Stereoscopic camera device

Abstract

A stereoscopic camera device adapted to signally connect to a stereoscopic display to display a stereoscopic image on the stereoscopic display. The stereoscopic camera device includes a first camera, a second camera and a processor. The first camera is configured to shoot towards an object to obtain a first image of the object. The second camera is configured to shoot towards the object to obtain a second image of the object. The processor is electrically connected to the first camera and the second camera. The processor crops the first image and the second image or scales the first image and the second image according to a specification of the stereoscopic display to output a processed first image and a processed second image so that a size of a part corresponding to the object in the stereoscopic image displayed on the stereoscopic display is in a specific proportion to a size of the object.

Description

[Technical Field]

[0001] The present invention relates to a photographic apparatus, and more particularly to a stereoscopic photographic apparatus. [Previous Technology]

[0002] Generally, a monitor passively receives images from a signal source and displays them directly on the monitor by scaling them according to the monitor's resolution. However, there is a real application need in the display field for objects in images displayed on a monitor to have a specific ratio to the objects themselves, such as a 1:1 ratio.

[0003] In order to achieve the aforementioned specific aspect ratio, the photographic device needs to use a wide-angle or telephoto lens to narrow the field of view during shooting. However, when applied to a stereoscopic display, the size of the image on the display changes with the user's viewing distance. Therefore, there is a difficulty in selecting the lens focal length or field of view when shooting stereoscopic images. [Summary of the Invention]

[0004] The present invention provides a stereoscopic photography device that enables the size of the corresponding object portion in a stereoscopic image displayed on a stereoscopic display screen to be in a specific ratio to the size of the object.

[0005] An embodiment of the present invention provides a stereoscopic photography apparatus suitable for signal connection to a stereoscopic display to display stereoscopic images on the stereoscopic display. The stereoscopic photography apparatus includes a first camera, a second camera, and a processor. The first camera is used to photograph an object to obtain a first image of the object. The second camera is used to photograph the object to obtain a second image of the object. The processor is electrically connected to the first camera and the second camera. The processor crops or scales the first image and the second image according to the specifications of the stereoscopic display to output processed first and second images, such that the size of the portion corresponding to the object in the stereoscopic image displayed on the stereoscopic display is in a specific ratio to the size of the object.

[0006] Based on the above, in one embodiment of the present invention, the stereoscopic photography device includes a first camera, a second camera, and a processor. The processor can crop or scale the first and second images according to the specifications of the stereoscopic display to output processed first and second images, such that the size of the corresponding object portion in the stereoscopic image displayed on the stereoscopic display is in a specific ratio to the size of the object. Therefore, the stereoscopic photography device of this embodiment can easily make the stereoscopic image displayed on the stereoscopic display in a specific ratio.

Implementation Method

[0007] FIG1 is a schematic diagram of a stereoscopic photography apparatus according to an embodiment of the present invention. FIG2 is a schematic diagram of cropping or scaling a first image and a second image using a stereoscopic photography apparatus according to an embodiment of the present invention.

[0008] Referring to Figures 1 and 2, an embodiment of the present invention provides a stereoscopic imaging device 10 suitable for signal connection to a stereoscopic display to display stereoscopic images on the stereoscopic display. The stereoscopic imaging device 10 includes a first camera 100, a second camera 200, and a processor 300. The first camera 100 is used to photograph an object O to obtain a first image I1 of the object O. The second camera 200 is used to photograph the object O to obtain a second image I2 of the object O. The processor 300 is electrically connected to the first camera 100 and the second camera 200. The processor 300, according to the specifications of the stereoscopic display, crops or scales the first image I1 and the second image I2 to output processed first images ZCI1 and second images ZCI2, such that the size of the portion corresponding to the object O in the stereoscopic image displayed on the stereoscopic display is in a specific ratio to the size of the object O. The specific ratio is, for example, 1:1, but the present invention is not limited thereto.

[0009] In detail, the first camera 100 and the second camera 200 may be complementary metal-oxide-semiconductor (CMOS) cameras or charge-coupled device (CCD) cameras, but the present invention is not limited thereto.

[0010] In this embodiment, the processor 300 may include, for example, a microcontroller unit (MCU), a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a programmable controller, a programmable logic device (PLD), or other similar devices or combinations thereof, and the present invention is not limited thereto. Furthermore, in one embodiment, the functions of the processor 300 may be implemented as multiple code snippets. These code snippets are stored in a memory and executed by the processor 300. Alternatively, in one embodiment, the functions of the processor 300 may be implemented as one or more circuits. The present invention does not limit the implementation of the functions of the processor 300 in software or hardware.

[0011] In Figure 1, the first camera 100 and the second camera 200 are shooting at object O, and the optical axis A1 of the first camera 100 and the optical axis A2 of the second camera 200 have toe-in angles θ1 and θ2, respectively. The intersection point (i.e., the focus point) P2 of the optical axis A1 of the first camera 100 and the optical axis A2 of the second camera 200 defines the display surface DP of the stereoscopic display. The straight line formed between the first camera 100 and the second camera 200 is the baseline B, and the display surface DP is parallel to the baseline B.

[0012] When the position P1 of object O is behind the display surface DP (the display surface DP is located between position P1 and baseline B), the stereoscopic image displayed on the stereoscopic display has the effect of being sunk inside the stereoscopic display. Conversely, when the position P1 of object O is in front of the display surface DP (position P1 is located between the display surface DP and baseline B), the stereoscopic image displayed on the stereoscopic display has the effect of floating out of the stereoscopic display.

[0013] In Figure 2, the image position of object O captured by the first camera 100 falls at position L of the first image I1, and the image position of object O captured by the second camera 200 falls at position R of the second image I2. The upper part of Figure 2 illustrates the image synthesized / superimposed from the first image I1 and the second image I2, and the image synthesized / superimposed from the cropped first image CI1 and the cropped second image CI2. The lower part of Figure 2 illustrates the image synthesized / superimposed from the cropped and scaled first image (i.e., the processed first image) ZCI1 and the cropped and scaled second image (i.e., the processed second image) ZCI2. Furthermore, when the first image I1 and the second image I2 are cropped, the image content within the cropped area is retained, and the content outside the cropped area is deleted, resulting in cropped first images CI1 and second images CI2.

[0014] In this embodiment, the cropping rates of the processed first image ZCI1 and second image ZCI2 relative to the first image I1 and second image I2 satisfy the following formula (1): , , (1) where t y1 is the cropping rate in the vertical direction D1, t x1 is the cropping rate in the horizontal direction D2, VD is the viewing distance of the stereoscopic display, VFoV is the field of view of the first camera 100 and the second camera 200 in the vertical direction D1, HFoV is the field of view of the first camera 100 and the second camera 200 in the horizontal direction D2, PSD is the size of each pixel of the stereoscopic display (generally, the size of the pixel in the horizontal and vertical directions is equal), VRD is the number of pixels of the stereoscopic display in the vertical direction D1, and HRD is the number of pixels of the stereoscopic display in the horizontal direction D2.

[0015] In this embodiment, the cropping rates of the processed first image ZCI1 and second image ZCI2 relative to the first image I1 and second image I2 satisfy the following formulas (2) and (3): , , (2) , , (3) where t y2 is the scaling rate in the vertical direction D1, t x2 is the scaling rate in the horizontal direction D2, y1 is the size of the first image I1 and second image I2 in the vertical direction D1, x1 is the size of the first image I1 and second image I2 in the horizontal direction D2, y2 is the size of the cropped first image I1 and second image I2 in the vertical direction D1, x2 is the size of the cropped first image CI1 and second image CI2 in the horizontal direction D2, y3 is the size of the cropped and scaled first image ZCI1 and second image ZCI2 in the vertical direction D1, and x3 is the size of the cropped and scaled first image I1 and second image I2 in the horizontal direction D2.

[0016] Taking a 15.6-inch, 4K resolution stereoscopic display as an example, the width of the display surface DP of the stereoscopic display can be 344.2176 mm, and the number of pixels HRD in the horizontal direction D2 of the stereoscopic display can be 3840. Therefore, the size PSD of each pixel of the stereoscopic display can be 344.2176 / 3840 = 0.08964 mm / pixel. Furthermore, the field of view VFoV of the stereoscopic display in the vertical direction D1 can be 60.1 degrees, and the number of pixels VRD in the vertical direction D1 of the stereoscopic display can be 2160. Considering that the viewing distance VD is 600 mm, the cropping rate ty1 in the vertical direction D1 can be obtained from the above formula (1) as 3.585.

[0017] Furthermore, in this embodiment, the cropped first image CI1 and second image CI2 satisfy the following equation (4): (4) where d1 is the parallax between the first image CI1 and the second image CI2, and d2 is the parallax between the cropped first image CI1 and the second image CI2. Wherein, when the parallax is 0, the position of the stereoscopic image falls on the display surface DP of the stereoscopic display. When the parallax is positive, the stereoscopic image has the effect of being submerged within the stereoscopic display. Conversely, when the parallax is negative, the stereoscopic image has the effect of floating out of the stereoscopic display.

[0018] In this embodiment, the processed first image ZCI1 and second image ZCI2 satisfy the following formula (5): , (5) where d3 is the parallax between the processed first image ZCI1 and second image ZCI2 (or the parallax of the cropped and scaled first image ZCI1 and second image ZCI2 in the horizontal direction D2).

[0019] Figure 3 is a schematic diagram of the human eye viewing a stereoscopic display. Figure 4 is a schematic diagram of the vergence-accommodation conflict (VAC) when the human eye views a stereoscopic display. In Figure 3, the intersection of the viewer's left eye LE and right eye RE lines of sight falls on the display surface DP, where the interpupillary distance between the left eye LE and the right eye RE is IPD. Consider the difference VAC between human eye accommodation and convergence as shown in the following equation (6): , (6) where DIS is the disparity. When the difference VAC falls within ±0.5 degrees, it can reduce the viewer's discomfort when viewing stereoscopic images.

[0020] Figure 4 is a graph of the parallax of a 15.6-inch stereoscopic display at various viewing distances VD under a difference of VAC ±0.5 degrees. In Figure 4, when the viewing distance VD is 600 mm, the condition that the above VAC falls within the range of ±0.5 degrees corresponds to a parallax range of ±10.48788 mm or ±117 pixels (since PSD is 0.08964 mm / pixel). That is, Figure 2 shows that the parallax d3 between the processed first image ZCI1 and the second image ZCI2 is greater than the parallax d1 between the first image I1 and the second image I2 (but the present invention is not limited to this). However, when the parallax d3 does not satisfy -117 pixels ≤ d3 ≤ +117 pixels (i.e., the following formula (10)), the system preferably reduces the parallax to reduce the discomfort of the viewer when viewing the stereoscopic image.

[0021] FIG5A is a schematic diagram of a stereoscopic photography apparatus according to an embodiment of the present invention, showing the offset and cropping of a first image and a second image. FIG5B is a schematic diagram of the composite / overlay of the offset and cropped first image and second image in FIG5A.

[0022] Please refer to Figures 3 to 5B. In this embodiment, when the absolute value of d3 is greater than the comfortable parallax value, the processor 300 offsets the cropping ranges CR1 and CR2 of the first image I1 and the second image I2 along the horizontal direction D2 (to form cropping ranges CR1' and CR2') according to the cropping offset value, so as to obtain the offset cropped first image CI1' and second image CI2'. The processor 300 then scales the offset cropped first image CI1' and second image CI2' according to the scaling ratios ty2 and tx2 to generate the processed first image and second image. Among them, the lower part of Figure 5B shows the image synthesized / superimposed by the offset cropped first image CI1' and second image CI2'. Compared with the image synthesized / superimposed by the first image I1 and the second image I2 in the upper part of Figure 5B, the absolute value of the parallax d'1 (i.e., the difference between positions L' and R') in the image below Figure 5B is smaller than the absolute value of the parallax d1 in the image above Figure 5B.

[0023] In this embodiment, the offset direction of the cropping range of the first image I1 is opposite to the offset direction of the cropping range of the second image I2 (as shown in equation (12) below).

[0024] In this embodiment, based on the relative relationships between the distances dL1, d'L1, dR1, and d'R1 in Figure 5A, the following equations (7) and (8) can be obtained: (7), (8) where SL and SR are the cropping offset values ​​of the first image I1 and the second image I2, respectively. Moreover, in Figure 5A, SR > 0 and SL < 0.

[0025] In this embodiment, according to the following equations (9) and (10), the following equation (11) can be obtained: , (9), (10), (11) where CD is the comfort parallax value (e.g., ±117 pixels in Figure 4 above). Considering the following equation (12), the cropping offset value satisfies the following equation (13): , (12), (13) where S is the cropping offset value.

[0026] That is to say, Figure 2 above illustrates that the parallax d3 of the first image I1 and the second image I2 after cropping and scaling is greater than the parallax d1 of the original first image I1 and the second image I2. When the parallax d3 satisfies the above formula (10), the stereoscopic imaging device 10 can directly output the cropped and scaled first image ZCI1 and the cropped and scaled second image ZCI2. Conversely, when the parallax d3 does not satisfy the above formula (10), the stereoscopic imaging device 10 can generate the processed first image and second image by offset cropping and scaling the first image and the second image as shown in Figures 5A and 5B. Therefore, the stereoscopic imaging device 10 can reduce the discomfort of viewers when viewing stereoscopic images.

[0027] Figure 6 is a schematic diagram of the relationship between parameters such as baseline, distance between object and baseline, focal length of first camera and second camera in a stereoscopic photography apparatus according to another embodiment of the present invention.

[0028] Referring to Figure 6, in this embodiment, when the absolute value of d3 is greater than the comfort parallax value CD, the processor 300 adjusts the length BL of the baseline B between the first camera 100 and the second camera 200 to reduce the parallax between the first image I1 and the second image I2. For example, the stereoscopic imaging device also includes an actuator, which is connected to the first camera 100 and the second camera 200 respectively, and electrically connected to the processor 300. The actuator is used to change the inclination angle θ1 and position C1 of the optical axis A1 of the first camera 100, and to change the inclination angle θ2 and position C2 of the optical axis A2 of the second camera 200.

[0029] In detail, the first camera 100 and the second camera 200 shoot toward position P2. At the first camera 100, object O is imaged at imaging point IP1, and at the second camera 200, object O is imaged at imaging point IP2. Therefore, the parallax of the stereoscopic image satisfies the following equation (14): (14) where, distance x is the distance between imaging point IP1 and the optical axis of the first camera 100, x' is the distance between imaging point IP2 and the optical axis of the second camera 200, f is the focal length of the first camera 100 and the second camera 200 (for example, the first camera 100 and the second camera 200 each include a lens element and an imaging element, and f is the focal length of the lens element), and Z is the distance between object O and baseline B.

[0030] Due to the following formulas (15) to (17): , (15), (16), (17) In this embodiment, the length BL of the baseline B between the first camera 100 and the second camera 200 satisfies the following formula (18): , (18) where mc is the size of each pixel of the first image I1 and the second image I2.

[0031] That is to say, when shooting stereoscopic images, the length BL of the baseline B between the first camera 100 and the second camera 200 is adjusted at the same time so that the absolute value of the parallax d3 is less than the comfort parallax value CD, thereby reducing the discomfort of the viewer when watching stereoscopic images.

[0032] In summary, in one embodiment of the present invention, the stereoscopic photography device includes a first camera, a second camera, and a processor. The first camera is used to photograph an object to obtain a first image of the object. The second camera is used to photograph the object to obtain a second image of the object. The processor crops or scales the first and second images according to the specifications of the stereoscopic display to output processed first and second images, such that the size of the portion corresponding to the object in the stereoscopic image displayed on the stereoscopic display is in a specific ratio to the size of the object. Therefore, the stereoscopic photography device of the present invention can easily make the stereoscopic image displayed on the stereoscopic display in a specific ratio. [Simplified Explanation of the Diagram]

[0033] Figure 1 is a schematic diagram of a stereoscopic photography apparatus according to an embodiment of the present invention. Figure 2 is a schematic diagram of cropping or scaling a first image and a second image using a stereoscopic photography apparatus according to an embodiment of the present invention. Figure 3 is a schematic diagram illustrating human eye viewing a stereoscopic display. Figure 4 is a schematic diagram illustrating the existence of visual vergence-accommodation conflict when human eye views a stereoscopic display. Figure 5A is a schematic diagram of offsetting and cropping a first image and a second image using a stereoscopic photography apparatus according to an embodiment of the present invention. Figure 5B is a schematic diagram of combining / overlaying the first image and the second image after offsetting and cropping in Figure 5A. Figure 6 is a schematic diagram of the relationship between parameters such as the baseline, the distance between the object and the baseline, and the focal lengths of the first camera and the second camera using a stereoscopic photography apparatus according to another embodiment of the present invention.

Claims

1. A stereoscopic imaging apparatus, adapted for signal connection to a stereoscopic display to display a stereoscopic image on the stereoscopic display, the stereoscopic imaging apparatus comprising: A first camera is used to photograph an object to acquire a first image of the object; a second camera is used to photograph the object to acquire a second image of the object; and a processor is electrically connected to the first and second cameras, wherein the processor crops or scales the first and second images according to the specifications of the stereoscopic display to output processed first and second images, such that the size of the portion corresponding to the object in the stereoscopic image displayed on the stereoscopic display is in a specific ratio to the size of the object, wherein the cropping ratio of the processed first and second images relative to the first and second images satisfies: , , Where ty1 is the cropping rate in the vertical direction, tx1 is the cropping rate in the horizontal direction, VD is the viewing distance of the stereoscopic display, VFoV is the field of view of the first camera and the second camera in the vertical direction, HFoV is the field of view of the first camera and the second camera in the horizontal direction, PSD is the size of each pixel of the stereoscopic display, VRD is the number of pixels of the stereoscopic display in the vertical direction, and HRD is the number of pixels of the stereoscopic display in the horizontal direction.

2. The stereoscopic photography apparatus as claimed in claim 1, wherein the scaling factors of the processed first image and the second image relative to the first image and the second image satisfy: , , , where ty2 is the scaling factor in the vertical direction, tx2 is the scaling factor in the horizontal direction, y1 is the size of the first image and the second image in the vertical direction, x1 is the size of the first image and the second image in the horizontal direction, y2 is the size of the cropped first image and the second image in the vertical direction, x2 is the size of the cropped first image and the second image in the horizontal direction, y3 is the size of the cropped and rescaled first image and the second image in the vertical direction, and x3 is the size of the cropped and rescaled first image and the second image in the horizontal direction.

3. The stereoscopic photography apparatus as claimed in claim 2, wherein the processed first image and the second image satisfy: , where d1 is the parallax between the first image and the second image, and d3 is the parallax between the processed first image and the second image.

4. The stereoscopic photography apparatus as claimed in claim 3, wherein when the absolute value of d3 is greater than a comfortable parallax value, the processor offsets the cropping range of the first image and the second image along the horizontal direction according to a cropping offset value to obtain the offset cropped first image and the second image, and the processor then scales the offset cropped first image and the second image according to the scaling factor to generate the processed first image and the second image.

5. The stereoscopic photography apparatus as claimed in claim 4, wherein the offset direction of the cropping area of ​​the first image is opposite to the offset direction of the cropping area of ​​the second image.

6. The stereoscopic photography apparatus as claimed in claim 4, wherein the crop offset value satisfies: , where S is the crop offset value and CD is the comfort parallax value.

7. The stereoscopic photography apparatus of claim 3, wherein when the absolute value of d3 is greater than a comfortable parallax value, the processor adjusts the length of the baseline between the first camera and the second camera to reduce the parallax between the first image and the second image.

8. The stereoscopic photography apparatus of claim 7, wherein the length of the baseline between the first camera and the second camera satisfies: , where BL is the length of the baseline, Z is the distance between the object and the baseline, mc is the size of each pixel of the first image and the second image, f is the focal length of the first camera and the second camera, and CD is the comfort parallax value.

Images