WO2019219092A1

WO2019219092A1 - Single-screen circumferential-translation bitmap-type volume display method

Info

Publication number: WO2019219092A1
Application number: PCT/CN2019/087739
Authority: WO
Inventors: 李立新
Original assignee: 浙江大学
Priority date: 2018-05-17
Filing date: 2019-05-21
Publication date: 2019-11-21
Also published as: CN108769663A; CN108769663B

Abstract

Disclosed is a single-screen circumferential-translation bitmap-type volume display method. An imaging screen which performs circumferential translation motion is provided; a two-dimensional image representing a cross section of a three-dimensional scene is displayed on the imaging screen; and bitmap information of the two-dimensional image and the display position of the two-dimensional image on the imaging screen are dynamically refreshed according to the real-time position of the imaging screen, so as to form a time-division two-dimensional image sequence having parallel images; by means of visual persistence effect, the two-dimensional image sequence is perceived and restored to a three-dimensional scene by an observer. Compared to the display method in the background art, the present invention significantly simplifies the driving mechanism and improves the duty cycle of the display space and the duty cycle of the display time under the premise of ensuring uniform voxels and achieving inertial force balance. Therefore, the present invention is particularly suitable for precise display of three-dimensional images, and has wide application prospects in the field relating to three-dimensional image display, such as industrial design, scientific research, teaching presentation, medical CT analysis, and spatial mechanism motion simulation.

Description

Single screen circular translation bitmap type volume display method

Technical field

The invention relates to a three-dimensional image display method, in particular to a single-screen circular translation bitmap volume display method.

Background technique

The disclosed bitmap volume display method can be respectively assigned to three types: fixed-axis rotary type, reciprocating type and multi-screen translation type according to the number of imaging screens and the mechanical scanning movement mode thereof.

The fixed axis rotation type is shown in Fig. 1. There is only one imaging screen, and the mechanical scanning motion of the imaging screen is a fixed axis rotation. The advantage is that the inertial force is easy to balance, and the duty ratio of the display space and the duty ratio of the display time are maximized; the limitation is that the size and distribution of the voxels are not uniform, but linearly increases from the outer axis of the rotation, and thus Suitable for accurate display of 3D images.

The reciprocating movement is shown in Fig. 2. There is only one imaging screen, and the mechanical scanning motion of the imaging screen is reciprocating. The advantage is that voxels with uniform size and uniform distribution are allowed, so as to be suitable for accurate display of three-dimensional images, and the duty ratio of display space and display time are relatively large; the limitation is that the motion of the imaging screen is very large. The reciprocating motion, the inertial force cannot be balanced, and the vibration and noise problems caused are difficult to overcome.

The multi-screen translation type is shown in Fig. 3. Among them, there are 2 to 6 parallel imaging images which are evenly distributed on the same circumference, and are circumferentially translated along the circumference, and sequentially appear in the field of view. The advantage is that it allows voxels of uniform size and uniform distribution, so as to be suitable for accurate display of three-dimensional images, and the inertial force can be balanced; the limitation is that the duty ratio of display space and the duty ratio of display time are relatively small, especially driving The organization is more complicated.

Summary of the invention

In order to overcome the problems in the background art, it is an object of the present invention to provide a single screen circumferential translation bitmap volume display method.

The technical solution adopted by the present invention to solve the technical problem thereof is:

The invention has an imaging screen for circumferential translation, and displays a two-dimensional image representing a cross section of the three-dimensional scene on the imaging screen, the bitmap information of the two-dimensional image and its display position on the imaging screen, according to the imaging screen The real-time position is dynamically refreshed to form a parallel, time-division two-dimensional image sequence; with the visual persistence effect, the two-dimensional image sequence is perceived by the observer and restored to a three-dimensional scene.

A method for displaying a two-dimensional image representing a cross section of a three-dimensional scene on the imaging screen is generated by direct display; to achieve circular translation of the imaging screen, a first parallelogram mechanism is adopted, wherein the connecting rod and the imaging In order to achieve the balance with the inertial force of the first parallelogram mechanism, the first weight parallelogram mechanism with a crank arrangement of 180° is adopted, and the crank arrangement of 180° refers to the first weight parallelogram mechanism. The crank and the crank of the first parallelogram mechanism are arranged symmetrically on both sides to form a 180° arrangement, wherein the connecting rod is fixedly connected to the first weight; in order to ensure that the two-dimensional image displayed on the imaging screen falls exactly on the fixed imaging In space, it is necessary to make the offset of the display bitmap relative to the imaging screen equal to the amount of displacement of the imaging screen in the direction of the screen.

A method for displaying a two-dimensional image representing a cross section of a three-dimensional scene on the imaging screen is generated by projection imaging; and a mirror for circumferential translation is disposed on a projection light path from the fixed projector to the imaging screen. For the circumferential translation, the translation is performed along the circumferential path; between the mirror for the translation of the circumference and the imaging screen for the circumferential translation, a fixed mirror is installed to adjust the direction of the optical path; Zhou Pingdong, the first parallelogram mechanism is adopted, in which the connecting rod is fixedly connected with the imaging screen; in order to achieve the balance of the inertial force with the first parallelogram mechanism, the first weight with the crank arranged at 180° is used in parallel. The quadrilateral mechanism, the crank is 180°, which means that the crank of the first counterweight parallelogram mechanism and the crank of the first parallelogram mechanism are arranged symmetrically on both sides to form a 180° arrangement, wherein the connecting rod and the first weight are fixed. In order to realize the circular translation of the mirror, a second parallelogram mechanism is adopted, in which the connecting rod is fixedly connected with the mirror; to achieve the flatness of the inertial force with the second parallelogram mechanism The second counterweight parallelogram mechanism with a crank arrangement of 180° is adopted, and the crank arrangement of 180° means that the crank of the second counterweight parallelogram mechanism and the crank of the second parallelogram mechanism are symmetrically arranged on both sides. 180° arrangement in which the connecting rod is fixed to the second weight; the crank length of the first parallelogram mechanism must be twice the crank length of the second parallelogram mechanism, and the first parallelogram mechanism has one The crank is fixed to a crank of the second parallelogram mechanism, so that the linear velocity of the mirror in the vertical mirror direction is always half of the linear velocity of the imaging screen in the vertical screen direction, thereby ensuring from fixing the projector to The optical path between the imaging screens that are circularly moved remains unchanged, and a two-dimensional image with sharp focus, the same size, and a position just in the fixed imaging space is projected on the imaging screen.

The invention has the beneficial effects of:

The invention is similar to the reciprocating type and the multi-screen translation type. In the process of circularly moving the imaging screen, the positions are parallel to each other, thereby allowing voxels of uniform size and uniform distribution, thereby being suitable for accurate display of three-dimensional images and display. The three-dimensional image quality is inevitably better than the fixed-axis rotation type; secondly, compared with the reciprocating movement type, the invention avoids the reciprocating motion with large acceleration, and can realize the inertial force balance; compared with the multi-screen translation type, it is significantly simplified. The drive mechanism is increased, and the duty ratio of the display space and the duty ratio of the display time are increased.

The invention is particularly suitable for accurate display of three-dimensional images, and has broad application prospects in the fields of industrial design, scientific research, teaching demonstration, medical CT analysis, spatial mechanism motion simulation and the like, involving three-dimensional image display.

DRAWINGS

1 is a schematic diagram of a known method of setting a fixed-axis rotational bitmap volume.

2 is a schematic diagram of a known reciprocating bitmap volume display method.

3 is a schematic diagram of a known multi-screen translational bitmap volume display method.

4 is a schematic diagram of a single screen circumferential translation bitmap volume display method of the present invention.

Fig. 5 is a view showing the state of the first embodiment of the present invention.

Figure 6 is a schematic view showing the state of the second embodiment of the present invention.

Fig. 7 is a second schematic view showing the state of the first embodiment of the present invention.

Figure 8 is a second schematic view of the second embodiment of the present invention.

In the picture: 1, imaging screen, 1 ', counterweight, 2, mirror, 3, fixed mirror, 4, projector.

Detailed ways

The invention will now be further described with reference to the accompanying drawings and embodiments.

1 is a schematic diagram of a known method of setting a fixed-axis rotational bitmap volume. The imaging screen 1 is rotated in a fixed axis, and the inertial force is easily balanced. The imaging space of the imaging screen 1 (shown by gray shading, the same below) can be equivalent to the scanning space (shown by the hatching, the same below), and thus the display space is occupied. The space ratio reaches a maximum of 100%; from the time duty cycle, a two-dimensional image is displayed at any time, and the duty ratio of time also reaches a maximum of 100%. In such a method, the size of the imaging screen 1 may be equal to the size of the two-dimensional cross-sectional image; if the two-dimensional cross-sectional image is rectangular, the three-dimensional imaging space is a cylinder.

2 is a schematic diagram of a known reciprocating bitmap volume display method. The imaging screen 1 is reciprocatingly moved by the shifting speed, and the inertial force cannot be balanced. Considering that the acceleration at both ends is large, it is not conducive to imaging. The imaging space of the imaging screen 1 is usually smaller than the scanning space, and thus the duty ratio of the display space. The duty cycle with the display time is less than 100%. In such a method, the size of the imaging screen 1 may be equal to the size of the two-dimensional cross-sectional image; if the two-dimensional cross-sectional image is rectangular, the three-dimensional imaging space is a rectangular parallelepiped.

3 is a schematic diagram of a known multi-screen translational bitmap volume display method, in which a solid black solid line indicates an imaging screen 1, and a circular dashed line indicates a path of three imaging screens 1 for circular translation, hatching The area is a three-dimensional scanning space formed by the circular imaging of the three imaging screens 1 , and the area where the gray shadow is located is an imaging space formed by the three imaging screens 1 as a circular motion. It shows the case where the three imaging screens 1 are evenly distributed on the same circumference and sequentially enter the field of view. In such a method, the imaging space of the imaging screen 1 is much smaller than the scanning space, and when two imaging screens in the imaging space are alternated, the two-dimensional image cannot be displayed, and thus the duty ratio of the display space and the duty ratio of the display time Both are relatively small. If the imaging space is required to be a rectangular parallelepiped, the size of the imaging screen 1 must be larger than the size of the two-dimensional sectional image of the imaging space.

4 is a schematic diagram of a single-screen circular translation bitmap volume display method of the present invention. In the figure, a thick black solid line indicates the imaging screen 1, and a circular dotted line indicates a path of the imaging screen 1 for circular translation, and the section line is located. The area is a three-dimensional scanning space formed by the circumferential translation of the imaging screen 1. The area where the gray shadow is located is a three-dimensional imaging space formed by the imaging screen 1 and which can always display a three-dimensional scene. There is an imaging screen 1 for circular translation; a two-dimensional image representing a cross section of the three-dimensional scene is displayed on the imaging screen 1, and the bitmap information of the two-dimensional image and its display position on the imaging screen 1 are based on imaging The real-time position of the screen 1 is dynamically refreshed to form a parallel, time-division two-dimensional image sequence; with the visual persistence effect, the two-dimensional image sequence is perceived and restored by the observer into a three-dimensional scene. In this method, the imaging space of the imaging screen 1 is also smaller than the scanning space, but the duty ratio of the display space is larger than that of FIG. 3, and the duty ratio of the display time is the same as that of FIG. If the imaging space is required to be a rectangular parallelepiped, the width of the imaging screen 1 is at least twice greater than the width of the two-dimensional cross-sectional image, that is, the horizontal horizontal length of the imaging screen 1 in FIG. 4 is at least greater than the horizontal shading length of the region in the figure. double.

5 and FIG. 7 are the first embodiment of the present invention. In the figure, a thick black solid line indicates the imaging screen 1, and a circular dotted line indicates a path in which the imaging screen 1 is circumferentially translated. The area where the hatching is located is the imaging screen 1. The three-dimensional scanning space formed by the circumferential translation, the area where the gray shadow is located is a three-dimensional imaging space formed by the imaging screen 1 under the circumferential translation, which can always display the three-dimensional scene. A method for displaying a two-dimensional image representing a cross section of a three-dimensional scene on the imaging screen 1 is generated by direct display; to realize the circumferential translation of the imaging screen 1, a first parallelogram mechanism ABCD is adopted, The rod BC is fixedly connected to the imaging screen 1; in order to achieve the balance of the ABCD inertia force with the first parallelogram mechanism, the first weight parallelogram mechanism AB'C'D with the crank arranged at 180° is used, wherein the rod B'C' is fixed with the first weight 1'; in the specific implementation, the link B'C' and the first weight 1' can be directly decomposed to point B' and point C', becoming two An independent weight; in order to ensure that the two-dimensional image displayed on the imaging screen 1 falls exactly in the fixed imaging space, the offset of the display bitmap relative to the imaging screen must be equal to the displacement of the imaging screen in the direction of the screen. .

6 and FIG. 8 are a second embodiment of the present invention. In the figure, the solid black solid lines respectively represent the imaging screen 1/mirror 2, and the circular dotted line indicates the path of the imaging screen 1/mirror 2 for circumferential translation. The area corresponding to the section line of the imaging screen 1 is a three-dimensional scanning space formed by the circular motion of the imaging screen 1. The gray shading area corresponding to the imaging screen 1 is a three-dimensional scene formed by the imaging screen 1 and can be displayed under the circular motion. In the imaging space, the area corresponding to the section line of the mirror 2 is a three-dimensional moving space formed by the mirror 2, and the corresponding gray shading area of the mirror 2 is the reflection projection formed by the mirror 2 under the circular motion. The three-dimensional imaging space of the instrument imaging. A method of displaying a two-dimensional image representing a cross section of a three-dimensional scene on the imaging screen 1 is generated by projection imaging; and a circumferential translation is provided on a projection light path from the fixed projector 4 to the imaging screen 1. Mirror 2; between the mirror 2 for circumferential translation and the imaging screen 1 for circumferential translation, a fixed mirror 3 is mounted, and the fixed mirror 3 is fixed in position to adjust the direction of the optical path; The circumferential translation of 1 adopts the first parallelogram mechanism ABCD, in which the connecting rod BC is fixedly connected to the imaging screen 1; in order to achieve the balance of the inertial force of the ABCD with the first parallelogram mechanism, the crank is arranged at 180°. The first counterweight parallelogram mechanism, wherein the connecting rod is fixedly connected to the first weight (similar to the structure of Fig. 5, not shown in Fig. 6); in order to realize the circular translation of the mirror 2, the first Two parallelogram mechanisms AEFG, wherein the connecting rod EF is fixedly connected with the mirror 2; in order to achieve the balance of the inertial force of the AEFG with the second parallelogram mechanism, a second counterweight parallelogram mechanism with a crank arrangement of 180° is used. , the connecting rod and the first A counterweight secured (FIG. 5 and similar structure, not shown in FIG. 6).

The imaging light emitted by the projector 4 is sequentially reflected by the mirror 2, reflected by the fixed mirror 3, and then irradiated onto the imaging screen 1. The embodied imaging screen 1 may be a white screen but is not limited thereto. The crank length |AB| of the first parallelogram mechanism ABCD must be twice the crank length |AE| of the second parallelogram mechanism, that is, the circumference diameter of the imaging screen 1 for the circumferential translation is the mirror 3 for the circumferential translation The diameter of the circumference is twice, and the first parallelogram mechanism has a crank AB fixed to a crank AE of the second parallelogram mechanism, so that the linear velocity of the mirror 2 in the vertical mirror direction is always maintained as an image screen. 1 half the linear velocity in the direction of the vertical screen, thereby ensuring that the optical path from the fixed projector 4 to the imaging screen 1 for the circumferential translation remains unchanged, and the focus is clear and the same size is projected on the imaging screen. A two-dimensional image that is positioned exactly in a fixed imaging space.

As shown in FIG. 6 and FIG. 7, the first parallelogram mechanism has a crank AB and a crank AE of the second parallelogram mechanism is vertically fixed at 90°, but the specific implementation is not limited to this 90° vertical, and may be other Any angle of attachment.

The above-mentioned embodiments are intended to be illustrative of the present invention, and are not intended to limit the scope of the invention, and any modifications and changes may be made without departing from the scope of the invention.

Claims

A single-screen circular translation bitmap volume display method, characterized in that: there is an imaging screen for circumferential translation, and a two-dimensional image representing a cross-section of a three-dimensional scene is displayed on the imaging screen, the two-dimensional image The bitmap information and its display position on the imaging screen are dynamically refreshed according to the real-time position of the imaging screen to form a parallel, time-division two-dimensional image sequence; the two-dimensional image sequence is observed by the visual persistence effect Perceive and revert to a 3D scene.
A single-screen circular translation bitmap volume display method according to claim 1, wherein a method for displaying a two-dimensional image representing a cross-section of a three-dimensional scene on the imaging screen is generated by direct display. In order to realize the circumferential translation of the imaging screen, the first parallelogram mechanism is adopted, wherein the connecting rod is fixedly connected with the imaging screen (1); in order to achieve the balance of the inertial force with the first parallelogram mechanism, the crank is presented. The first counterweight parallelogram mechanism arranged at 180°, wherein the connecting rod is fixedly connected to the first weight (1'); in order to ensure that the two-dimensional image displayed on the imaging screen falls exactly in the fixed imaging space, it is necessary The offset of the display bitmap relative to the imaging screen is equal to the amount of displacement of the imaging screen in the direction of the screen.
A single-screen circular translation bitmap volume display method according to claim 1, wherein a method for displaying a two-dimensional image representing a cross section of a three-dimensional scene on the imaging screen is generated by projection imaging. a mirror for circumferential translation is provided on the projection light path from the fixed projector to the imaging screen; a fixed mirror is mounted between the mirror for the circumferential translation and the imaging screen for the circumferential translation In order to adjust the direction of the optical path; in order to achieve the circular translation of the imaging screen, the first parallelogram mechanism is adopted, wherein the connecting rod is fixedly connected with the imaging screen (1); to achieve the inertial force with the first parallelogram mechanism Balanced, the first counterweight parallelogram mechanism with a crank arrangement of 180° is adopted, wherein the connecting rod is fixedly connected with the first weight (1'); for the circumferential translation of the mirror, a second one is adopted. a parallelogram mechanism, wherein the connecting rod is fixedly connected with the mirror (2); to achieve balance with the inertial force of the second parallelogram mechanism, a second weight parallelogram mechanism with a crank arrangement of 180° is used, wherein even Coupling with the second weight; the length of the crank of the first parallelogram mechanism must be twice the length of the crank of the second parallelogram mechanism, and the first parallelogram mechanism has a crank and a second parallelogram mechanism One of the cranks is fixed so that the linear velocity of the mirror in the vertical mirror direction is always half of the linear velocity of the imaging screen in the vertical screen direction, thereby ensuring the imaging screen from the fixed projector to the circumferential translation. The optical path between the two remains unchanged, and a two-dimensional image with sharp focus, the same size, and a position just in the fixed imaging space is projected on the imaging screen.