CN106896690B - A holographic image evaluation method and device - Google Patents

Abstract

Embodiments of the present invention provide a method and device for evaluating a holographic image, which relate to the technical field of holographic display and are used for evaluating the surface morphology of a holographic image displayed by the holographic display technology. The method includes: dividing m holographic imaging layer signals of different depths in the holographic display signal into n holographic imaging layer signal groups of equal depths according to the depth of the holographic imaging layer; respectively displaying holographic images according to each holographic imaging layer signal group; Obtain the holographic cross-sectional images of the holographic images displayed by the signal groups of each holographic imaging layer in the depth direction of the holographic image; The coordinate value of each point on the contour evaluates the surface topography of the holographic image displayed by the holographic display signal. The embodiments of the present invention are used for evaluation of holographic images.

Description

A holographic image evaluation method and device

technical field

The invention relates to the technical field of holographic display, in particular to a method and device for evaluating a holographic image.

Background technique

With the development of display technology, users are no longer satisfied with flat display, so holographic display has received more and more attention. Holographic display technology is divided into: optical holography and computational holography (English name: Computer Generated Hologram, abbreviation: CGH) that uses digital computers to simulate, calculate, and process various optical processes. Among them, optical holography uses the interference principle of light to record the phase and amplitude information in the object light wave in the form of interference fringes by introducing a reference light wave coherent with the object light wave to interfere with the object light wave. The principle is to reproduce the original object light wave to form a 3D image of the original object. Computational holography is a technology that uses computers to design and produce holographic images. Different from optical holography, computational holography is based on broadcast diffraction algorithms to process mathematical descriptions or discrete data of recorded object waves. The realization process is: input the mathematical description function of the object light wave into the computer to simulate the actual interference process, calculate the interference fringes, draw the computational hologram, and then put the computational hologram into the actual optical path to obtain the reproduced image. Since optical holography requires a very stable optical system (no vibration, no noise) and light with high coherence and high intensity, its application range is greatly limited, while computational holography has low noise, good repeatability and can obtain The hologram of virtual objects and other notable features, so computational holography technology is the current research focus of holographic display technology.

Whether the surface topography of the holographic image displayed by the holographic display technology is the same as the surface topography of the holographic image required in the design is the core factor for evaluating the imaging quality of the holographic display technology. It is very important to evaluate the surface topography, however, there is no method for evaluating the surface topography of holographic images in the prior art.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a holographic image testing method and device, which are used to evaluate the surface topography of a holographic image displayed by a holographic display technology.

To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

In a first aspect, a holographic image evaluation method is provided, comprising:

According to the depth of the holographic imaging layer, m holographic imaging layer signals of different depths in the holographic display signal are divided into n holographic imaging layer signal groups of equal depth; where m and n are both positive integers, and m is greater than or equal to n ;

respectively displaying a holographic image according to each of the holographic imaging layer signal groups;

acquiring a holographic cross-sectional image of the holographic image displayed by each of the holographic imaging layer signal groups in the depth direction of the holographic image;

According to the coordinate value of each point on the outer contour of each holographic cross-sectional image and the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image, the surface shape of the holographic image displayed by the holographic display signal Appearance evaluation.

Optionally, according to the coordinate value of each point on the outer contour of each of the holographic cross-sectional images and the coordinate value of each point on the outer contour of the corresponding image layer in the designed holographic image, determine and display the surface topography of the holographic image. Is it the same as the surface topography of the designed holographic image, including:

Take any point in the plane where the outer contour of the holographic cross-sectional image is located as the origin to make a plurality of rays; wherein, the included angle of two adjacent rays is a preset value;

calculating the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image;

According to the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image and the coordinate value of the point corresponding to the intersection on the outer contour of the corresponding holographic imaging layer in the designed holographic image, determine the surface topography of the displayed holographic image Whether it is the same as the surface topography of the designed holographic image.

Optionally, the n is greater than or equal to 10 and less than or equal to 100.

Optionally, the multiple rays divide the outer contour of the holographic cross-sectional image into x parts, where x is an integer multiple of 3.

Optionally, the acquiring the holographic cross-sectional images displayed on the corresponding depth plane by each holographic image signal group includes:

The holographic cross-sectional images of each holographic image signal group displayed on the corresponding depth plane are obtained by shooting with a camera.

In a second aspect, a holographic image evaluation device is provided, comprising:

The display unit is used to divide m holographic imaging layer signals of different depths in the holographic display signal into n holographic imaging layer signal groups of equal depth according to the depth of the holographic imaging layer, and respectively according to the holographic imaging layer signal groups of each said holographic imaging layer Display a holographic image; wherein, m and n are both positive integers, and m is greater than or equal to n;

an acquisition unit, configured to acquire, in the depth direction of the holographic image, a holographic cross-sectional image of the holographic image displayed by each of the holographic imaging layer signal groups;

The processing unit, according to the coordinate value of each point on the outer contour of each holographic cross-sectional image and the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image, displays the holographic image for the holographic display signal The surface morphology was evaluated.

Optionally, the processing unit is specifically configured to take any point in the plane where the outer contour of the holographic cross-sectional image is located as the origin to make multiple rays, and calculate the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image, According to the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image and the coordinate value of the intersection of each ray and the outer contour of the corresponding holographic imaging layer in the designed holographic image, determine the surface topography of the displayed holographic image and the designed holographic image whether the surface morphology is the same.

Optionally, the n is greater than or equal to 10 and less than or equal to 100.

Optionally, the multiple rays divide the outer contour of the holographic cross-sectional image into x parts, where x is an integer multiple of 3.

Optionally, the display unit is a display screen or a spatial light modulator;

The acquisition unit is a camera located in the depth direction of the holographic image.

In the holographic image evaluation method provided by the embodiment of the present invention, firstly, according to the depth of the holographic imaging layer, m holographic imaging layer signals of different depths in the holographic display signal are divided into n holographic imaging layer signal groups of equal depth, and according to each The holographic imaging layer signal group displays a holographic image, then acquires holographic cross-sectional images of the holographic images displayed by each of the holographic imaging layer signal groups in the depth direction of the holographic image, and finally according to the outer contour of each holographic cross-sectional image The coordinate value of each point on the holographic image and the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image are used to evaluate the surface morphology of the holographic image displayed by the holographic display signal, that is, the embodiment of the present invention. A method for evaluating the surface topography of a holographic image is provided.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a flow chart of the steps of a holographic image evaluation method provided by an embodiment of the present invention;

2 is a schematic diagram of a holographic image provided by an embodiment of the present invention;

3 is a schematic diagram of a holographic imaging layer provided by an embodiment of the present invention;

4 is a schematic diagram of an execution body of a holographic image evaluation method provided by an embodiment of the present invention;

5 is a schematic diagram of a cross-sectional image provided by an embodiment of the present invention;

6 is a schematic diagram of an intersection of a ray and an outer contour provided by an embodiment of the present invention;

7 is a three-dimensional grid diagram of a holographic image provided by an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a holographic image evaluation device provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

An embodiment of the present invention provides a holographic image evaluation method. Specifically, as shown in FIG. 1 , the holographic image evaluation method includes the following steps:

S11. Divide m holographic imaging layer signals of different depths in the holographic display signal into n holographic imaging layer signal groups of equal depths according to the depth of the holographic imaging layer.

Among them, m and n are both positive integers, and m is greater than or equal to n.

Illustratively, as shown in FIG. 2 , in FIG. 2 , step S11 in the above-mentioned holographic image testing method is described by taking the holographic display signal for displaying a spherical holographic image as an example.

As shown in Fig. 2, the holographic image includes m holographic imaging layers (holographic imaging layer 1, holographic imaging layer 2... holographic imaging layer m), wherein the holographic image displayed by the holographic imaging layer 1 and the holographic image displayed by the holographic imaging layer m The image is a cone (as shown in a in Figure 3), and the holographic images displayed by the other holographic imaging layers are all truncated cones (as shown in b in Figure 3). In addition, from the holographic imaging layer 1 to the holographic imaging layer m The depths of the m holographic imaging layers increase sequentially, and the m holographic imaging layers correspond to one holographic imaging layer signal respectively.

Exemplarily, if the holographic image signal includes 400 holographic imaging layers, and the holographic image signal is divided into 50 holographic imaging layer signal groups of equal depth, then any holographic image signal group includes 8 adjacent holographic imaging layers. . Specifically, the holographic images corresponding to the first holographic image signal group include: holographic imaging layer 1 to holographic imaging layer 8; the holographic images corresponding to the second holographic image signal group include: holographic imaging layer 9 to holographic imaging layer 16; The holographic images corresponding to the 50 holographic image signal groups include: the holographic imaging layer 393 to the holographic imaging layer 400 .

It should be noted that, in the above embodiment, the holographic image display signal displays a spherical holographic image as an example for description, but the embodiment of the present invention is not limited to this. Any shape holographic image signal (for example: ellipsoid, truncated cone, cone and other irregular shapes) can be divided into n holographic imaging layer signals of m different depths in the holographic display signal according to the depth of the holographic imaging layer Holographic imaging layer signal group of equal depth.

Optionally, n in the foregoing embodiment is greater than or equal to 10 and less than or equal to 100. That is, in the above embodiment, m holographic imaging layer signals of different depths in the holographic display signal may be divided into 10-100 holographic imaging layer signal groups of equal depth according to the depth of the holographic imaging layer.

S12. Display a holographic image according to each holographic imaging layer signal group.

Optionally, displaying the holographic image according to each holographic imaging layer signal group may specifically include: sequentially displaying the holographic image in each holographic imaging layer signal group according to the depth of the holographic imaging layer. Of course, holographic images can also be displayed according to each holographic imaging layer signal group according to other display sequences. In the embodiment of the present invention, the order in which each holographic imaging layer signal group displays holographic images is not limited, and all holographic imaging layer signal groups can be The holographic images are displayed independently respectively.

S13: Acquire a holographic cross-sectional image of the holographic image displayed by each holographic imaging layer signal group in the depth direction of the holographic image.

Exemplarily, as shown in FIG. 4 , a holographic image can be displayed by a holographic image display device 41 (display or spatial light modulator), and a camera 42 is set in the depth direction of the holographic image, and the camera 42 is used for focusing and shooting to obtain each image. The holographic cross-sectional image of the holographic image displayed by the holographic imaging layer signal group.

Exemplarily, as shown in FIG. 5 , the holographic cross-sectional images corresponding to the cone a and the frustum b in FIG. 3 are divided into circles (shown in a in FIG. 5 ) and rings (shown in b in FIG. 5 ).

S14, according to the coordinate value of each point on the outer contour of each holographic cross-sectional image and the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image, carry out the surface topography of the holographic image displayed by the holographic display signal. Evaluation.

Exemplarily, step 14 can be specifically implemented in the following manner:

1. Print out the holographic images used for the pair of n holographic image signal groups according to the actual size.

Ⅱ. Put the printed holographic images at the corresponding image depths, and use an industrial camera to focus and shoot.

Ⅲ. Compare the coordinate value of each point on the outer contour of the picture with different depths and the coordinate value of each point on the outer contour of the corresponding holographic cross-sectional image, and then according to the coordinates of each point on the outer contour of the picture with different depths The difference between the value and the coordinate value of each point on the outer contour of the holographic cross-sectional image is used to evaluate the surface topography of the holographic image displayed by the holographic display signal.

In addition, it should also be noted that since there will be certain errors in the display and measurement processes, it is not required that the holographic cross-sectional image is determined when the surface topography of the displayed holographic image is determined to be the same as the surface topography of the designed holographic image in the above-mentioned embodiment. The coordinate value of each point on the outer contour of the holographic image is exactly the same as the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image, but the coordinate value of each point on the outer contour of the holographic cross-sectional image is required to be the same as The coordinate values of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image are within a certain range. The specific range may be set according to a specific display device, an industrial camera, a holographic image, and an evaluation requirement, which is not limited in this embodiment of the present invention.

In the holographic image evaluation method provided by the embodiment of the present invention, firstly, according to the depth of the holographic imaging layer, m holographic imaging layer signals of different depths in the holographic display signal are divided into n holographic imaging layer signal groups of equal depth, and according to each The holographic imaging layer signal group displays the holographic image, and then acquires the holographic cross-sectional image of the holographic image displayed by each holographic imaging layer signal group in the depth direction of the holographic image, and finally, according to the coordinate value of each point on the outer contour of each holographic cross-sectional image and the The coordinate values of each point on the outer contour of the corresponding holographic imaging layer in the holographic image are designed to evaluate the surface morphology of the holographic image displayed by the holographic display signal, that is, the embodiment of the present invention provides a surface A method for evaluating morphology.

Further, the embodiment of the present invention also provides an implementation manner of the foregoing step S14. Specifically, in the above step S14, according to the coordinate values of each point on the outer contour of each holographic cross-sectional image and the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image, the holographic image displayed by the holographic display signal is The surface topography to be evaluated includes:

S141 , taking any point in the plane where the outer contour of the holographic cross-sectional image is located as the origin to create a plurality of rays.

Wherein, the included angle of two adjacent rays is a preset value.

Exemplarily, the embodiment of the present invention will be described below by taking the holographic cross-sectional image as a ring and the center of the ring as the origin as a ray, and the angle between two adjacent rays is 30°. Specifically, as shown in FIG. 6, taking the center O of the ring as the origin, 12 rays (ray 1 to ray 12) are made, and two adjacent rays (for example: ray 1 and ray 2, ray 12) are adjacent to each other. The included angles with rays L, etc.) are all 30°, and the 12 rays have 12 intersection points (point A to point L) with the outer contour (outer circle of the ring) of the holographic cross-sectional image.

It should be noted that when the holographic image is an irregular figure, the principle of the overall image evaluation method is the same. Then make multiple rays according to the origin to determine the intersection point, and obtain the coordinate value of the intersection point between the ray and the outer contour, and finally compare the coordinate value of each intersection point with the theoretical value to evaluate the imaging quality of the holographic image.

S142: Calculate the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image.

That is, the coordinate values of point A, point B, point C, point D, point E, point F, point G, point H, point I, point J, point K, and point L are calculated respectively.

S143, according to the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image and the coordinate value of the point corresponding to the intersection on the outer contour of the corresponding holographic imaging layer in the designed holographic image, determine the surface topography of the displayed holographic image and the designed holographic image whether the surface morphology is the same.

Further, as shown in FIG. 7 , sequentially connect the holographic image corresponding to the first holographic image signal group to the point a on the outer contour of the cross-sectional image of the holographic image corresponding to the nth holographic image signal group, and the first holographic image Connect the holographic image corresponding to the image signal group to the point b on the outer contour of the holographic image corresponding to the nth holographic image signal group, until the holographic image corresponding to the first holographic image signal group is connected to the nth holographic image signal group. If the points L on the outer contour of the corresponding holographic image are connected, 12 closed figures can be obtained on the spherical holographic image, and the 12 closed figures and the outer contour of the cross-sectional image of the holographic image corresponding to each holographic image signal group can be obtained. A three-dimensional grid map is formed on the holographic image.

Optionally, the multiple rays divide the outer contour of the holographic cross-sectional image into x parts, where x is an integer multiple of 3. Exemplarily, x may be 12, 24, 36, or the like.

Setting x to be an integer multiple of 3 can simplify the subsequent calculation of determining the surface topography of the holographic image.

Yet another embodiment of the present invention provides a holographic image evaluation device corresponding to the holographic image evaluation method provided by the above-mentioned embodiments. Specifically, as shown in FIG. 8 , the holographic image evaluation device 800 includes:

The display unit 81 is configured to divide m holographic imaging layer signals of different depths in the holographic display signal into n holographic imaging layer signal groups of equal depth according to the depth of the holographic imaging layer, and display the signals according to each holographic imaging layer signal group respectively. Holographic image.

Among them, m and n are both positive integers, and m is greater than or equal to n.

The acquiring unit 82 is configured to acquire, in the depth direction of the holographic image, the holographic cross-sectional image of the holographic image displayed by each holographic imaging layer signal group.

The processing unit 83 , according to the coordinate value of each point on the outer contour of each holographic cross-sectional image and the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image, analyzes the surface shape of the holographic image displayed by the holographic display signal. Appearance evaluation.

Optionally, the processing unit 83 is specifically used to make multiple rays with any point in the plane where the outer contour of the holographic cross-sectional image is located as the origin, and calculate the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image. The coordinate value of the intersection of the outer contour of the cross-sectional image and the coordinate value of the intersection of each ray and the outer contour of the corresponding holographic imaging layer in the designed holographic image is used to determine whether the surface topography of the displayed holographic image is the same as that of the designed holographic image.

Optionally, n is greater than or equal to 10 and less than or equal to 100.

Optionally, the multiple rays divide the outer contour of the holographic cross-sectional image into x parts, where x is an integer multiple of 3.

Optionally, as shown in FIG. 4 , the display unit 81 is a display screen or a spatial light modulator;

The acquisition unit 82 is a camera located in the depth direction of the holographic image.

It should be noted that the design principle of the holographic image evaluation method provided above is exactly the same as the design principle of the holographic image evaluation device provided by the embodiment of the present invention, so all the explanations in the holographic image evaluation method provided by the above embodiment can be cited to the holographic image evaluation device provided by the embodiment of the present invention.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical scope disclosed by the present invention can easily think of changes or substitutions. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (10)

1. a holographic image evaluation method, is characterized in that, comprises: According to the depth of the holographic imaging layer, m holographic imaging layer signals of different depths in the holographic display signal are divided into n holographic imaging layer signal groups of equal depth; where m and n are both positive integers, and m is greater than or equal to n ; respectively displaying a holographic image according to each of the holographic imaging layer signal groups; acquiring a holographic cross-sectional image of the holographic image displayed by each of the holographic imaging layer signal groups in the depth direction of the holographic image; According to the coordinate value of each point on the outer contour of each holographic cross-sectional image and the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image, the surface shape of the holographic image displayed by the holographic display signal Appearance evaluation. 2 . The method according to claim 1 , wherein the coordinate value of each point on the outer contour of each of the holographic cross-sectional images and each point on the outer contour of the corresponding image layer in the designed holographic image The coordinate value of judging whether the surface morphology of the displayed holographic image is the same as that of the designed holographic image, including: Take any point in the plane where the outer contour of the holographic cross-sectional image is located as the origin to make a plurality of rays; wherein, the included angle of two adjacent rays is a preset value; calculating the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image; According to the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image and the coordinate value of the point corresponding to the intersection on the outer contour of the corresponding holographic imaging layer in the designed holographic image, determine the surface topography of the displayed holographic image Whether it is the same as the surface topography of the designed holographic image. 3 . The method of claim 1 , wherein the n is greater than or equal to 10 and less than or equal to 100. 4 . 4 . The method according to claim 2 , wherein the multiple rays divide the outer contour of the holographic cross-sectional image into x parts, and the x is an integer multiple of 3. 5 . 5. The method according to claim 2, wherein the acquiring the holographic cross-sectional images of each holographic image signal group displayed on the corresponding depth plane comprises: The holographic cross-sectional images of each holographic image signal group displayed on the corresponding depth plane are obtained by shooting with a camera. 6. A holographic image evaluation device, comprising: The display unit is used to divide m holographic imaging layer signals of different depths in the holographic display signal into n holographic imaging layer signal groups of equal depth according to the depth of the holographic imaging layer, and respectively according to the holographic imaging layer signal group of each said holographic imaging layer Display a holographic image; wherein, m and n are both positive integers, and m is greater than or equal to n; an acquisition unit, configured to acquire, in the depth direction of the holographic image, a holographic cross-sectional image of the holographic image displayed by each of the holographic imaging layer signal groups; The processing unit, according to the coordinate value of each point on the outer contour of each holographic cross-sectional image and the coordinate value of each point on the outer contour of the corresponding holographic imaging layer in the designed holographic image, displays the holographic image for the holographic display signal The surface morphology was evaluated. 7 . The device according to claim 6 , wherein the processing unit is specifically configured to use any point in the plane where the outer contour of the holographic cross-sectional image is located as an origin to make multiple rays, and calculate the relationship between each ray and the holographic image. 8 . The coordinate value of the intersection of the outer contour of the cross-sectional image is determined according to the coordinate value of the intersection of each ray and the outer contour of the holographic cross-sectional image and the coordinate value of the intersection of each ray and the outer contour of the corresponding holographic imaging layer in the designed holographic image. Whether the surface topography of the displayed holographic image is the same as that of the designed holographic image. 8 . The device of claim 6 , wherein the n is greater than or equal to 10 and less than or equal to 100. 9 . 9 . The device according to claim 7 , wherein the multiple rays divide the outer contour of the holographic cross-sectional image into x parts, and the x is an integer multiple of 3. 10 . 10. The device of claim 6, wherein: The display unit is a display screen or a spatial light modulator; The acquisition unit is a camera located in the depth direction of the holographic image.