Color correction methods, devices and storage media for virtual photography

Abstract

This disclosure relates to a color correction method, apparatus, and storage medium for virtual photography. The method includes: performing color correction on a target image to be displayed on a screen according to a color mapping table, wherein the color mapping table represents the mapping relationship between the input color of the screen and the target color to be displayed on the screen, and the target color is a color that can be obtained by using a color acquisition device to acquire the color of the image to be displayed on the screen, replacing the image acquisition device; and displaying the color-corrected target image on the screen to perform the virtual photography. This allows for the acquisition of a photographic image that harmonizes the virtual and real scenes.

Description

Technical Field

[0001] This disclosure relates to the field of virtual photography technology, and in particular to a color correction method, apparatus and storage medium for virtual photography. Background Technology

[0002] With the continuous advancement of display and control technologies, virtual shooting is increasingly being used in film and television production, and the requirements for the rendering capabilities of virtual screens are also constantly increasing, with color accuracy being one of them.

[0003] If the screen's color deviation is significant, it will cause color discrepancies in the captured footage, requiring dedicated color correction during the virtual shooting phase in post-production, which is time-consuming and labor-intensive. Related technologies can employ specialized processing modules for color correction to eliminate screen color deviations. For example, Figure 1 and Figure 2 These are the images taken before and after color correction, respectively. Apart from the human figures, the rest of the images are virtual screen scenes.

[0004] However, the color correction methods in related technologies may have the problem of inconsistency between the virtual scene and the real scene displayed on the screen. Summary of the Invention

[0005] In view of this, this disclosure proposes a color correction method, device and storage medium for virtual shooting, thereby enabling the acquisition of shooting images that coordinate virtual and real scenes.

[0006] According to a first aspect of this disclosure, a color correction method for virtual shooting is provided, comprising: performing color correction on a target image to be displayed on a screen according to a color mapping table, wherein the color mapping table represents a mapping relationship between an input color of the screen and a target color to be displayed on the screen, and the target color is a color that can be obtained by performing color acquisition on the image to be displayed on the screen via a color acquisition device instead of an image acquisition device; and displaying the color-corrected target image on the screen to perform the virtual shooting.

[0007] In one possible implementation, color correction of the target image to be displayed on the screen according to the color map table includes: determining the target color to be displayed on the screen; solving for the target input color according to the color map table and the target color; and adjusting the color of the target image to the target input color.

[0008] In one possible implementation, before color correction is performed on the target image to be displayed on the screen according to the color map table, the color correction method further includes: generating color sampling points using a standard color generator as input color sampling values; rendering the color sampling points on the screen, and using the color acquisition device to acquire the color obtained after the color conversion of the color sampling points through the screen as color acquisition values; analyzing the input color sampling values ​​and the color acquisition values ​​to construct the color map table for representing the mapping relationship between the input color sampling values ​​and the color acquisition values, wherein the mapping relationship between the input color sampling values ​​and the color acquisition values ​​corresponds to the mapping relationship between the input color and the target color.

[0009] In one possible implementation, using a standard color generator to generate color sampling points as input color sampling values ​​includes: obtaining the arrangement of color sampling points corresponding to the target image; and causing the standard color generator to generate corresponding color sampling points according to the arrangement.

[0010] In one possible implementation, the arrangement is related to the accuracy and time required for the color correction.

[0011] In one possible implementation, the color sampling points are rendered on the screen, and the color obtained after color conversion of the color sampling points through the screen is collected by the color acquisition device as a color acquisition value. This includes: rendering the color sampling points on the screen such that the color corresponding to each color sampling point is displayed on the screen for a preset time period; collecting the color displayed on the screen at a preset acquisition frequency using the color acquisition device to obtain color acquisition values ​​and acquisition times, wherein each preset time period corresponds to multiple color acquisition values ​​within the preset time period; and analyzing the input color sampling values ​​and the color acquisition values ​​to construct a color mapping table representing the mapping relationship between the input color sampling values ​​and the color acquisition values. This includes: for each preset time period, taking a preset number or more color acquisition values ​​from the multiple color acquisition values ​​within the preset time period as the color acquisition value corresponding to the color sampling point of that preset time period, thereby constructing the color mapping table representing the mapping relationship between the input color sampling values ​​and the color acquisition values.

[0012] In one possible implementation, displaying a color-corrected target image on the screen for virtual shooting includes: using the image acquisition device to capture images of the color-corrected target image displayed on the screen and the real-world scene in front of the screen to obtain a captured image, wherein in the captured image, the color of the virtual object in the color-corrected target image matches the color of the physical object in the real-world scene, and the type of the virtual object is the same as the type of the physical object.

[0013] According to a second aspect of this disclosure, a color correction device for virtual shooting is provided, comprising: a color correction module for color correction of a target image to be displayed on a screen according to a color mapping table, wherein the color mapping table represents a mapping relationship between an input color of the screen and a target color to be displayed on the screen, and the target color is a color that can be obtained by color acquisition of the image to be displayed on the screen via a color acquisition device instead of an image acquisition device; and a display module for displaying the color-corrected target image on the screen for performing the virtual shooting.

[0014] In one possible implementation, the color correction module is configured to: determine the target color to be displayed on the screen; solve for the target input color based on the color map and the target color; and adjust the color of the target image to the target input color.

[0015] In one possible implementation, the color correction device further includes: a construction module for constructing the color mapping table, wherein the construction module is configured to: generate color sampling points using a standard color generator as input color sampling values; render the color sampling points on the screen and use the color acquisition device to acquire the color obtained by color conversion of the color sampling points through the screen as color acquisition values; analyze the input color sampling values ​​and the color acquisition values ​​to construct the color mapping table for representing the mapping relationship between the input color sampling values ​​and the color acquisition values, wherein the mapping relationship between the input color sampling values ​​and the color acquisition values ​​corresponds to the mapping relationship between the input color and the target color.

[0016] In one possible implementation, the building module is configured to: obtain the arrangement of color sampling points corresponding to the target image; and cause the standard color generator to generate the corresponding color sampling points according to the arrangement.

[0017] In one possible implementation, the arrangement is related to the accuracy and time required for the color correction.

[0018] In one possible implementation, the building module is configured to: render the color sampling points on the screen, such that the color corresponding to each color sampling point is displayed on the screen for a preset time period; use the color acquisition device to acquire the colors displayed on the screen at a preset acquisition frequency to obtain color acquisition values ​​and acquisition times, wherein each preset time period corresponds to multiple color acquisition values ​​acquired within the preset time period; for each preset time period, select a preset number or more color acquisition values ​​acquired within the preset time period as the color acquisition values ​​corresponding to the color sampling points of that preset time period, thereby constructing a color mapping table to represent the mapping relationship between the input color sampling values ​​and the color acquisition values.

[0019] In one possible implementation, the display module is configured to: use the image acquisition device to capture images of the color-corrected target image displayed on the screen and the real-world scene in front of the screen to obtain a captured image, wherein, in the captured image, the color of the virtual object in the color-corrected target image matches the color of the entity object in the real-world scene, and the type of the virtual object is the same as the type of the entity object.

[0020] According to a third aspect of this disclosure, a color correction apparatus for virtual shooting is provided, comprising: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to implement the above-described color correction method when executing the instructions stored in the memory.

[0021] According to a fourth aspect of this disclosure, a non-volatile computer-readable storage medium is provided, on which computer program instructions are stored, wherein the computer program instructions, when executed by a processor, implement the above-described color correction method.

[0022] According to the color correction method, apparatus, and storage medium for virtual shooting disclosed herein, before rendering the target image on the screen, the target image is first color-corrected using a color mapping table independent of the image acquisition device. Then, the color-corrected target image is displayed on the screen to obtain the captured image of virtual shooting. Thus, in the scenario of combined virtual and real shooting, the color correction problem is defined as a screen color correction problem, which is independent of the camera. After constructing the color mapping table, the camera-independent color mapping table is applied during the shooting stage to change the image on the screen. The image on the screen is then rendered after being corrected by the color mapping table, so that the optical response is the same as the original image on the screen. This results in a unified color style between the virtual and real scenes, and a shooting image in which the colors of the virtual and real scenes are coordinated.

[0023] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0024] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.

[0025] Figure 1 This shows the image displayed on the screen without color correction.

[0026] Figure 2 This shows the screen display after color correction.

[0027] Figure 3 A flowchart illustrating a color correction method for virtual shooting according to an exemplary embodiment of the present disclosure is shown.

[0028] Figure 4 A system architecture diagram of a color correction method for virtual shooting according to an exemplary embodiment of the present disclosure is shown.

[0029] Figure 5 A block diagram of a color correction apparatus for virtual shooting according to an exemplary embodiment of the present disclosure is shown.

[0030] Figure 6 A schematic diagram of the structure of an electronic device according to an embodiment of the present disclosure is shown. Detailed Implementation

[0031] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0032] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0033] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0034] Virtual shooting, also known as digital background shooting, involves projecting video or real-time rendered images onto a screen, such as an LED screen, as a digital background for film and television shooting. Digital background shooting offers significant technological advantages over traditional green screen chroma keying. By projecting real-time rendered 3D scenes onto a screen, digital background shooting allows actors to be placed within a virtual environment, enabling the shooting of exterior scenes or science fiction backdrops within a studio.

[0035] When conducting virtual shooting, the image displayed on the screen (also known as the upper screen image) needs to be aligned with the real scene in front (also known as the foreground). The virtual image is used as the background, and the image displayed on the screen and the foreground are blended and matched to achieve a harmonious image. The camera is then used to capture the blended and matched image, thereby realizing virtual shooting.

[0036] For example, in a studio, a small patch of grass, such as a few square meters, can be set up in the foreground. The grass from the nearby real set can be used as the foreground, while a very large patch of grass in the distance (not a real set) can be used as the background. The background image can be rendered on the screen, and the rendered image can be used as the background. By using an image acquisition device, such as a camera, to photograph the grass from the real set and the rendered image, a very large grass field can be captured. In this way, only a few square meters of grass need to be laid out, and the rest can be filled in with the image on the screen, so that a football field with a very large grass field can be captured.

[0037] However, even if the grass on the actual set and the grass displayed on the screen look the same, there are some color errors on the screen. This will cause the colors displayed on the screen (the colors after being changed by the screen's color system) to be different from the colors of the actual set, resulting in a color inconsistency between the grass on the actual set and the grass displayed on the screen.

[0038] Therefore, the present invention discloses a color correction method, apparatus and system for virtual shooting, so as to make the colors of the virtual scene presented on the screen consistent with the colors of the real scene.

[0039] The following combination Figures 3-6 This invention will elaborate on the color correction method and apparatus for virtual shooting according to exemplary embodiments of the present disclosure.

[0040] Figure 3 A flowchart illustrating a color correction method for virtual photography according to an exemplary embodiment of the present disclosure is shown. Figure 3 As shown, the color correction method includes:

[0041] Step S320: Perform color correction on the target image to be displayed on the screen according to the color mapping table. The color mapping table represents the mapping relationship between the input color of the screen and the target color to be displayed on the screen. The target color is the color that can be obtained by color acquisition device to acquire the color of the image to be displayed on the screen instead of image acquisition device.

[0042] In this embodiment, the target screen is the screen to be displayed, which is also called the on-screen screen. Therefore, the target screen is actually the target on-screen screen.

[0043] Research has revealed that the process of capturing the corresponding colors in the screen image using a real camera, generating a color map based on the captured colors, and then correcting the colors of the screen image according to this color map essentially involves using a real camera for final acquisition. This is equivalent to measuring the colors of the screen and camera color systems as a whole color system. The color map generated based on the measured values ​​is the inverse mapping of the colors of this whole color system. However, the camera's color process is a multi-parameter defined, styled imaging process. Using this color map will cause the camera style of the virtual scene in the virtual shooting to be canceled out by the color map, while the real scene will retain the camera style, resulting in a discrepancy between the final virtual scene and the real scene.

[0044] In other words, even after color correction of the image to be displayed on the screen based on color mapping related to the colors that the camera can obtain by capturing colors from the image to be displayed on the screen, the problem of inconsistency between the virtual and real scenes still exists.

[0045] In this embodiment, the color correction used for the image to be displayed on the screen is a color mapping table related to the colors that can be obtained by a color acquisition device (rather than an image acquisition device (such as a camera)) from the image to be displayed on the screen. Therefore, the color correction problem is simplified to a simple screen color correction problem and is independent of the camera. Since this color mapping table is only related to the screen's color system and not to the color system of the image acquisition device, therefore, as... Figure 4 As shown, during the shooting stage, before rendering the target image (the image on the screen) on the screen (the virtual shooting screen), the target image is first color-corrected using a color mapping table (via a color correction system) so that the input color of the screen is corrected to the input color required for the screen to truly display the target image.

[0046] In one possible implementation, the color map table includes a three-dimensional lookup table. For example, this three-dimensional lookup table is an RGB color lookup table.

[0047] Step S340: Display the color-corrected target image on the screen for virtual shooting.

[0048] In this embodiment, as Figure 4 As shown, after color correction of the upper screen image, the corrected upper screen image is input to the screen (virtual screen capture). For example, the color-corrected target image data can be transmitted to a rendering device, which then renders the target image onto the screen, displaying the color-corrected target image. During virtual shooting, the rendered image and the real-world image (real scene) can be captured by an image acquisition device (e.g., a camera), thus obtaining a combined virtual and real-world shooting image.

[0049] Because the target image has been color-corrected according to the color map table before the screen renders it, the input color of the screen is corrected to the input color required for the screen to truly display the target image. Therefore, the screen can display the target image using the corrected input color, thus obtaining a shooting image that is coordinated between the virtual and real scenes.

[0050] According to the color correction method for virtual shooting in this embodiment, before rendering the target image on the screen, the target image is first color-corrected using a color mapping table independent of the image acquisition device. Then, the color-corrected target image is displayed on the screen to obtain the shooting image of virtual shooting. Thus, the color correction problem in the combined virtual and real shooting scenario is defined as a screen color correction problem, which is independent of the camera. After constructing the color mapping table, the camera-independent color mapping table is applied during the shooting stage to change the image on the screen. The image on the screen is then rendered after being corrected by the color mapping table, so that the same optical response as the original image on the screen can be obtained. This results in a unified image style between virtual and real colors, and the screen display can truly achieve what you see is what you need.

[0051] In one possible implementation, step S320 may include: determining a target color to be displayed on the screen; solving for a target input color based on the color mapping table and the target color; and adjusting the color of the target image to the target input color.

[0052] In this embodiment, since the mapping relationship between the input color of the screen and the target color to be displayed on the screen can be determined according to the color mapping table, and the screen's color system will change the color of the target image, in order for the screen to finally display the target image, it is necessary to solve for the corresponding input color according to the color mapping table and the target color as the target input color. The screen can display the target image by using the input color.

[0053] After determining the input color, the color of the target image can be adjusted to the target input color. In this way, the input color of the screen is adjusted to the target input color, and the final image displayed on the screen is actually the target image. This allows for the same optical response as the original target image, thus enabling the shooting of images that are coordinated with the virtual scene and the real scene.

[0054] In one possible implementation, a color mapping table can be pre-constructed. This can be achieved by: generating color sampling points using a standard color generator as input color sampling values; rendering the color sampling points on the screen and using the color acquisition device to acquire the colors obtained after color conversion of the color sampling points through the screen as color acquisition values; analyzing the input color sampling values ​​and the color acquisition values ​​to construct the color mapping table representing the mapping relationship between the input color sampling values ​​and the color acquisition values, wherein the mapping relationship between the input color sampling values ​​and the color acquisition values ​​corresponds to the mapping relationship between the input color and the target color.

[0055] In this embodiment, as Figure 4 As shown, during the screen calibration phase, a standard color generator is used to generate various color sampling points of the standard sample color to obtain the input color sample value `color_sample_set`, thus ensuring that the input color conforms to the standard definition and is unique. The standard color generator can be implemented by software to generate the required color values ​​according to predetermined rules. These color sampling points are then rendered on a virtual screen via the screen display interface. The rendered color is the color obtained after color conversion of each color sampling point on the screen. Simultaneously, the input color sample value `color_sample_set` is sent to the color analysis system.

[0056] Then, as Figure 4 As shown, during the screen calibration phase, instead of using a camera to collect colors from the screen, a professional color acquisition device (standard color collector), such as a color analyzer, is used to capture the rendered image to obtain color measurement values ​​(color_measure_set). These color measurement values ​​(color_measure_set) are then sent to the color analysis system. Next, the color analysis system performs statistical analysis on the color sample values ​​(color_sample_set) and the color measurement values ​​(color_measure_set), and can construct a function representing the mapping relationship between these two values, known as a color mapping table (Map_Func).

[0057] In other words, during the screen calibration phase, based on changes in screen brightness, darkness, reddening, greendening, etc., and by leveraging the relationship between the color sample value `color_sample_set` and the color measurement value `color_measure_set`, dense sampling at multiple points can be performed. This should enable the construction of a color mapping relationship (i.e., a color mapping table) between the color sample value `color_sample_set` and the color measurement value `color_measure_set`. After constructing this color mapping relationship, it's possible to specify which colors should be input to the screen when certain colors need to be displayed, i.e., the colors to which the displayed image should be adjusted.

[0058] For example, the color sample value color_sample_set and the color measurement value color_measure_set are compared. If the color measurement value color_measure_set is greater than the color sample value color_sample_set, a color mapping table Map_Func is constructed to reduce the color sample value color_sample_set; if the color measurement value color_measure_set is less than the color sample value color_sample_set, a color mapping table Map_Func is constructed to increase the color sample value color_sample_set.

[0059] The color map table Map_Func satisfies color_sample_set = H_screen(Map_Func(color_sample_set)), where H_screen() represents the inverse function of the color map table Map_Func. In this way, the target image corresponding to color_sample_set can be counteracted by the dual effects of the color map table Map_Func and its inverse function, thus negating the color changes of the screen's color system on the image displayed on the screen.

[0060] Standard color pickers are generally manual, but manufacturers provide a software development kit (SDK) for the standard color picker. The SDK can be used to develop programs for automatically building color maps, thus enabling the automatic construction of color maps through program control.

[0061] To achieve synchronization between screen color switching and standard color sampling, a computer process is used to control the display of multiple color sampling points generated by the standard color generator and the acquisition by the standard color collector. After these multiple color sampling points are rendered on the screen, the standard color collector is controlled to acquire the color sampling points displayed on the screen to obtain color acquisition values. Then, the aforementioned display and acquisition are performed in a loop and repeated. After the display and acquisition are completed, a color mapping table is constructed based on the color sampling points and color acquisition values.

[0062] For example, a program developed using the SDK sets 1000 color sampling points for the screen. It sequentially processes these color sampling points, processing them sequentially: one color sampling point is processed, then the next is processed, and so on, until all color sampling points are processed, resulting in the screen color `colors_in` and the sampled color `colors_out`. Both satisfy `colors_out = H(colors_in)`, where H() is a function of the screen's color system. Then, the program calculates a color mapping table `color_mapping` based on the screen color `colors_in` and the sampled color `colors_out`, ensuring that `colors_in = H(color_mapping(colors_in))`. This uses the color mapping table to correct the screen color, negating the function of the screen's color system and ensuring that the entire color display process matches the input.

[0063] Combination Figure 4 As can be understood, this embodiment first uses a color mapping table (Map_Func) to perform color correction on the upper screen image. Thus, the input to the virtual capture screen is Map_Func(color_sample_set). After Map_Func(color_sample_set) is rendered by the screen, it becomes H_screen(Map_Func(color_sample_set)). This cancels out the color changes of the screen's color system on the upper screen image, thereby achieving the same optical response as the original upper screen image. The real scene and the virtual scene (upper screen image) in the captured image are coordinated. Therefore, the virtual capture screen can be controlled so that it displays the desired color, truly achieving "what you see is what you need."

[0064] According to this embodiment, during the screen calibration stage, a standard color generator is used as input (color_sample_set), and a standard color acquisition device is used to measure the output (color_measure_set), ensuring the accuracy of the calculated color mapping table. The screen is sampled using a standard color acquisition device, and only the screen color process is modeled to determine the color mapping table. During the shooting stage, the target image to be displayed on the screen is color-corrected according to this color mapping table, and the captured image is obtained using the color-corrected target image. In this way, the colors of the background and the real scene in the captured image are consistent.

[0065] Furthermore, since the color correction process in this embodiment is independent of the real camera, this embodiment can simplify the color correction process. This is because the virtual shooting scene usually has multiple screens and multiple cameras, such as N screens and M cameras. The color correction process is related to both M cameras and N screens, so it requires M times of processing to build the color map table. In contrast, if the color correction process is independent of the camera, decoupling the entire color correction process from the camera's color system, then only N times of processing to build the color map table are needed, reducing the dimensionality of the color map table construction process.

[0066] In one possible implementation, using a standard color generator to generate color sampling points as input color sampling values ​​includes: obtaining the arrangement of color sampling points corresponding to the target image; and causing the standard color generator to generate corresponding color sampling points according to the arrangement.

[0067] In this embodiment, the arrangement of color sampling points may include, but is not limited to, the number and / or distribution location of color sampling points (i.e., the position of color sampling points in the image). The arrangement of color sampling points can be preset according to the type of the image displayed on the screen and / or the scene sampling colors. For example, if the image displayed on the screen of a virtual scene is a grassy area at a certain location, then multiple green sampling points that can cover the grassy area can be arranged at that location.

[0068] It can also display color regions corresponding to multiple color sampling points of different colors at different locations on the same screen, so as to obtain the color sampling values ​​corresponding to multiple color sampling points at the same time, thereby improving the efficiency of color mapping table establishment.

[0069] This allows for more precise screen calibration.

[0070] In one possible implementation, the arrangement is related to the accuracy and time required for the color correction.

[0071] In this embodiment, the denser the color sampling points are arranged (and the smaller the color difference between the sampling points), the higher the accuracy of the color map table constructed using dense color sampling points, and correspondingly, the higher the accuracy of color correction. Conversely, the sparser the color sampling points are arranged, the lower the accuracy of the color map table constructed using sparse color sampling points, and correspondingly, the lower the accuracy of color correction. Furthermore, the denser the color sampling points are arranged, the more time is required to construct the color map table based on the dense color sampling points; conversely, the sparser the color sampling points are arranged, the less time is required to construct the color map table based on the sparse color sampling points. Therefore, when constructing the color map table, the arrangement of the color sampling points can be determined according to the required accuracy and / or time for color correction.

[0072] Therefore, it is possible to reduce calibration time while ensuring a certain level of calibration accuracy.

[0073] In one possible implementation, the color sampling points are rendered on the screen, and the color obtained after the color sampling points have undergone color conversion on the screen is collected by the color acquisition device as a color acquisition value. This includes: rendering the color sampling points on the screen such that the color corresponding to each color sampling point is displayed on the screen for a preset time period; and collecting the colors displayed on the screen using the color acquisition device at a preset collection frequency to obtain color acquisition values ​​and collection times, wherein each preset time period corresponds to multiple color acquisition values ​​collected within the preset time period.

[0074] Analyzing the input color sampling value and the color acquisition value to construct a color mapping table representing the mapping relationship between the input color sampling value and the color acquisition value includes: for each preset time period, taking a preset number or more color acquisition values ​​from multiple color acquisition values ​​acquired within the preset time period as the color acquisition values ​​corresponding to the color sampling point of the preset time period, so as to construct the color mapping table representing the mapping relationship between the input color sampling value and the color acquisition value.

[0075] For example, a preset time period can be set to 1 second, meaning each color sample value is displayed on the screen for one second. The color sampling device is operated to sample the colors displayed on the screen at a sampling frequency of 20 times per second. Theoretically, 20 identical color sample values ​​can be obtained per second. However, due to the delays in the generation of color sampling points, the rendering to the screen, and the data acquisition and transmission process by the color sampling device, and the possible discrepancies between the time when the color starts to appear on the screen and the time when the color sampling device starts to collect data, the color sample values ​​may contain some noise. For example, more than two color sample values ​​may appear within a preset time period. The sampling frequency of the color acquisition device can be set high enough relative to the preset time period to obtain a sufficient number of color acquisition values. In this way, except for the noise that may exist at the edge of the preset time period, most of the color acquisition values ​​can correspond to the colors displayed on the screen. Therefore, for each preset time period, a preset number (e.g., 15) or more of the color acquisition values ​​collected within the preset time period can be used as the color acquisition values ​​corresponding to the color sampling points of that preset time period. For example, if there are 16 A values ​​and 4 B values ​​among 20 color sampling values ​​corresponding to the same preset time period, then the color sampling value is taken as A. This avoids the impact of noise caused by time misalignment on the establishment of the color mapping table.

[0076] In one possible implementation, the target color to be displayed on the screen is the target color of a virtual object, which is determined by the color of a physical object in front of the screen during virtual shooting, and the type of the virtual object is the same as the type of the physical object; wherein, in the captured image of the virtual shooting, the color of the virtual object in the color-corrected target image matches the color of the physical object in front of the screen.

[0077] For example, a small patch of grass, say a few square meters, can be set up in the studio. This real grass (the physical object) is used as the foreground, and its color is assumed to be C. A much larger patch of grass (a virtual object) in the distance (not part of the real set) is used as the upper screen image. To ensure a smooth transition between the grass on the screen and the real grass in the final shot, the "target color to be displayed on the screen" in step S320 can be set to color C. Using a mapping relationship, the input color (i.e., the corrected color) is determined, and rendering is performed on the screen based on this input color. Thus, the color of the upper screen image is color E, which should be consistent with or substantially consistent with color C. This ensures that the colors of the real grass and the grass displayed on the screen are harmonious and the transition is smooth. Actors performing on real grass can create the effect of a very large lawn.

[0078] The term "matching" here is not limited to being identical. For example, a color that is slightly lighter or darker than color C can be set as the "target color" as needed, so that virtual objects on the screen and physical objects can present the desired effects such as perspective and lighting.

[0079] Figure 5 A block diagram of a color correction apparatus for virtual photography according to an exemplary embodiment of the present disclosure is shown. Figure 5 As shown, the color correction device 500 may include a color correction module 510 and a display module 520.

[0080] The color correction module 510 is used to perform color correction on the target image to be displayed on the screen according to a color mapping table. The color mapping table represents the mapping relationship between the input color of the screen and the target color to be displayed on the screen. The target color is a color that can be obtained by using a color acquisition device to acquire the color of the image to be displayed on the screen, replacing the image acquisition device. The display module 520 is connected to the color correction module 510 and is used to display the color-corrected target image on the screen for the virtual shooting.

[0081] In one possible implementation, the color correction module 510 is configured to: determine the target color to be displayed on the screen; solve for the target input color based on the color map and the target color; and adjust the color of the target image to the target input color.

[0082] In one possible implementation, the color correction device 500 may further include: a construction module (not shown) for constructing the color mapping table, wherein the construction module is configured to: generate color sampling points using a standard color generator as input color sampling values; render the color sampling points on the screen and use the color acquisition device to acquire the color obtained by color conversion of the color sampling points through the screen as color acquisition values; analyze the input color sampling values ​​and the color acquisition values ​​to construct the color mapping table for representing the mapping relationship between the input color sampling values ​​and the color acquisition values, wherein the mapping relationship between the input color sampling values ​​and the color acquisition values ​​corresponds to the mapping relationship between the input color and the target color.

[0083] In one possible implementation, the building module is configured to: obtain the arrangement of color sampling points corresponding to the target image; and cause the standard color generator to generate the corresponding color sampling points according to the arrangement.

[0084] In one possible implementation, the arrangement is related to the accuracy and time required for the color correction.

[0085] In one possible implementation, the building module is configured to: render the color sampling points on the screen, such that the color corresponding to each color sampling point is displayed on the screen for a preset time period; use the color acquisition device to acquire the colors displayed on the screen at a preset acquisition frequency to obtain color acquisition values ​​and acquisition times, wherein each preset time period corresponds to multiple color acquisition values ​​acquired within the preset time period; for each preset time period, select a preset number or more color acquisition values ​​acquired within the preset time period as the color acquisition values ​​corresponding to the color sampling points of that preset time period, thereby constructing a color mapping table to represent the mapping relationship between the input color sampling values ​​and the color acquisition values.

[0086] In one possible implementation, the display module 520 is configured to: use the image acquisition device to capture images of the color-corrected target image displayed on the screen and the real scene image in front of the screen to obtain a captured image, wherein, in the captured image, the color of the virtual object in the color-corrected target image matches the color of the entity object in the real scene image, and the type of the virtual object is the same as the type of the entity object.

[0087] In some embodiments, the functions or modules of the apparatus provided in this disclosure can be used to perform the methods described in the above method embodiments. The specific implementation can be referred to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0088] This disclosure also proposes a computer-readable storage medium storing computer program instructions that, when executed by a processor, implement the above-described method. The computer-readable storage medium can be volatile or non-volatile.

[0089] This disclosure also proposes an electronic device, including: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to implement the above-described color correction method when executing the instructions stored in the memory.

[0090] Figure 6 A schematic diagram of the structure of an electronic device according to an embodiment of the present disclosure is shown below. Figure 6 The electronic device 60 may include a processor 61 and a memory 62. Exemplarily, the processor 61 and the memory 62 are interconnected via a bus 63. The memory 62 stores computer-executable instructions; the processor 61 executes the computer-executable instructions stored in the memory 62, causing the processor 61 to perform the color correction method as shown in the above method embodiment.

[0091] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A color correction method for virtual shooting, characterized in that, include: A standard color generator is used to generate color sampling points as input color sampling values; The color sampling points are rendered on the screen, and the color obtained after the color sampling points are converted by the screen is collected by a color acquisition device as the color acquisition value. The input color sample values ​​and the color acquisition values ​​are analyzed to construct a color mapping table that represents the mapping relationship between the input color sample values ​​and the color acquisition values. The color mapping table is independent of the image acquisition device. The target image to be displayed on the screen is color-corrected according to the color mapping table, wherein the color mapping table represents the mapping relationship between the input color of the screen and the target color to be displayed on the screen, and the target color is the color that can be obtained by the color acquisition device to acquire the color of the image to be displayed on the screen instead of the image acquisition device. The mapping relationship between the input color sampling value and the color acquisition value corresponds to the mapping relationship between the input color and the target color. The color-corrected target image is displayed on the screen for the virtual shooting. The use of a standard color generator to generate color sampling points as input color sampling values ​​includes: Obtain the arrangement of color sampling points corresponding to the target image; The standard color generator is arranged in the described manner to generate the corresponding color sampling points. The arrangement method is related to the accuracy and time required for the color correction. The target color to be displayed on the screen is the target color of the virtual object, which is determined by the color of the physical object in front of the screen during virtual shooting.

2. The color correction method according to claim 1, characterized in that, Color correction of the target image to be displayed on the screen according to the color mapping table includes: Determine the target color to be displayed on the screen; The target input color is determined based on the color mapping table and the target color. Adjust the color of the target image to the target input color.

3. The color correction method according to claim 1, characterized in that, The color sampling points are rendered on the screen, and the color obtained after color conversion of the color sampling points through the screen is acquired using the color acquisition device as the color acquisition value, including: The color sampling points are rendered on the screen so that the color corresponding to each color sampling point is displayed on the screen for a preset time period; The color acquisition device is used to acquire the colors displayed on the screen at a preset acquisition frequency to obtain color acquisition values ​​and acquisition time. Each preset time period corresponds to multiple color acquisition values ​​acquired within the preset time period. Analyzing the input color sample values ​​and the color acquisition values ​​to construct a color mapping table representing the mapping relationship between the input color sample values ​​and the color acquisition values ​​includes: For each preset time period, a preset number or more of the color sampling values ​​collected within the preset time period are used as the color sampling values ​​corresponding to the color sampling point of that preset time period, so as to construct the color mapping table for representing the mapping relationship between the input color sampling values ​​and the color sampling values.

4. The color correction method according to claim 1, characterized in that, The type of the virtual object is the same as the type of the entity object; In the virtual shooting scene, the color of the virtual object in the color-corrected target image matches the color of the physical object in front of the screen.

5. A color correction device for virtual shooting, characterized in that, include: A construction module is configured to: generate color sampling points using a standard color generator as input color sampling values; render the color sampling points on the screen and acquire the colors obtained after color conversion of the color sampling points through the screen using a color acquisition device as color acquisition values; analyze the input color sampling values ​​and the color acquisition values ​​to construct a color mapping table representing the mapping relationship between the input color sampling values ​​and the color acquisition values, wherein the color mapping table is independent of the image acquisition device; The color correction module is used to perform color correction on the target image to be displayed on the screen according to the color mapping table. The color mapping table represents the mapping relationship between the input color of the screen and the target color to be displayed on the screen. The target color is the color that can be obtained by the color acquisition device to acquire the color of the image to be displayed on the screen instead of the image acquisition device. The mapping relationship between the input color sampling value and the color acquisition value corresponds to the mapping relationship between the input color and the target color. A display module is used to display the color-corrected target image on the screen for the purpose of virtual shooting. The construction module is configured to: acquire the arrangement of color sampling points corresponding to the target image; and cause the standard color generator to generate corresponding color sampling points according to the arrangement, wherein the arrangement is related to the accuracy and time required for color correction. The target color to be displayed on the screen is the target color of the virtual object, which is determined by the color of the physical object in front of the screen during virtual shooting.

6. A color correction device for virtual shooting, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor is configured to implement the color correction method according to any one of claims 1 to 4 when executing instructions stored in the memory.

7. A non-volatile computer-readable storage medium storing computer program instructions thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the color correction method according to any one of claims 1 to 4.

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