Method for reducing 3D crosstalk and 3D display

Abstract

The present invention provides a method for reducing 3D crosstalk and a 3D display. The method includes: detecting a first eye position and a second eye position of a user, and determining a viewing angle of the user and a rotation angle of the user's head based thereon; estimating a first reference position and a first midpoint position between the first eye and the second eye of the user based on the first eye position and the second eye position of the user; obtaining a second reference position, and estimating a difference amount between the first reference position and the second reference position; correcting the first midpoint position to a second midpoint position based on the rotation angle and the difference amount of the user; and determining a first pixel for projecting to the first eye of the user and a second pixel for projecting to the second eye of the user among a plurality of pixels of the 3D display based on the second midpoint position. Accordingly, the present invention can correspondingly reduce the situation of 3D crosstalk, and further improve the user experience of viewing the 3D display.

Description

Technical Field

[0001] The present invention relates to a 3D display technology, and more particularly to a method for reducing 3D crosstalk and a 3D display. Background Art

[0002] Current autostereoscopic 3D displays first place the pixels of the left and right eyes at the corresponding pixel positions on the display panel, and then control the light path through the liquid crystal in the 3D lens to project the left and right eye images onto the corresponding eyes respectively. Since it is necessary to focus on the left and right eyes, the 3D lens usually has a curved design so that the left (right) eye image can be focused and projected into the left (right) eye. However, limited by the refraction light path, some light rays may be projected into the wrong eye. That is to say, the left (right) eye image runs into the right (left) eye, and this phenomenon is called 3D crosstalk.

[0003] Generally, an autostereoscopic 3D display usually configures an eye tracking system, which can accurately project a 3D image with low crosstalk into the eyes according to the position of the user's eyes, so that the user can freely move and view within a limited range. In order to reduce 3D crosstalk, an autostereoscopic 3D display usually also has a 3D weaver, which can attenuate the pixels or subpixels that may run into the wrong eye according to the result of the light path simulation, thereby reducing the 3D crosstalk situation of the entire screen.

[0004] Please refer to Figure 1 , which is a schematic diagram of the operation mechanism of an existing autostereoscopic 3D display. Generally, when determining whether a pixel or subpixel corresponds to the left eye or the right eye, the midpoint position of the user's two eyes is usually used as a reference point. In Figure 1 , it is assumed that the autostereoscopic 3D display 100 includes a plurality of pixels 101 (shown as grids) and a 3D lens 102. In addition, it is assumed that Figure 1 the user in

[0005] is facing the autostereoscopic 3D display 100 directly. In this case, after performing eye tracking to obtain the shown midpoint position, the autostereoscopic 3D display 100 can determine which pixels 101 are used to project light rays to the user's right eye and which pixels 101 are used to project light rays to the user's left eye. For example, the pixels 101 shown as dotted grids can be determined to be used to project light rays to the user's left eye, and the pixels 101 shown as slanted grids can be determined to be used to project light rays to the user's left eye. However, when the user turns his head, using the midpoint position of the user's two eyes as a reference point may not be accurate. In this case, the effect of reducing 3D crosstalk may be slightly discounted. Summary of the Invention

[0006] In view of this, the present invention provides a method for reducing 3D crosstalk and a 3D display, which can be used to solve the above technical problems.

[0007] The present invention provides a method for reducing 3D crosstalk, suitable for a 3D display, including: detecting a first eye position and a second eye position of a user, and determining a viewing angle of the user and a rotation angle of the user's head accordingly; estimating a first reference position and a first midpoint position between the first eye and the second eye of the user based on the first eye position and the second eye position of the user; obtaining a second reference position, and estimating a difference amount between the first reference position and the second reference position; correcting the first midpoint position to a second midpoint position based on the rotation angle and the difference amount of the user; and determining at least one first pixel for projecting to the first eye of the user and at least one second pixel for projecting to the second eye of the user among a plurality of pixels of the 3D display based on the second midpoint position.

[0008] The present invention provides a 3D display, including an eye tracking component and a processor. The eye tracking component detects a first eye position and a second eye position of a user. The processor is configured to: determine a viewing angle of the user and a rotation angle of the user's head according to the first eye position and the second eye position; estimate a first reference position and a first midpoint position between the first eye and the second eye of the user based on the first eye position and the second eye position of the user; obtain a second reference position, and estimate a difference amount between the first reference position and the second reference position; correct the first midpoint position to a second midpoint position based on the rotation angle and the difference amount of the user; and determine at least one first pixel for projecting to the first eye of the user and at least one second pixel for projecting to the second eye of the user among a plurality of pixels of the 3D display based on the second midpoint position. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present invention and, together with the description, are used to explain the principles of the present invention.

[0010] Figure 1 is a schematic diagram of the operating mechanism of an existing 3D weaver.

[0011] Figure 2 is a schematic diagram of 3D crosstalk shown according to an embodiment of the present invention.

[0012] Figure 3 is a schematic diagram of a 3D display shown according to an embodiment of the present invention.

[0013] Figure 4 is a flowchart of a method for reducing 3D crosstalk shown according to an embodiment of the present invention.

[0014] Figure 5AIt is a schematic diagram of the scenario of rotating the head around the first eye according to an embodiment of the present invention.

[0015] Figure 5B It is a schematic diagram of the scenario of rotating the head around the second eye according to an embodiment of the present invention.

[0016] Figure 6 It is a corresponding relationship diagram of viewing angle and crosstalk according to an embodiment of the present invention.

[0017] Figure 7 It is a large viewing angle scenario diagram according to an embodiment of the present invention. Detailed implementation manners

[0018] Now, reference will be made in detail to the exemplary embodiments of the present invention. Examples of the exemplary embodiments are illustrated in the accompanying drawings. Whenever possible, the same component symbols are used in the drawings and the description to represent the same or similar parts.

[0019] Please refer to Figure 2 , which is a schematic diagram of 3D crosstalk shown according to an embodiment of the present invention. In Figure 2 , when the user's head rotates, if the midpoint position between the user's two eyes (hereinafter referred to as the first midpoint position X mid ) is still used to determine which pixels should project light to which eye, other 3D crosstalk situations may occur.

[0020] Taking Figure 2 as an example, if the first midpoint position X mid is used as a reference point, the optical path R 1 that should originally be projected into the right eye may be misclassified as corresponding to the left eye because it is less than the reference point. In this case, the left eye will receive the light corresponding to the optical path R 1 and feel 3D crosstalk, which may affect the user's viewing experience.

[0021] However, if the first midpoint position X mid can be corrected to the second midpoint position X mod through a certain mechanism, the optical path R 1 should be correctly assigned to the right eye, thereby improving the above 3D crosstalk situation.

[0022] In view of this, the present invention proposes a method for reducing 3D crosstalk, which can be used to improve the above technical problems.

[0023] Please refer to Figure 3, which is a schematic diagram of a 3D display shown according to an embodiment of the present invention. In an embodiment of the present invention, the 3D display 300 is, for example, a naked-eye 3D display. That is, when a user stands in front of the 3D display 300, the user can directly view the display content with 3D effects on the 3D display 300 by visual means.

[0024] As Figure 3 shown, the 3D display 300 may include an eye tracking component 302 and a processor 304. In some embodiments, the eye tracking component 302 may perform eye tracking on a user located in front of the 3D display 300 to obtain the positions of the user's two eyes in three-dimensional space. For ease of explanation, the positions of the user's two eyes will be abbreviated as the first eye position and the second eye position hereinafter.

[0025] In some embodiments, the 3D display 300 may, for example, have components such as pixels, 3D lenses, 3D weavers, etc. corresponding to the left and right eyes mentioned above, but is not limited thereto.

[0026] The processor 304 is coupled to the eye tracking component 302 and may be a general-purpose processor, a special-purpose processor, a traditional processor, a digital signal processor, multiple microprocessors, one or more microprocessors combined with digital signal processor cores, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array circuit (FPGA), any other type of integrated circuit, a state machine, a processor based on an advanced reduced instruction set machine (ARM), and the like.

[0027] In an embodiment of the present invention, the processor 304 may access specific modules and program codes to implement the method for reducing 3D crosstalk proposed by the present invention, and the details are described in detail below.

[0028] Please refer to Figure 4 , which is a flowchart of the method for reducing 3D crosstalk shown according to an embodiment of the present invention. The method of this embodiment may be executed by the Figure 3 3D display 300, and the details of each step will be described below in conjunction with the Figure 3 components shown. Figure 4 Details of each step.

[0029] First, in step S410, the eye tracking component 302 detects the first eye position and the second eye position of the user. In one embodiment, the x-axis coordinate and the z-axis coordinate of the first eye position (for example, the left eye position) may be respectively represented as x L , and zL The x-axis coordinate and the z-axis coordinate of the second eye position (e.g., the right eye position) can be respectively characterized as x R and z R .

[0030] Next, in step S420, the processor 304 determines the viewing angle δ of the user and the rotation angle θ of the user's head based on the first eye position and the second eye position. In one embodiment, the rotation angle θ can be obtained, for example, based on the formula "θ = tan -1 [(z R - z L ) / (x R - x L )]". In addition, the viewing angle δ can be obtained, for example, based on the formula "δ = 90° - θ".

[0031] In an embodiment of the present invention, when the user faces the 3D display 300 directly, the rotation angle θ of the user's head can be set to 0 degrees, for example, and the viewing angle δ can be estimated to be 90 degrees accordingly.

[0032] After that, in step S430, the processor 304 estimates the first reference position Z δ and the first midpoint position X mid between the user's first eye (e.g., the left eye) and the second eye (e.g., the right eye).

[0033] In one embodiment, the processor 304 can optionally select a point between the z-axis coordinate of the first eye position and the z-axis coordinate of the second eye position as the first reference position Z δ . In one embodiment, the processor 304 can obtain the first reference position Z δ based on the formula "Z R = (z L + z δ ) / 2", but it is not limited thereto.

[0034] In addition, the processor 304 can optionally select a point between the x-axis coordinate of the first eye position and the x-axis coordinate of the second eye position as the first midpoint position X mid . In one embodiment, the processor 304 can obtain the first midpoint position X mid based on the formula "X R = (x L + x mid ) / 2", but it is not limited thereto.

[0035] In step S440, the processor 304 obtains the second reference position Z 90 , and estimates the difference amount Z δ between the first reference position Z 90 and the second reference position Zdiff 。In one embodiment, during the process of obtaining the second reference position Z 90 , the processor 304 may first determine whether the viewing angle δ meets a preset condition. If so, the processor 304 may set the second reference position Z 90 as the first reference position Z δ ; if not, the processor 304 may obtain the first historical reference position corresponding to the time when the user's viewing angle last met the preset condition, and use the first historical reference position as the second reference position.

[0036] In one embodiment, during the process of determining whether the viewing angle δ meets the preset condition, the processor 304 may, for example, determine whether the viewing angle δ is equal to 90 degrees. If so, the processor 304 may determine that the viewing angle δ meets the preset condition, and vice versa, but it is not limited thereto. That is, the processor 304 may determine whether the user is facing the 3D display 300 directly. If so, it may determine that the viewing angle δ meets the preset condition, and then set the second reference position Z 90 as the current first reference position Z δ , and then perform subsequent operations.

[0037] On the other hand, if the processor 304 determines that the viewing angle δ does not meet the preset condition (for example, the user is not facing the 3D display 300 directly), the processor 304 may find the first reference position obtained when the user last faced the 3D display 300 directly as the first historical reference position, and then set the second reference position Z 90 as the first historical reference position.

[0038] In one embodiment, assume that the processor 304 can estimate the corresponding viewing angle δ based on the current first eye position and second eye position at different time points. Assume that at the t-i-th time point, the processor 304 can determine that the current viewing angle (represented by δ t-i ) meets the preset condition based on the current first eye position and second eye position of the user. Then the processor 304 may use the currently obtained first reference position (represented by ) as the second reference position Z 90 . After that, assume that the viewing angle δ t-i+1 obtained at the t-i+1-th time point does not meet the preset condition. Then when the processor 304 executes the step S440 corresponding to the t-i+1-th time point, it may use as the second reference position Z 90 , and then estimate the difference (represented by ) between the current first reference position (represented by ) and the second reference position (i.e., ).

[0039] Assuming that the viewing angles obtained from the t-i+2th time point to the t-1th time point do not satisfy the preset condition, the processor 304 may estimate the corresponding difference amount based on the above teaching.

[0040] Then, assuming that the viewing angle (in terms of δ t ) meets the preset condition again, the processor 304 can obtain the first reference position (in represents) as the second reference position Z 90 Then, assuming that the viewing angle δ obtained at the t+1th time point t+1 If the preset condition is not met, the processor 304 may adopt the following method when executing step S440 corresponding to the t+1th time point: As the second reference position Z 90 , and then estimate the current first reference position (based on ) and the second reference position (ie, ) express).

[0041] In other embodiments, the designer may also set a judgment mechanism for judging whether the viewing angle δ satisfies the preset condition according to the requirements. For example, the processor 304 may also judge that the viewing angle δ satisfies the preset condition when the viewing angle δ falls within a certain range (e.g., between 90-k and 90+k, where k is an arbitrary value), but it is not limited thereto.

[0042] Based on the above teaching, the second reference position Z is obtained. 90 Afterwards, the processor 304 may, for example, based on “Z diff =Z δ -Z 90 "To obtain the difference Z diff , but is not limited to this.

[0043] Then, in step S450, the processor 304 calculates the rotation angle θ and the difference Z of the user. diff Set the first midpoint position X mid Corrected to the second midpoint position X mod In one embodiment, the processor 304 may, for example, mod =X mid +Z aiff ×tan(θ / 2)” to obtain the second midpoint position X mod , but is not limited to this.

[0044] In step S460, the processor 304 calculates the second midpoint position X based on the second midpoint position X. modAmong the multiple pixels of the 3D display 300, at least one first pixel for projecting to the user's first eye (e.g., the left eye) and at least one second pixel for projecting to the user's second eye (e.g., the right eye) are determined.

[0045] In one embodiment, different from the prior art method of regarding the first midpoint position X mid as a reference point, the processor 304 can instead regard the second midpoint position X mod as a reference point, and based on this, determine which pixels in the 3D display 300 (i.e., the first pixels) should project light to the user's first eye and which pixels (i.e., the second pixels) should project light to the user's second eye.

[0046] Thereby, as Figure 2 shown, the optical path R that was originally misplanned to project light to the left eye 1 can be correctly planned to project light to the right eye after the processor 304 changes to use the second midpoint position X mod as a reference point. Thereby, the 3D crosstalk situation felt by the user can be correspondingly alleviated, thus improving the user's experience of viewing the 3D display 300.

[0047] In addition, the general user's habit of rotating the head can be roughly divided into rotating the head around the first eye as the axis and rotating the head around the second eye as the axis. Regarding the displacement amounts of the left and right eyes relative to Z 90 , it can be estimated that when the user turns the head, the axis of rotation is closer to the left eye or the right eye. The eye with the smaller z displacement amount is regarded as the axis of rotation. The z displacement of the right eye is Z diff，R = z R - z R，90 , and the z displacement of the left eye is Z diff，L = z L - z L，90 , if |z diff，R | < |z diff，L |, then the axis of rotation is the right eye, and vice versa, the axis of rotation is the left eye. The method of the present invention can be applied to these two situations. To make the above concepts easier to understand, the following is further illustrated with Figure 5A and Figure 5B for explanation.

[0048] Please refer to Figure 5A , which is a schematic diagram of the situation of rotating the head around the first eye according to an embodiment of the present invention. In Figure 5A , when the user rotates his head clockwise by a rotation angle θ around the first eye E1 (e.g., the left eye), the relationship between the second midpoint position X mod and the first midpoint position X mid can be characterized as "X mod = X mid + Z diffThe relationship of "×tan(θ / 2)"

[0049] Please refer to again Figure 5B , which is a schematic diagram of the scenario of rotating the head around the second eye according to an embodiment of the present invention. In Figure 5B , when the user rotates their head counterclockwise by an angle θ around the second eye E2 (for example, the right eye), the second midpoint position X mod and the first midpoint position X mid The relationship between them can also be characterized by the formula "X mod = X mid + Z diff ×tan(θ / 2)".

[0050] Please refer to Figure 6 , which is a corresponding relationship diagram of viewing angle and crosstalk shown according to an embodiment of the present invention. As Figure 6 shown, when the viewing angle δ is 90 degrees, the degree of crosstalk felt by the user will be the lowest. When the viewing angle δ gradually increases / decreases from 90 degrees, the degree of crosstalk felt by the user will increase accordingly.

[0051] In an embodiment of the present invention, although the situation of 3D crosstalk can be mitigated by the method introduced in the previous embodiment, when the viewing angle δ is too large, it is still difficult to avoid some pixels mis-projecting light onto the wrong eye.

[0052] Please refer to Figure 7 , which is a large viewing angle scenario diagram shown according to an embodiment of the present invention. In Figure 7 the scenario, assume that pixel R k is planned to project light to the user's right eye, but due to the user's large viewing angle δ, the light emitted by pixel R k may be affected by the structure of the 3D lens 102 and cause unnecessary refraction. In this case, the light emitted by pixel R k will possibly enter the user's left eye by mistake, thereby causing the situation of 3D crosstalk.

[0053] For this situation, the present invention further proposes a corresponding processing mechanism, which can attenuate the light projected by the above-mentioned part of the pixels, so as to mitigate 3D crosstalk.

[0054] In an embodiment, the processor 304 can find at least one potential error pixel in the above-mentioned first pixel (corresponding to the first eye) according to the position of the user's first eye and the second eye. In an embodiment of the present invention, the above-mentioned potential error pixel is, for example, a pixel like pixel R k that may project light to the wrong eye.

[0055] Generally speaking, during the manufacturing process of the 3D display 300, it can be known through simulation which pixels of the 3D display 300 will project light and the corresponding light projection angles when the user is at a certain position in front of the 3D display 300, and the relative positions between the light projected by each pixel and the 3D lens 102 can be known in advance. In other words, when the positions of the user's two eyes are known, it can be known in advance which pixels will project light at what angles to which eye through simulation.

[0056] Therefore, which pixels may exhibit the situation such as Figure 7 the pixel R shown k can also be correspondingly deduced after knowing the positions of the user's two eyes. Based on this, after obtaining the positions of the user's two eyes, the processor 304 can regard the pixels that may exhibit the situation such as Figure 7 the pixel R shown k as the above-mentioned potential error pixels.

[0057] After that, the processor 304 can obtain the angular difference between the user's viewing angle δ and the reference angle, and determine the attenuation coefficient based on this. The attenuation coefficient can be negatively correlated with the above-mentioned angular difference (that is, the larger the angular difference, the smaller the attenuation coefficient, and vice versa). After that, the processor 304 can reduce the projected light intensity of each potential error pixel based on this attenuation coefficient. In one embodiment, the attenuation coefficient is, for example, a value less than 1, and the processor 304 can multiply the projected light intensity of each potential error pixel by this attenuation coefficient to reduce the projected light intensity corresponding to each potential error pixel.

[0058] In one embodiment, the above-mentioned reference angle can be set to 90 degrees (that is, the viewing angle with the lowest crosstalk level), for example. In this case, the processor 304 can obtain the angular difference between the viewing angle δ and 90, for example. As Figure 6 shown, the larger the angular difference, the more serious the current crosstalk situation represents. Therefore, the processor 304 can select a smaller attenuation coefficient to more significantly reduce the projected light intensity of each potential error pixel.

[0059] Since the projected light intensity of each potential error pixel has been reduced through the above mechanism, even if the light projected by each potential error pixel enters the wrong eye, it will not cause too much interference to this eye. Thereby, the user experience of viewing the 3D display can be correspondingly improved.

[0060] In summary, after the first midpoint position is corrected to the second midpoint position based on the rotation angle of the user's head and the difference between the first and second reference positions in the embodiments of the present invention, the second midpoint position is used as a reference point to determine which pixels in the 3D display should project light to the user's left eye and which pixels should project light to the user's right eye. Compared with the existing method of using the first midpoint position as a reference point, the embodiments of the present invention can correspondingly reduce the situation of 3D crosstalk, thereby improving the user's experience of viewing the 3D display.

[0061] In addition, when the user's viewing angle is too large and some pixels inevitably project light to the wrong eye, the embodiments of the present invention can reduce the projection light intensity of these pixels, thereby reducing the interference caused by these pixels to the user.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for reducing 3D crosstalk, suitable for a 3D display, characterized in that, comprising: detecting a first eye position and a second eye position of a user, and determining the viewing angle of the user and the rotation angle of the user's head accordingly; estimating a first reference position and a first midpoint position between the user's first eye and second eye based on the user's first eye position and second eye position; obtaining a second reference position and estimating the difference amount between the first reference position and the second reference position; correcting the first midpoint position to a second midpoint position based on the user's rotation angle and the difference amount; and determining at least one first pixel for projecting to the user's first eye and at least one second pixel for projecting to the user's second eye among a plurality of pixels of the 3D display based on the second midpoint position, wherein the step of obtaining the second reference position includes: responding to determining that the viewing angle of the user satisfies a preset condition, setting the second reference position as the first reference position; and responding to determining that the viewing angle of the user does not satisfy the preset condition, obtaining a first historical reference position corresponding to when the viewing angle of the user last satisfied the preset condition, and using the first historical reference position as the second reference position.

2. The method according to claim 1, wherein it is determined that the viewing angle of the user satisfies the preset condition in response to determining that the viewing angle of the user is 90 degrees.

3. The method according to claim 1, wherein the x-axis coordinate and the z-axis coordinate of the first eye position are respectively represented as xL and z L , the x-axis coordinate and the z-axis coordinate of the second eye position are respectively represented as x R and z R , and the rotation angle of the head of the user is represented as θ, where θ = tan -1 [(z R - z L ) / (x R - x L )].

4. The method according to claim 1, wherein the rotation angle of the user's head is characterized as θ, the viewing angle of the user is characterized as δ, and δ = 90° - θ.

5. The method according to claim 1, wherein the x-axis coordinate and the z-axis coordinate of the first eye position are respectively represented as x L and z L , the x-axis coordinate and the z-axis coordinate of the second eye position are respectively represented as x R and z R , the first midpoint position is represented as X mid , where X mid = (x R + x L ) / 2.

6. The method according to claim 1, wherein the first midpoint position is characterized as X mid , the amount of difference is characterized as Z diff , the second midpoint position is characterized as X mod , the rotation angle of the head of the user is characterized as θ, and X mod = X mid + Z diff × tan(θ / 2).

7. The method according to claim 1, wherein the z-axis coordinate of the first eye position is characterized as z L , the z-axis coordinate of the second eye position is characterized as z R , the first reference position is characterized as Z δ , and Z δ = (z R + z L ) / 2.

8. The method according to claim 1, wherein after the step of determining at least one first pixel for projecting to the user's first eye and at least one second pixel for projecting to the user's second eye among a plurality of pixels of the 3D display based on the second midpoint position, further comprising: finding at least one potential error pixel among the at least one first pixel according to the user's first eye position and second eye position; obtaining the angle difference between the user's viewing angle and a reference angle, and determining an attenuation coefficient accordingly, wherein the attenuation coefficient is negatively correlated with the angle difference; reducing the projection light intensity of each potential error pixel based on the attenuation coefficient.

9. A 3D display, characterized in that, comprising: an eye tracking component that detects a first eye position and a second eye position of a user; a processor configured to: determine the viewing angle of the user and the rotation angle of the user's head according to the first eye position and the second eye position; estimate a first reference position and a first midpoint position between the user's first eye and second eye based on the user's first eye position and second eye position; If it is determined that the user's perspective meets a preset condition, set the second reference position as the first reference position. If it is determined that the user's perspective does not meet the preset condition, obtain the first historical reference position corresponding to when the user's perspective last met the preset condition, and use the first historical reference position as the second reference position; Estimate the difference amount between the first reference position and the second reference position; Based on the user's rotation angle and the difference amount, correct the first midpoint position to a second midpoint position; and Based on the second midpoint position, determine at least one first pixel for projecting to the user's first eye and at least one second pixel for projecting to the user's second eye among the multiple pixels of the 3D display.

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