, and redistributes the brightness in the boundary area of ​​adjacent lights to suppress local abrupt changes caused by high contrast of subtitle strips or edges, thereby improving the consistency and stability of the picture and the lights.

[0023] In a preferred embodiment, the convergence correction involves setting convergence intensities for the target brightness and target color respectively, and adaptively adjusting the correction magnitude according to the sensitive coverage ratio to achieve a smooth transition and visual stability.

[0024] An HDMI video lighting synchronization device that integrates black border detection and HDR knee compression includes:

[0025] The HDMI receiver and pass-through unit is used to complete capability negotiation with the display, establish a display pass-through path and analyze the mirror path, and provide a shared frame order as a frame time reference.

[0026] The video downsampling and preprocessing unit is used to downsample and linearize the colors of frames in the analysis mirror path, and output a linear brightness scale and a normalized spatial scale from pixel to lamp.

[0027] The black border detection and active area clipping unit is used to detect black borders and subtitles on the downsampled frame and output a mask for masking or weight reduction.

[0028] The ROI mapping and color statistics unit is used to establish a color sampling window around each lamp, generate regional weights with decreasing distance based on the normalized spatial scale, and synthesize a comprehensive weight with the mask to calculate the representative brightness and representative color of the lamp.

[0029] The HDR color mapping unit is used to set a tone mapping function with at least one knee point according to the intra-frame brightness distribution, perform knee point compression on the representative brightness, constrain the representative color to the achievable color gamut and brightness range of the lamp, and output the target brightness and target color.

[0030] The sensitive area constraint and correction unit is used to converge and correct the target brightness and target color according to the sensitive coverage ratio within the color sampling window, and to redistribute the brightness in the boundary area of ​​adjacent lamps to suppress local abrupt changes caused by high contrast of subtitle strips and edges.

[0031] The lighting recipe generation and group control output unit is used to perform time smoothing processing on the target brightness and target color and set the rate of change constraint, generate a group control command containing a unified effective time and send it to all lamps to achieve synchronous switching.

[0032] The technical effects and advantages of the HDMI video lighting synchronization method and device that integrates black border detection and HDR knee compression as described in this invention are as follows:

[0033] This invention establishes direct and mirror links at the video input end to ensure that display and processing share a unified frame time reference; it generates masks through black border and subtitle detection to concentrate color sampling on the main area, avoiding color shift and brightness reduction caused by subtitles and black borders; it maintains brightness levels through adaptive knee compression to keep the light output consistent with the image; it smooths the transition between adjacent lights and avoids abrupt changes during shot switching through ROI weight mapping and brightness redistribution; and it uses an optional viewing-friendly stabilization mechanism to converge color sampling and constrain brightness and hue changes when subtitles are obvious or edge contrast is strong, reducing flicker and jumps; when this mechanism is turned off, link latency is further reduced, thus flexibly choosing between viewing experience priority and latency priority to achieve a stable real-time synchronization effect. Attached Figure Description

[0034] Figure 1 This is a flowchart of the method of the present invention;

[0035] Figure 2 This is a structural diagram of the platform module of the present invention;

[0036] Figure 3 This is a time-series swimlane diagram of the present invention;

[0037] Figure 4 A comparison chart of the lighting response when the movie-friendly and stable mechanism is enabled and disabled. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should all fall within the protection scope of the present invention.

[0039] This invention provides an HDMI video lighting synchronization method that integrates black border detection and HDR knee compression. The system is designed for real-time lighting synchronization, aiming to stably map the main subject image onto the lighting output within a strict latency budget, reduce color shift caused by subtitles, avoid black borders in the mailbox that lower overall brightness, and ensure smooth transitions during scene changes. Simultaneously, the system incorporates a viewer-friendly stabilization mechanism that can be enabled or disabled based on scene. When subtitles are prominent or have strong edge contrast, the color sampling range converges to the main subject area, reducing the weight of subtitle strips and their neighbors. At the same time, brightness change rate constraints and hue shift constraints are applied to lights near subtitles, keeping changes between the same frame and adjacent frames within a threshold and forming a gradual transition along spatial distance, preventing lighting from competing for screen space from the source. Disabling this mechanism further reduces link latency, thus meeting the requirement for extremely low latency. (Refer to...) Figure 1 , Figure 1 The method flowchart of the present invention specifically includes the following steps:

[0040] In step S101, the system sends the input HDMI video signal to the display end as is on one side, and mirrors it to the system's processing flow on the other side. Both share the same clock and frame order, forming a low-latency and standardized input reference. The system first receives the HDMI video signal. The HDMI video signal consists of consecutive frames, each frame composed of pixel code values, and carries descriptive information explaining the meaning of the pixels, including color gamut standards and transfer curves. Color gamut standards specify the range of displayable colors and primary color coordinates; common standards are BT.709 and BT.2020. Transfer curves specify the correspondence between pixel code values ​​and actual brightness; common types are Gamma, PQ, and HLG. The system simultaneously reads the EDID information to confirm the resolution and frame rate, and retains HDR metadata for subsequent brightness reference unification. The EDID information is capability description data provided by the display device, indicating the supported range of resolution, frame rate, color gamut, and transfer characteristics; the HDR metadata contains feature quantities related to brightness mapping. The system establishes a pass-through link, sending the video signal to the display end as is, and mirroring and splitting the same frame to the analysis end. Simultaneously, the system reads the frame during a stable time slot of video synchronization and generates an effective time reference. The effective time reference is a time stamp of the current input frame, used to align the effective time of subsequent control commands.

[0041] Anti-aliasing filtering and downsampling are performed on the current frame, which reduces the number of pixels and stabilizes subsequent statistics without changing the original image on the display.

[0042] Step S102 involves downsampling the input frame to reduce the number of pixels and stabilize subsequent statistics without altering the original image quality on the display. The system first performs anti-aliasing filtering on the input frame—a preprocessing filter used to suppress high-frequency noise and jagged artifacts when reducing resolution. Then, mean pooling is performed on the scaled grid, averaging the values ​​within local regions to represent the pixel characteristics of that region, resulting in more stable statistical results. Finally, the system generates the reduced frame according to a preset scaling ratio. This reduction process strikes a balance between computational complexity and detail preservation, significantly reducing computational load while maintaining subject edges and brightness levels. Recommended scaling ratio. When the input is At that time, one can obtain The number of pixels is determined by Down to The computational complexity is reduced by more than two orders of magnitude, while still preserving subject detail and brightness levels. In actual operation, the system... arrive Adaptive selection within the range This aims to strike a balance between latency budget and detail preservation. The reduced frame is defined as a downsampled frame and compared with the effective time reference of step S101. One-to-one correspondence.

[0043] To prepare for subsequent calculations and statistics, this step also establishes a unified luminance and spatial scale on the downsampled frame. Let the three-channel code value of the pixel be... , , The inverse transform of the transfer curve is denoted as the function. This function maps code values ​​to linear quantities proportional to the actual light intensity; the linear channel is written as... The system synthesizes linear luminance using linear channel weights within the same color gamut standard, written as... ,in For linear brightness, , , The channel weighting coefficients are determined by the color gamut standard and satisfy... At this point, the different transfer curves were unified onto a directly comparable brightness scale. The system also established coordinates on a spatial scale consistent with the luminaire. In the downsampling frame, the first... Normalized position writing of pixels The range of values ​​is . No. Normalized installation location of the lamp Also defined in Pixels To the light Normalized Euclidean distance writing .

[0044] Step S103: In this step, the black border and subtitles are located on the downsampled frame, and a continuous mask is generated. ,in These are the pixel coordinates defined in S102. The mask is a grayscale weighted map of the same size as the frame, with values... .when Represents pixels Participating in statistics, when Represents pixels This is not included in the statistics. The system first calculates the average brightness and the percentage of continuous height within the narrow bands near the top and bottom edges. Areas with significantly lower brightness and sufficient continuous height are identified as black borders. Then, within the subtitle band at the bottom of the screen, connected regions that are significantly brighter and have stronger contrast than the central reference area are identified as subtitles. The bandwidth and thresholds used for these determinations are provided by adaptive rules; specific values ​​are explained in the implementation examples.

[0045] After obtaining the initial mask, to ensure a smooth transition from black borders or subtitles to the main body area and to remove scattered misjudgments, the system performs a small-window spatial averaging of the mask. This is done by averaging the values ​​of each pixel... Take a small square neighborhood around the pixel, and average the initial mask values ​​within that neighborhood to obtain the pixel value. final mask value After averaging, Re-recorded For later use. To facilitate direct use later, two types of pixel sets are also provided. Main area writing. Writing about sensitive areas of movie viewing ,in and The threshold is adaptive; see the example for specific values.

[0046] Step S104, this step revolves around the normalized position of each lamp. In the main region of the downsampled frame Create a color sampling window and combine it with a mask. The target color and target brightness of each light are calculated using ROI weight mapping. To reflect that closer lights contribute more, the system defines the ROI weight mapping function as follows:

[0047] in For the pixels defined in step S101 To the light The normalized Euclidean distance, with values ​​ranging from 1 to 10. ; This is the weight decay coefficient, with a value range of... The default value is The ROI weight mapping function and the mask are combined into a comprehensive weight. ,in The mask defined in step S103.

[0048] Let the first The linear color vector and linear brightness of each pixel are respectively and Then the lamp The representative color and the representative brightness are as well as ,in For pixels In the lamp The overall weighting. For HDR content, Obtained by inverse transformation of the PQ or HLG transfer curves, it can approximate linear luminance. To ensure a stable distribution of luminaire luminance within the displayable range, the system in the main area... Upper linear brightness Statistical analysis is performed, and its quantile function is given by... The knee point is defined as ,in The selected quantile parameters. The dispersion of brightness is characterized by the coefficient of variation, written as... ,in and They are respectively regions The standard deviation and mean of brightness. Based on the coefficient of variation, the index is defined as... ,in To map the dispersion to an exponential function, its form is further illustrated in the embodiments. The representative luminance is converted to the target luminance of the luminaire through knee compression, written as:

[0049] in Target brightness of lamps and The knee point and exponent are calculated above. The target color is denoted as... ,when When the color gamut exceeds the achievable color gamut of the lamp, it is projected onto the achievable boundary according to the principle of minimum color difference and used as the minimum color difference. This step outputs the target color for each light. and target brightness and steps Defined effective time benchmark Alignment.

[0050] Step S105 is an optional step, and the result obtained in step S104 is... and Based on this, gentle spatial adjustments are made to reduce the impact of subtitles and black borders on color picking, and brightness distribution is coordinated at the boundaries of adjacent lights, thereby maintaining atmosphere and stability without interfering with viewing. Consistent with step S104, the overall pixel weight is determined by the mask. ROI weight mapping function Multiplying them together gives the result, thus ensuring that subsequent corrections are still based on the weight distribution of the main region.

[0051] To demonstrate the visual interference caused by subtitles and black borders, the main area is defined. The sensitive coverage ratio within is:

[0052]

[0053] in For pixels lamp The overall weight, Reflector The degree to which the color picker window is affected by subtitles or black borders. Coverage ratio. The larger the value, the more severe the subtitle or edge interference in the color picker window corresponding to that light.

[0054] according to The system sets convergence coefficients for luminance and chrominance respectively. , ,in and For convergence strength, and These two coefficients represent the lower bound for convergence. They control the convergence in the sensitive region. Under these conditions, the degree to which luminance and chromaticity converge toward conservative values ​​is given in the embodiments.

[0055] To avoid overexposure caused by the overlapping of adjacent lights in the boundary area, the overlapping set is further defined as follows: ,in This is the overlap threshold. For the set... The allocation factor for the pixels within the range is written as:

[0056] in To be with the lamp Adjacent sets of lights, To avoid extremely small positive numbers with a denominator of zero, the brightness is adjusted accordingly. This means that overbrightness is suppressed through the combined effects of convergence and distribution. Color convergence is achieved linearly towards the achromatic axis, assuming... Neutral colors of the same brightness are ,but ,in To project onto this lamp, the color gamut is achievable. The operator, This is the chromaticity convergence coefficient, used to ensure that the result is physically achievable.

[0057] and After the calculation is complete, record it again as and This ensures that regardless of whether this step is enabled, subsequent HSV smoothing can work under a unified input format, maintaining the consistency of the method logic.

[0058] Step S106: This step does not depend on the enabling state of step S105, and always receives the target color of each lamp from the previous stage. and target brightness The system employs an HSV smoothing and limiting algorithm for temporal stabilization and issues control commands at a unified effective time to synchronize the lighting with the video. First, the colors are converted to HSV space to obtain the input hue and saturation of the current frame, denoted as... and Then convert the brightness to the device's brightness channel to obtain the input brightness. ,in The scaling factor for mapping linear brightness to device values ​​is given by calibration or the driver. First-order recursive smoothing is performed on the three channels, using the following formula: ,in represent or or , This is the smoothing result for this frame. This is the smoothed result of the previous frame. This is the input value for this frame. The smoothing coefficient. The result after smoothing. It is fed into the lighting formula generation module, where a unified group control formula is formed.

[0059] The group control recipes are distributed via multicast through multiple protocol interfaces, including a streaming interface based on DTLS / UDP, a gateway interface based on Zigbee, and an edge gateway interface based on Matter. Before multicasting, the system sets a uniform activation time for all lights and incorporates a clock reference during transmission. Alignment is complete. This ensures that multiple lights can switch synchronously on the same frame reference, maintaining strict consistency between the video image and ambient lighting. The unified activation time spans recipe generation, protocol transmission, and light execution; upon multicast arrival, it is executed simultaneously at the activation time. See [link to timing details] for the sequence relationship. Figure 3 , Figure 3 This is a time-series swimlane diagram for the present invention.

[0060] The present invention also provides an apparatus for performing the above-described method process. (See reference...) Figure 2 , Figure 2 This is a structural diagram of the platform module of the present invention. The device consists of a processing platform and multiple functional units, all operating on a unified clock reference. The system operates collaboratively in a pipeline manner. Input video is mirrored and fed into the processing flow while maintaining its original display quality. Redundant transcoding and caching are avoided throughout the entire process, thus meeting end-to-end latency constraints. To accommodate differences in step arrangement and optional switches across different embodiments, the device is designed with modularity and decoupling in mind. Each unit can operate independently or be partially enabled or bypassed as needed.

[0061] The correspondence between the steps and the device units is as follows: S101 corresponds to the HDMI receiving and pass-through unit, S102 corresponds to the video downsampling and preprocessing unit, S103 corresponds to the black border detection and active area cropping unit, S104 corresponds to the ROI mapping and color statistics unit and HDR color mapping unit, S105 corresponds to the sensitive area constraint and correction unit, and S106 corresponds to the lighting recipe generation and group control output unit.

[0062] The device is equipped with an HDMI receiver and pass-through unit. This unit handles EDID negotiation and clock alignment, passing the input video signal directly to the display while sending it into the processing flow from the other side. Both data streams share the same frame sequence. This unit retains the HDR metadata and color gamut identifier of the source material, providing an input benchmark consistent with the display for subsequent mapping.

[0063] The device includes a video downsampling and preprocessing unit. This unit performs anti-aliasing filtering and downsampling within a real-time budget, outputting the processed downsampled frame. This unit also performs RGB and HSV color representation conversion and linearization as needed, establishing a unified luminance scale. And spatial scales, providing input for subsequent statistics.

[0064] The device includes a black border detection and active area cropping unit. This unit identifies the positions of black borders and subtitles on the downsampled frame and generates a mask. The unit performs temporal smoothing on the mask and marks the main area and sensitive area, providing an effective color sampling range for subsequent ROI mapping and color statistics units.

[0065] The device is equipped with ROI mapping and color statistics units. These are used for mapping the main body region of downsampled frames. Above, combined with continuous mask Normalized Euclidean distance from pixel to lamp position The unit calculates the overall weight for each pixel. It then uses weighted aggregation to obtain the representative color and brightness of each light and provides the statistical results to the HDR color mapping unit.

[0066] The device is equipped with an HDR color mapping unit. This unit unifies the video to an approximately linear brightness based on the transfer curve. And determine the knee point based on the brightness distribution of the image. Sum of Indices The unit performs a non-linear mapping of brightness using a knee-point compression function to obtain the compressed target brightness, and then combines this with a representative color to generate the target color. When the target color exceeds the achievable color gamut of the luminaire, the unit uses the minimum color difference principle for projection correction to ensure that the output is physically achievable. Finally, the unit outputs the target color and target brightness for each luminaire, providing input for subsequent corrections and group control.

[0067] The device is equipped with a sensitive area constraint and correction unit. This unit is used to adjust the target color and brightness output by the ROI and HDR units, combined with the sensitive coverage ratio of black borders and subtitles. By setting the convergence coefficients of brightness and chromaticity and introducing a brightness distribution mechanism between adjacent lamps, it reduces color cast or local overbrightness caused by interference, thereby outputting a more stable and harmonious result. When not enabled, the input result remains unchanged and is passed to the next unit.

[0068] The device is equipped with a lighting recipe generation and group control output unit. After receiving the aforementioned results, this unit smooths and limits the target color and brightness to generate a unified lighting control recipe and sets a unified activation time for all luminaires. The generated recipe is distributed via multicast through various network interfaces, such as DTLS / UDP, Zigbee, or Matter, so that all luminaires switch synchronously under the same frame reference, thereby ensuring strict consistency between the video image and the ambient lighting.

[0069] In one optional embodiment, the scenario is a home esports scene, and the signal source is a game console or computer. The system operates under low latency conditions to ensure an immersive lighting experience under high-speed dynamic scenes. The sensitive area constraint and correction unit in step S105 is not enabled in this embodiment.

[0070] The system uses an HDMI receiver and pass-through unit to handle input access and capability negotiation. The input format is resolution. and frame rate This unit establishes a direct link, sending the input video to the display end as is, while simultaneously mirroring the same frame and splitting it to the analysis end. Both share a unified clock and frame order. The system reads the frame during a stable time slot of video synchronization and generates an effective time reference, denoted as [reference value]. The duration of a single frame is This duration is used as a benchmark for real-time budgeting.

[0071] In step S102, the system performs anti-aliasing filtering on the original frame in the video downsampling and preprocessing unit and scales it down proportionally, with a scaling ratio of [missing value]. The downsampled frame resolution is The system establishes a unified linear brightness scale based on the inverse transformation of the transfer curve, with pixel brightness denoted as... This process, while preserving the subject's outline and brightness levels, reduces the computational load per frame by two orders of magnitude, with an average measured time of [missing value]. The calculation does not span frames; in high-speed turning and running scenes, the downsampled frame preserves the brightness peak and edge gradient of the enemy character, thus providing a stable input for subsequent statistics. Subsequently, a unified brightness scale and spatial scale are established on this frame: the pixel code value is transformed by the inverse transformation of the transfer curve to obtain the linear color channel, and the linear color vector is denoted as... Under a unified color gamut, press Synthesized linear brightness, and , As a follow-up The brightness statistics input is the pixel integer coordinates. Normalization ,in , The value falls within ;No. The standardized installation position of the lamp is The normalized Euclidean distance from the pixel to the light is This is used for the ROI weight mapping function and color picker window in S104. This step outputs preprocessing parameters for direct use by S103–S106.

[0072] In step S103, the system generates a mask in the black border detection and active area clipping unit, and the mask is denoted as... When the average brightness of the upper and lower edge bands is less than And the proportion of continuous height is not less than The image is then identified as a black border and the mask is set to zero; the bottom height is taken as the image height. When the ratio of brightness and contrast of the band relative to the central reference area is not less than The system determines the text to be a subtitle and sets it to zero. The system then applies the mask. Spatial mean smoothing is used to reduce boundary spikes and isolated false positives. After smoothing, the mask value is no less than [value missing]. The set of pixels is defined as the main region, and the set is denoted as . This process eliminates interference from invalid areas, ensuring that subsequent statistics are based solely on the main image. In actual testing, in scenarios with chat pop-ups and bottom subtitles, the light color remained stable after elimination, without color shifting due to subtitle flickering.

[0073] In step S104, the system uses the normalized position of each lamp. Centered on the main area Create a color picker window; for pixels Composite weights ROI weight mapping function , , ,default Input is the steps. Provided linear colors and linear brightness Weighted statistics yielded a representative brightness of as well as To suppress highlight saturation and maintain tonal range, the knee point and exponent are taken as follows: and In this embodiment, Target brightness is .

[0074] The target color is constrained in terms of color gamut according to the principle of minimum color difference: in terms of brightness General Mapping to the device's achievable color gamut: if it's already within the achievable range, use it directly; if it's outside, while maintaining brightness and hue, only scale the chroma and project it to the achievable boundary to obtain... And guarantee color difference The output of this step is for each lamp. and and the effective time reference of step S101 Alignment, for use in steps S105 and S106.

[0075] In step S105, the sensitive region constraint and correction unit is not enabled in this embodiment. To maintain interface consistency, the output of step S104 is directly used as the input for the next step.

[0076] In step S106, the system will and Converted to HSV space and time-smoothed and clipped, updated as follows:

[0077]

[0078]

[0079]

[0080] in , , This refers to the unsmoothed hue, saturation, and device brightness; , , For smoothed hue, saturation, and device brightness; This is the time smoothing coefficient; a smaller value indicates a smoother response, and a larger value indicates a faster response. (Take a value of...) The relative change in single-frame clipping is no greater than The system is based on Unified distribution of group control recipes; single-lamp transmission latency of LAN DTLS and UDP is less than [specified value]. Zigbee's delay compensation after school hours is less than The single-lamp transmission latency of a Matter multicast cluster is less than When the number of light fixtures is not less than At that time, the group control switching rate is not less than The end-to-end latency of the entire link is no greater than Statistically, based on screen brightness increments as the trigger source, the light response time for explosion effects is no greater than [a certain value]. This ensures strict synchronization between lighting and visuals in high-speed dynamic scenes.

[0081] The effect achieved in this embodiment in a home e-sports scenario is as follows: Input S102 downsampling to Average calculation time No frame skipping; group control frame rate End-to-end delay Response time of lights during high-intensity events such as explosions Link latency satisfies , , Color difference between HDR knee compression and PQ curve ,exist Output under high light approximately Unsaturated color sampling; stable color picking after masking black borders and subtitles, resulting in high recognition accuracy. Subtitle interference reduction rate Sample size Quantity of lamps The system is stable during group control, and there is no perceptible disconnect between the visuals and lighting.

[0082] In another embodiment, the scene is a home theater, and the input is an HDR10 movie. Steps S101 to S104 are the same as in the previous embodiment, but are selected according to the brightness distribution of the movie. , Thus, in step S104, the target color of each lamp is obtained. and target brightness ,in Number the light fixture.

[0083] Now, step S105 is initiated, and the pixel overall weight is determined by the mask. ROI weight mapping function Multiplying them together, we get: These are the normalized coordinates of the pixels. For pixel index, The mask for step S103. Define the main body region. The sensitive coverage ratio within is:

[0084]

[0085] Based on this, convergence coefficients for luminance and chromaticity are given. , ,in , , , To coordinate the brightness of the boundary regions, an overlap set is defined. ,in Therefore, the allocation factor can be calculated as follows:

[0086] in, For the lamp The adjacency set, .

[0087] The corrected output for this step is: , ,in To and Colorless vectors of the same brightness For lamp The device can reach the color gamut, The chromaticity convergence coefficient is... In order to be in The projection operator on the surface maintains the brightness and hue unchanged, only scaling the chroma; and Based on the effective time benchmark Align and feed into step S106.

[0088] Under the same segment and time scale, comparing the lighting response with and without the viewing-friendly stabilization mechanism enabled, hue shift and brightness abrupt changes during prominent subtitle segments are suppressed, and the response during scene transitions is smoother. See [link to relevant documentation]. Figure 4 , Figure 4 A comparison of lighting response with the movie-friendly and stable viewing mechanism enabled and disabled. Based on real-world testing in a cinema setting, referencing a clip from *Dune*, the specific test results are as follows: Black border detection time... After enabling S105, the brightness retention error of the subtitle frame is maintained. Hue shift is effectively reduced; synchronization error of zoned color temperature control is improved. Compared to when S105 is not enabled, the standard deviation of chromaticity jitter decreases. This step incurs additional overhead. This does not violate end-to-end delay constraints.

[0089] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0090] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0091] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and inventive constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0092] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0093] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0094] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of HDMI video light synchronization that fuses black edge detection with HDR knee point compression, the method comprising: The application relates to a display system and a display method. The display system comprises: A display pass-through path and an analysis mirror path are formed after HDMI video is accessed, the two paths share the same frame sequence, and a unified frame time reference is obtained; A current frame of the mirror path is down-sampled and color linearized, a linear brightness scale is obtained according to a transfer curve of a film source, and a normalized space scale of pixels to lamps is established according to a lamp installation position; Black edges and subtitles are detected on the down-sampled frame, a mask with continuous values is generated, a main body area and a viewing sensitive area are demarcated according to the mask; A color sampling window is established in the main body area around each lamp, an ROI weight for pixel weighted statistics is generated, a comprehensive weight is obtained by combining the ROI weight and the mask, and representative colors and representative brightness are calculated; Knee point parameters and exponential parameters are determined according to brightness distribution of the main body area, target brightness is obtained by performing knee point compression, the target brightness is projected to a reachable color gamut of the lamps according to a minimum color difference principle under the premise of keeping the brightness and hue unchanged, and target colors are obtained; After the target colors and the target brightness are subjected to time smoothing processing and change rate limiting, group control formulas are generated according to a unified effective time and are sent to all lamps to realize synchronous switching of the same frame; 2. The method of claim 1, wherein, A viewing-friendly and stable mechanism can be selectively enabled in the display system, when the mechanism is turned on, the target brightness and the target colors are further subjected to limiting and smoothing processing to reduce flicker and color deviation, and when the mechanism is turned off, the limiting and smoothing processing is not performed to shorten the time delay.

3. The method of claim 1, wherein, The display pass-through path and the analysis mirror path read a shared frame sequence in a stable time slot of video synchronization, and the shared frame sequence serves as a unified frame time reference for subsequent processing steps.

4. The method of claim 1, wherein, The down-sampling is completed in the order of anti-aliasing processing and mean pooling, the color linearization is completed according to inverse transformation of an input transfer curve, and the linear brightness scale is consistent in representative quantity statistics and color mapping.

5. The method of claim 1, wherein, The black edge detection gives a judgment result based on the brightness mean value and the height proportion of the upper and lower edge bands, the subtitle detection gives a judgment result based on the brightness contrast and connectivity of the bottom band, and the threshold values of the two are determined by content adaptive rules; the mask forms a continuous value weight through local window averaging and directly participates in subsequent statistics.

6. The method of claim 1, wherein, The ROI weight is a monotonic decreasing function in the normalized space scale of pixels to lamps, and the decay speed is controlled by a single decay coefficient; the comprehensive weight is the product of the ROI weight and the mask weight.

7. The method of claim 1, wherein, The knee point parameters are determined according to the quantile points of the brightness distribution in the frame, the exponential parameters are determined according to the brightness dispersion degree; the color gamut constraint only scales the chroma under the premise of keeping the target brightness and the hue unchanged, and is projected to the boundary of the reachable color gamut of the lamps according to the minimum color difference principle. The time smoothing processing adopts first-order recursion and sets smoothing coefficients for three control channels respectively, and sets a single frame change rate limiting; the group control instruction contains a unified effective time and is aligned and compensated when sent, is sent through multicast or equivalent synchronization mode, and makes all lamps synchronously switch under the same frame time reference.

8. The method of claim 1, wherein, The system introduces a sensitive coverage ratio in the viewing-friendly stabilization mechanism to quantify the degree of color sampling window interference by subtitles or black bars; and performs convergence correction on the target brightness and target color according to the sensitive coverage ratio, and performs brightness redistribution in the adjacent lamp border area, to suppress local mutations caused by subtitle strips or edge high contrast, thereby improving the consistency and stability of the picture and the light.

9. The method of claim 8, wherein, The convergence correction sets convergence intensity for the target brightness and the target color respectively, and adaptively adjusts the correction amplitude according to the sensitive coverage ratio, to realize smooth transition and visual stability.

10. A video lighting synchronization apparatus that fuses black edge detection with HDR knee point compression, characterized by, The system comprises: An HDMI receiving and passing unit for completing capability negotiation with a display end, establishing a display passing path and an analysis mirroring path, and providing a shared frame sequence as a frame time reference; A video downsampling and preprocessing unit for downsampling and color linearization on the frame in the analysis mirroring path, outputting a linear brightness scale and a normalized spatial scale of pixels to lamps; A black bar detection and active area cropping unit for detecting black bars and subtitles on the downsampled frame and outputting a mask for shielding or weighting; An ROI mapping and color statistics unit for establishing a color sampling window around each lamp, generating a distance-decreasing ROI weight according to the normalized spatial scale, and synthesizing a comprehensive weight with the mask to calculate the representative brightness and representative color of the lamp; An HDR color mapping unit for setting a tone mapping function containing at least one knee point according to the brightness distribution in the frame, compressing the representative brightness at the knee point, and constraining the representative color to the reachable color gamut and brightness range of the lamp, outputting the target brightness and target color; A sensitive area constraint and correction unit for applying convergence constraints on the target brightness and target color according to the coverage ratio of the viewing-sensitive area in the color sampling window, and performing brightness redistribution in the adjacent lamp border area to suppress local mutations caused by subtitle strips and edge high contrast; A light recipe generation and group control output unit for performing time smoothing processing on the target brightness and target color and setting a change rate constraint, generating group control instructions containing a unified effective time and issuing them to all lamps to realize synchronous switching.

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