CN115115743A - Method for filling cavity in three-dimensional reconstruction process - Google Patents

Abstract

The invention discloses a method for filling a cavity in a three-dimensional reconstruction process, which comprises the steps of determining a cavity filling area; acquiring a space geometric central point of the cavity; calculating the RGB mean value of the color around the hole and adding a random value of plus or minus 10 percent respectively; assigning the color value to the center point; judging whether the average distance from the central point to each peripheral vertex is smaller than the average distance between the vertexes; two TIN vertexes of the geometric center of the space and the edge of the cavity are connected one by one to form a new space area; generating a new TIN surface by the supplemented point cloud and the original point cloud around the cavity; starting from a TIN surface at the edge of the cavity, using the last line of pixels at the edge to perform color filling of the gradually changed TIN surface to the top color; and repeat this process until all TIN face color fills are complete. The invention carries out non-planar filling on the cavity by simulating the spatial change rate of the periphery of the cavity and carries out surface texture recovery by color polymerization of the surrounding environment so as to realize better effect than the traditional cavity filling mode.

Description

Method for filling cavity in three-dimensional reconstruction process

Technical Field

The invention relates to the technical field of three-dimensional reconstruction, in particular to a method for filling a cavity in a three-dimensional reconstruction process.

Background

Three-dimensional reconstruction refers to obtaining a three-dimensional model of an environment or an object through a series of processes based on a series of photographs of the environment or the object from different angles. The general expression thereof includes: point clouds, meshes, voxels, depth maps, etc.

The more common procedure is:

extracting image features (such as SIFT, SURF and the like);

calculating feature matching between the images by using the features;

performing sparse reconstruction based on the matched features to obtain camera poses of each image and sparse feature point clouds (SFM);

performing dense reconstruction based on the camera pose to obtain dense point cloud (PMVS/CMVS);

reconstructing a mesh, voxel or texture based on the point cloud;

because of the topography or the angle from which the image is taken, voids often exist in the final result, as shown in fig. 1.

In practical applications, the most common processing method for the holes is to supplement the holes as planes, and simply stretch the last row of pixels on the longest side of the holes to fill the holes, and the effect is shown in fig. 2: the filling effect is very stiff and stiff. In the conventional method, the holes are filled as an integral plane, which cannot be well consistent with the spatial variation information of the surrounding model, so that the final result looks rigid and stiff.

Based on this, it is necessary to develop a method for filling holes in the three-dimensional reconstruction process to solve the above problems.

Disclosure of Invention

The invention aims to solve the problems and designs a method for filling holes in a three-dimensional reconstruction process.

The invention realizes the purpose through the following technical scheme:

a method for filling holes in a three-dimensional reconstruction process comprises the following steps:

s1, determining a cavity filling area, and entering the next step;

s2, acquiring a space geometric central point of the cavity; calculating the RGB mean value of the surrounding color of the cavity and adding a random value of plus or minus 10 percent respectively; assigning the color value to the central point, and entering the next step;

s3, judging whether the average distance from the central point to each peripheral peak is smaller than the average distance between the peaks, if not, entering the step S4, and if so, entering the step S5;

s4, forming a new space region by the space geometric center and two TIN vertexes which are continuous with the edge of the cavity one by one, and entering the step S2;

s5, completing the supplement of the hollow point cloud, and entering the next step;

s6, generating a new TIN surface by the supplemented point cloud and the original point cloud around the cavity, and entering the next step;

s7, starting from the TIN surface at the edge of the cavity, using the last line of pixels at the edge to perform color filling of the gradually changed TIN surface to the top color; repeating the process until all the TIN surface color filling is completed, and entering the next step;

and S8, finishing the hole filling.

The invention has the beneficial effects that:

the method has the advantages that the non-planar filling is carried out on the cavity by simulating the space change rate of the periphery of the cavity, and the surface texture recovery is carried out through the color polymerization of the surrounding environment, so that the visual effect and the scene recovery effect which are better than those of the traditional cavity filling mode are realized, and the better display effect is achieved.

Drawings

FIG. 1 is a schematic diagram of a three-dimensional model in the prior art.

Fig. 2 is a schematic diagram of a three-dimensional model after filling a hole in the prior art.

Fig. 3 is a flow chart of the present application.

Fig. 4 is a first process flow diagram of the present application.

Fig. 5 is a process flow diagram of the present application.

FIG. 6 is a schematic diagram of a processing result of the present application, wherein A is a diagram illustrating an effect of repairing a hole according to the prior art; and B is an effect diagram after the cavity is repaired.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "inside", "outside", "left", "right", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships that the products of the present invention are conventionally placed in use, or the orientations or positional relationships that are conventionally understood by those skilled in the art, and are used for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is also to be noted that, unless otherwise explicitly stated or limited, the terms "disposed" and "connected" are to be interpreted broadly, and for example, "connected" may be a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; the connection may be direct or indirect via an intermediate medium, and may be a communication between the two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The following detailed description of embodiments of the invention refers to the accompanying drawings.

As shown in fig. 3, a method for filling a cavity in a three-dimensional reconstruction process includes the following steps:

s1, determining a cavity filling area, and entering the next step;

s2, acquiring a space geometric central point of the cavity; calculating the RGB mean value of the surrounding color of the cavity and adding a random value of plus or minus 10 percent respectively; assigning the color value to the central point, and entering the next step;

s3, judging whether the average distance from the central point to each peripheral peak is smaller than the average distance between the peaks, if not, entering the step S4, and if so, entering the step S5;

s4, forming a new space region by the two TIN vertexes of the space geometric center which are continuous with the edge of the cavity one by one, and entering the step S2;

s5, completing the supplement of the hollow point cloud, and entering the next step;

s6, generating a new TIN surface by the supplemented point cloud and the original point cloud around the cavity, and entering the next step;

s7, starting from the TIN surface at the edge of the cavity, using the last line of pixels at the edge to perform color filling of the gradually changed TIN surface to the top color; repeating the process until all the TIN surface color filling is completed, and entering the next step;

and S8, finishing the hole filling.

In some embodiments:

1. determining a hollow area. As shown in fig. 4: assuming that there is a hole, there are 7 spatial points around it, denoted p1-p7 respectively;

2. calculating the position c of the spatial center point of the color, and taking the color mean value of p1-p7 +/-10% as the color yc of the point c;

3. calculating the average distance L1 from the c point to p1-p7 and the average distance L2 between p1-p7 (the average value of the distance between p1 and p2, the distance between p2 and p3, the distance between p3 and p4, the distance between p4 and p5, the distance between p5 and p6, the distance between p6 and p7 and the distance between p7 and p 1), if L1 is less than or equal to L2, the completion of the supplementary space point is indicated, otherwise, the c point is respectively connected with p1-p7 to form 7 triangular surfaces;

4. the process of 2-3 is then repeated until all space complements are complete and all the complemented points have acquired a color with random properties.

The processes and results of steps 1-4 are shown in FIG. 4;

5. color overfilling from the edges of p1-p7 to the vertices of the triangle using colors on the connecting lines (the algorithm is very mature and not in the scope of the patent description);

6. filling step by step, finally reaching the central point c, and finishing the whole hole filling process.

The process of steps 5-6 is shown in figure 5.

As shown in FIG. 6, the results of comparing the processing of holes by the method of the present invention with the prior art are shown.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (1)

1. A method for filling a cavity in a three-dimensional reconstruction process is characterized by comprising the following steps:

s1, determining a cavity filling area, and entering the next step;

s2, acquiring a space geometric central point of the cavity; calculating the RGB mean value of the surrounding color of the cavity and adding a random value of plus or minus 10 percent respectively; assigning the color value to the central point, and entering the next step;

s3, judging whether the average distance between the central point and each peripheral peak is smaller than the average distance between the peaks, if not, entering the step S4, and if so, entering the step S5;

s4, forming a new space region by the two TIN vertexes of the space geometric center which are continuous with the edge of the cavity one by one, and entering the step S2;

s5, completing the supplement of the hollow point cloud, and entering the next step;

s6, generating a new TIN surface by the supplemented point cloud and the original point cloud around the cavity, and entering the next step;

s7, starting from the TIN surface at the edge of the cavity, using the last line of pixels at the edge to perform color filling of the gradually changed TIN surface to the top color; repeating the process until all the TIN surface color filling is completed, and entering the next step;

and S8, finishing the hole filling.

Images