CN114529458A - Method and device for realizing large-range continuous optical zooming based on fixed-focus lens - Google Patents

Method and device for realizing large-range continuous optical zooming based on fixed-focus lens Download PDF

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CN114529458A
CN114529458A CN202210265037.1A CN202210265037A CN114529458A CN 114529458 A CN114529458 A CN 114529458A CN 202210265037 A CN202210265037 A CN 202210265037A CN 114529458 A CN114529458 A CN 114529458A
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王国忠
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Abstract

The invention discloses a method and equipment for realizing large-range continuous optical zooming based on a fixed-focus lens, which relate to the field of optical photography and are characterized in that S1: determining the center coordinate, the radius and the area of a minimum light spot formed by focusing light emitted by a distant object point through a fixed-focus lens; s2: the electric signal of a certain color light generated by any pixel is generated by irradiating the corresponding sub-pixel with the light of the color emitted by the sub-object point of the corresponding object point; s3: any pixel will generate three sets of equations for the pixel sub-pixel electrical signal; s4: solving an electrical signal equation set of a group of pixels to obtain electrical signals of three-color light output by sub-pixels of the group of pixels; s5: the electrical sub-pixel signals of the set of pixels are processed by an image processing program to obtain a picture at magnification m x n. The invention is based on the sensitivity of the photosensitive element and the super strong chip arithmetic capability, so that the mobile phone camera can realize approximate continuous optical zooming in a large range to shoot photos like a long-focus camera.

Description

Method and device for realizing large-range continuous optical zooming based on fixed-focus lens
Technical Field
The invention relates to the field of optical photography, in particular to a large-range optical zooming method and equipment.
Background
Mobile phone photography is becoming one of the most important functions of mobile phones. Due to the limitation of volume, the current mobile phone camera is almost a fixed-focus lens, only can be used for digital zooming, and cannot continuously realize optical zooming in a large range, which is an inherent defect of the mobile phone camera. The digital zoom effect is not comparable to the optical zoom. Recently, although liquid lenses are available, the achievable zoom range is too small, and the imaging quality cannot be guaranteed. Most of cameras of the existing mobile phones use fixed-focus lenses, and optical zooming, especially ultra-wide optical zooming, cannot be realized. The light received by any pixel of the camera photosensitive element comes from a small finite-size object point of the scene, which can be seen as a set of several smaller, non-overlapping sub-object points, and the light emitted by these sub-object points is focused on a pixel and cannot be resolved. The optical signals of the sub-object points are converted into an electric signal of a total pixel during shooting and recorded.
Disclosure of Invention
The invention provides a method and equipment for realizing large-range continuous optical zooming based on a fixed-focus lens, so as to achieve the purpose that the fixed-focus lens of a mobile phone camera can realize large-range approximately continuous optical zooming.
In order to achieve the purpose, the invention provides the following technical scheme:
a method for realizing large-range continuous optical zooming based on a fixed-focus lens,
the method comprises the following steps of taking a picture with an equivalent zooming multiple of mxn by using a lens with a fixed optical zooming multiple of m, wherein the specific method for carrying out simulated zooming processing in the process comprises the following steps:
s1: the object point is regarded as a luminous point light source; in a first coordinate system, the coordinates of the point light source in the first coordinate system are (r, phi, z), wherein z > 0; for any object point, light emitted by the object point is refracted through the lens to form a light cone, the plane of the minimum light spot of the light cone is perpendicular to the central axis of the light cone, and the shape of the minimum light spot is approximately circular;
according to the circular symmetry of the rotation around the optical axis of the lens, the optical axis of the lens is the Z axis of the first coordinate system, and only the set of a large number of object points with fixed phi angles needs to be considered; the plurality of object points have different r and z coordinates; for each object point, the center coordinate and the light spot half of the minimum light spot of a light cone formed by light emitted by the object point after passing through the lens are accurately measuredDiameter; for the data, the minimum spot center coordinate R of a light cone formed by light emitted by any object point after passing through a lens can be obtained by using a data fitting processing methodλ(r,z)、ΦλPhi + pi and Zλ(r, z) and minimum spot radius aλ(r, z), both of which are functions of the coordinates of the object point; in a first coordinate system Zλ(r, z) < 0; the indices λ 1,2,3 represent blue, green and red light, respectively;
when the coordinate z of the object point is > 0, the central coordinate R of the light spotλ(r, Z) and Zλ(r, z) and spot radius aλ(r, z) is substantially no longer affected by z; for light with different colors emitted by the same object point, the coordinates and the sizes of the generated light spots have some differences;
the light rays emitted by the object point are focused to form a light cone after passing through the lens, the outer surface of the light cone near the minimum light spot is approximate to a hyperboloid, and the hyperboloid is formed by rotating the hyperboloid around the central axis of the light cone; assuming that the expression of the hyperbola is
Figure BDA0003552300910000021
The plane represented by v ═ 0 is the first section, namely the plane where the minimum spot of the light cone is located; a plane d away from the first section is a second section of the light cone, and the area of a circular light spot intersected with the second section and the light cone is
Figure BDA0003552300910000022
S2: the photosensitive element of the camera comprises a plurality of pixels, and each pixel is formed by sequentially superposing photosensitive layers for sensing blue light, green light and red light from outside to inside. A photograph is taken at a magnification of m x n, where m is the fixed magnification of the fixed focus lens, and the pixels of the photosensitive elements need to be seen as being composed of n circular sub-pixels of approximately equal area. In the case of focusing, each pixel corresponds to an object point of limited size which irradiates light onto the pixel, and n sub-pixels of each pixel correspond to n sub-object points of the object point. Each pixel senses the light energy emitted by the corresponding object point and converts the light energy into an output electric signal;
s3: each time of shooting, the electric signal of a certain color light output by any pixel is the sum of electric signals generated by the sub-object points corresponding to the object points emitting the light of the color on the corresponding sub-pixels; the distance between the lens and the photosensitive element is changed for shooting n times, and for each color of light, any pixel generates an n-element one-time non-homogeneous linear equation system of the sub-pixel electric signals of the pixel. Three photosensitive layers corresponding to the photosensitive elements and having blue, green and red light, each pixel generating n-element one-time non-homogeneous linear equation set of three sub-pixel electric signals;
s4: solving a set of sub-pixel electrical signal equations for a number of pixels, wherein each pixel generates electrical signals for 3n sub-pixels, where n is the number of sub-pixels per pixel and 3 refers to the three colors blue, green, and red;
s5: the electrical sub-pixel signals of the set of pixels are processed by an image processing program to obtain a picture at magnification m x n.
S3 electric signal generation method for pixels and pixel sub-pixels of the light receiving element:
the light received by any pixel is from an object point with a certain size at a distance, a photosensitive layer which senses different colors of each pixel is considered to be composed of n sub-pixels with approximately equal areas and basically no overlapping, the object point irradiated on the pixel under the focusing condition is also considered to be composed of n sub-object points with approximately equal areas and basically no overlapping, and light cones obtained after the light emitted by the sub-object points of the object point is focused by a lens are in one-to-one correspondence with the sub-pixels of the pixel, so that the area of the pixel is required to be far larger than the area of the minimum light spot of the light cone obtained after the light emitted by a far extremely small point light source is focused by the lens; the electric signal output by any pixel is the linear superposition of n light cone light energies obtained after the light emitted by n sub-object points of the object point with limited size corresponding to the pixel is focused by the lens.
The method for calculating the electric signal generated by the sub-pixel of any one of the pixels of S3 includes:
in the second coordinate system, according to the specific arrangement position of the pixels of the photosensitive elementThe center coordinates of any pixel on the photosensitive element and the polar coordinates of the center of the sub-pixel with n areas approximately equal and not overlapping each other can be obtained
Figure BDA0003552300910000041
α is an index of the tag pixel, i is 1,2, …, and n is the ith sub-pixel of the tag pixel.
Continuously shooting n times by changing the distance between the lens and the photosensitive element, wherein the photosensitive layer plane of the photosensitive element and the XOY plane of the first coordinate system, i.e. the plane perpendicular to the central part of the lens and the optical axis, are parallel to each other and have a distance of Zλ,jThe index λ refers to a photosensitive layer for sensing different colors of light, j is 1,2, …, n marks n different distances; the coordinate Z of the minimum light spot center of the light cone after the light emitted by the neutron object point in the first coordinate system is focused by the lensλ(R, z) < 0, the effective radius of the lens is R, the area of a single pixel of the photosensitive element is Sc(ii) a The cosine of an included angle between the central axis of a light cone with the color of lambda and the vertical Z axis, which corresponds to the ith sub-pixel irradiated on the alpha-th pixel, is as follows:
Figure BDA0003552300910000042
the central point (R) of the light cone of the ith sub-pixel of the alpha pixel is irradiatedλ(r,z),Zλ(r, z)) a distance along the cone axis to the center of the ith sub-pixel:
Figure BDA0003552300910000043
simultaneously, the relation is satisfied:
Figure BDA0003552300910000044
the minimum spot plane color of the light cone illuminating the ith sub-pixel of the alpha pixel is λ:
Figure BDA0003552300910000045
herein Iλ,α,iRefers to the average intensity of light impinging at the minimum spot of the light cone of color λ of the ith sub-pixel of the alpha-th pixel, and δ t refers to the time interval of illumination. Because the light energy impinging on the pixels is converted to light energy in a fixed proportionThe electrical signal output, and therefore the optical energy referred to in this patent, is equivalent to the electrical signal generated. Defining:
Figure BDA0003552300910000046
(ii) a The electrical signal generated in the light sensing time deltat when the light cone with the color of lambda irradiates the ith sub-pixel of the alpha pixel is as follows:
Figure BDA0003552300910000047
here, the
Figure BDA0003552300910000048
Means for varying the distance Z between the plane of the sensitive layer and the lensλ,jMeanwhile, the light irradiated to the ith sub-pixel of the alpha-th pixel is irradiated to the periphery of the pixel, and the light originally irradiated to the periphery of the pixel is irradiated to the ith sub-pixel of the pixel to influence the electric signal. Stipulate at a certain
Figure BDA0003552300910000049
When the camera is in focus, all the cameras are in focus
Figure BDA0003552300910000051
In addition, when the pixel subpixel n is relatively large, the subpixels that are not at the pixel edge are
Figure BDA0003552300910000052
Can also be considered approximately as 1, so only for sub-pixels at the edge of the pixel
Figure BDA0003552300910000053
Requiring specific experimentation or simulation.
The calculation method of the electrical signal equation set of S3 and the generation method of the photo are as follows:
when each pixel of the photosensitive element is considered to be composed of n sub-pixels, that is, when a picture is taken at a magnification of m × n, it is necessary to change the distance Z between the plane of the photosensitive layer of the photosensitive element and the plane of the lensλ,jJ 1,2 …, n, the electrical signal T output by the pixel is recordedλ,j,α(ii) a Output electric signal T of photosensitive layer of any pixel alpha sensing lambda colorλ,j,αEqual to the sum of the sub-pixel output electrical signals of the pixel, i.e.:
Figure BDA0003552300910000054
for any pixel alpha, when lambda is 1, namely corresponding to the blue photosensitive layer, j is taken from 1 to n, namely the distance Z between the photosensitive layer and the lens plane is changedλ,jAnd shooting for n times to obtain n similar equations, wherein the n equations jointly form an n-order linear non-homogeneous equation set of the sub-pixel blue light electric signal of the pixel. And when the value of the lambda is 2 and 3, obtaining an n-order linear non-homogeneous equation set of the green light electric signals and the red light electric signals of the sub-pixels of the pixel. The equations for these three lights are obtained simultaneously n shots, and each pixel produces three such electrical signal equations. Solving the system of equations for the sub-pixel electrical signals for N pixels (numbered 1,2 …, N) to obtain N sets of electrical signals:
Figure BDA0003552300910000055
the set of data comprises 3nN Qλ,α,iFrom these 3nN Qλ,α,iAfter the treatment, a photograph with a magnification of m × n was obtained. The N pixels are typically selected at the center of the photosensitive element, and the specific number of pixels is determined by how many times the picture is taken and the pixels of the picture, i.e., the total pixels of the picture equals nN.
An apparatus for realizing a large-range continuous optical zoom based on a fixed focus lens, comprising: the device comprises a lens, a photosensitive element, a moving assembly, a controller and an information processing device; the photosensitive element comprises three layers of stacked photosensitive materials which sequentially sense blue light, green light and red light; the main optical axis of the lens penetrates through the center of the photosensitive side of the photosensitive element; the moving assembly is clamped with the edge of the lens; the moving assembly is electrically connected with the controller; the photosensitive element is electrically connected with the information processing device.
Because the invention depends on the sensitivity of the photosensitive element of the camera and the super strong chip arithmetic capability, the following beneficial effects can be obtained:
compared with the prior art, the invention provides a method and equipment for realizing large-range continuous optical zooming based on a fixed-focus lens, wherein the method comprises the following steps:
the approximately continuous large-range optical zooming of the mobile phone camera can be realized;
the phase field bending distortion of the mobile phone lens can be well eliminated;
and thirdly, on the basis of the sensitivity of the photosensitive element and the super-strong chip computing capability, the fixed-focus lens of the mobile phone camera can realize large-range approximately continuous optical zooming, the camera of the mobile phone can take pictures like a long-focus camera, and the inherent problem that the conventional mobile phone cannot realize optical zooming, particularly large optical zooming, is solved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention is described in further detail below with reference to the attached drawings, and it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 shows a first coordinate system and an object point light cone of the present invention.
Fig. 2 shows a schematic diagram of the invention at the minimum spot of the object point light cone.
FIG. 3 is a schematic diagram of a first coordinate axis and a second coordinate axis according to the present invention.
Fig. 4 shows a single pixel sub-pixel schematic of the present invention.
In the figure: 1-object point, 2-minimum spot, 3-minimum spot center, 4-pixel.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1: the method comprises the following steps of taking a picture with an equivalent zooming multiple of mxn by using a lens with a fixed optical zooming multiple of m, wherein the specific method for carrying out simulated zooming processing in the process comprises the following steps:
s1: regarding the object point 1 as a light-emitting point light source; in a first coordinate system, the coordinates of the point light source in the first coordinate system are (r, phi, z), wherein z > 0; for any object point, light emitted by the object point is refracted through the lens to form a light cone, the plane of the minimum light spot 2 of the light cone is perpendicular to the central axis of the light cone, and the shape of the minimum light spot is approximately circular;
according to the circular symmetry of the rotation around the optical axis of the lens, the optical axis of the lens is the Z axis of the first coordinate system, and only the set of a large number of object points with fixed phi angles needs to be considered; the plurality of object points have different r and z coordinates; for each object point, accurately measuring the central coordinate and the light spot radius of the minimum light spot of a light cone formed by light emitted by the object point after passing through a lens; for the data, the processing method of data fitting is used for obtaining the minimum light spot center 3 coordinate R of a light cone formed by light emitted by any object point after passing through a lensλ(r,z)、ΦλPhi + pi and Zλ(r, z) and minimum spot radius aλ(r, z), both of which are functions of the coordinates of the object point; in a first coordinate system Zλ(r, z) < 0; the indices λ 1,2,3 represent blue, green and red light, respectively;
when the coordinate z of the object point is > 0, the central coordinate R of the light spotλ(r, Z) and Zλ(r, z) and spot radius aλ(r, z) is substantially no longer affected by z; for light with different colors emitted by the same object point, the coordinates and the sizes of the generated light spots have some differences;
light rays emitted by the object point are focused to form a light cone after passing through the lens, the outer surface of the light cone near the minimum light spot 2 is approximate to a hyperboloid, and the hyperboloid is formed by rotating the hyperboloid around the central axis of the light cone; assuming that the expression of the hyperbola is
Figure BDA0003552300910000081
The plane represented by v ═ 0 is the first section, i.e. the plane in which the minimum spot 2 of the light cone lies; a plane d away from the first section is a second section of the light cone, and the area of a circular light spot intersected with the second section and the light cone is
Figure BDA0003552300910000082
S2: the photosensitive element of the camera comprises a plurality of pixels, and each pixel is formed by sequentially superposing photosensitive layers for sensing blue light, green light and red light from outside to inside. Taking a picture at magnification m x n, where m is the fixed magnification of a fixed focus lens, it is necessary to see the pixels of the photosensitive element as consisting of n circular sub-pixels of approximately equal area, each pixel corresponding to an object point of limited size which, in the in-focus situation, irradiates light onto the pixel, the n sub-pixels of each pixel corresponding to the n sub-object points of the object point. Each pixel senses the light energy emitted by the corresponding object point and converts the light energy into an output electric signal;
s3: each time of shooting, the electric signal of a certain color light output by any pixel is the sum of electric signals generated by the sub-object points corresponding to the object points emitting the light of the color on the corresponding sub-pixels; the distance between the lens and the photosensitive element is changed for shooting n times, and for each color of light, any pixel generates an n-element one-time non-homogeneous linear equation system of the sub-pixel electric signals of the pixel. Three photosensitive layers corresponding to the photosensitive elements and having blue, green and red light, each pixel generating n-element one-time non-homogeneous linear equation set of three sub-pixel electric signals;
s4: solving a set of sub-pixel electrical signal equations for a number of pixels, wherein each pixel generates electrical signals for 3n sub-pixels, where n is the number of sub-pixels per pixel and 3 refers to the three colors blue, green, and red;
s5: the electrical sub-pixel signals for the set of pixels are processed by an image processing program to obtain a picture at a magnification of m x n.
S3 method for generating electric signals for the pixels and sub-pixels of the light receiving element:
the light received by any pixel is from an object point with a certain size at a distance, a photosensitive layer which senses different colors of each pixel is considered to be composed of n sub-pixels with approximately equal areas and basically no overlapping, the object point irradiated on the pixel under the focusing condition is also considered to be composed of n sub-object points with approximately equal areas and basically no overlapping, and light cones obtained after the light emitted by the sub-object points of the object point is focused by a lens are in one-to-one correspondence with the sub-pixels of the pixel, so that the area of the pixel is required to be far larger than the area of the minimum light spot of the light cone obtained after the light emitted by a far extremely small point light source is focused by the lens; the electric signal output by any pixel is the linear superposition of n light cone light energies obtained after the light emitted by n sub-object points of the object point with limited size corresponding to the pixel is focused by the lens.
The method for calculating the electric signal generated by the sub-pixel of any one of the pixels of S3 includes:
in the second coordinate system, according to the specific arrangement position of the pixels of the photosensitive element, the central coordinate of any pixel on the photosensitive element and the polar coordinate of the center of the sub-pixel with n areas approximately equal and not overlapping each other on each pixel can be obtained
Figure BDA0003552300910000091
α is an index of the tag pixel, i is 1,2, …, and n is the ith sub-pixel of the tag pixel.
Continuously shooting n times by changing the distance between the lens and the photosensitive element, wherein the photosensitive layer plane of the photosensitive element and the XOY plane of the first coordinate system, i.e. the plane perpendicular to the central part of the lens and the optical axis, are parallel to each other and have a distance of Zλ,jThe index λ refers to a photosensitive layer for sensing different colors of light, j is 1,2, …, n marks n different distances; the coordinate Z of the minimum light spot center of the light cone after the light emitted by the neutron object point in the first coordinate system is focused by the lensλ(R, z) < 0, the effective radius of the lens is R, the surface area of a single pixel of the photosensitive element is Sc(ii) a The cosine of an included angle between the central axis of a light cone with the color of lambda and the vertical Z axis, which corresponds to the ith sub-pixel irradiated on the alpha-th pixel, is as follows:
Figure BDA0003552300910000092
the central point (R) of the light cone of the ith sub-pixel of the alpha pixel is irradiatedλ(r,z),Zλ(r, z)) a distance along the cone axis to the center of the ith sub-pixel:
Figure BDA0003552300910000093
simultaneously satisfies the relationship:
Figure BDA0003552300910000094
the minimum spot plane color of the light cone illuminating the ith sub-pixel of the alpha pixel is λ:
Figure BDA0003552300910000095
herein Iλ,α,iRefers to the average intensity of light impinging at the minimum spot of the light cone of color λ of the ith sub-pixel of the alpha-th pixel, and δ t refers to the time interval of illumination. Since the light energy impinging on the pixels is converted into an electrical output signal in a fixed ratio, the light energy referred to in this patent is equivalent to the electrical signal generated. Defining:
Figure BDA0003552300910000101
(ii) a The electrical signal generated in the light sensing time deltat when the light cone with the color of lambda irradiates the ith sub-pixel of the alpha pixel is as follows:
Figure BDA0003552300910000102
here, the
Figure BDA0003552300910000103
Means for varying the distance Z between the plane of the sensitive layer and the lensλ,jMeanwhile, the light irradiated to the ith sub-pixel of the alpha-th pixel is irradiated to the periphery of the pixel, and the light originally irradiated to the periphery of the pixel is irradiated to the ith sub-pixel of the pixel to influence the electric signal. Stipulate in a certain
Figure BDA0003552300910000104
When the camera is in focus, all the cameras are in focus
Figure BDA0003552300910000105
In addition, when the pixel subpixel n is relatively large, the subpixels that are not at the pixel edge are
Figure BDA0003552300910000106
Can also be considered approximately as 1, so only for sub-pixels at the edge of the pixel
Figure BDA0003552300910000107
Requiring specific experimentation or simulation.
The calculation method of the electrical signal equation set of S3 and the generation method of the photo are as follows:
when each pixel of the photosensitive element is considered to be composed of n sub-pixels, i.e. to take a picture at a magnification of m × n, it is necessary to change the distance Z between the plane of the photosensitive layer of the photosensitive element and the plane of the lensλ,jJ 1,2 …, n, the electrical signal T output by the pixel is recordedλ,j,α(ii) a Output electric signal T of photosensitive layer of any pixel alpha sensing lambda colorλ,j,αEqual to the sum of the sub-pixel output electrical signals of the pixel, i.e.:
Figure BDA0003552300910000108
for any pixel alpha, when lambda is 1, namely corresponding to the blue photosensitive layer, j is taken from 1 to n, namely the distance Z between the photosensitive layer and the lens plane is changedλ,jAnd shooting for n times to obtain n similar equations which jointly form an n-order linear non-homogeneous equation set of the sub-pixel blue-light electric signals of the pixel. And when the value of the lambda is 2 and 3, obtaining an n-order linear non-homogeneous equation set of the green light electric signals and the red light electric signals of the sub-pixels of the pixel. The equations for these three lights are obtained simultaneously n shots, and each pixel produces three such electrical signal equations. Solving the system of equations for the sub-pixel electrical signals for N pixels (numbered 1,2 …, N) to obtain N sets of electrical signals:
Figure BDA0003552300910000111
the set of data comprises 3nN Qλ,α,iFrom these 3nN Qλ,α,iAfter the treatment, a photograph with a magnification of m × n was obtained. The N pixels are typically selected at the center of the photosensitive element, the specific number of pixels being determined by how many times the picture is taken and the pixels of the picture, the total pixels of the picture being equal to nN.
If the magnification of the lens is 3, a picture is taken at 27 times magnification, i.e. n is 9, resulting in a total picture of 1.2 × 10 pixels7The number of pixels to be selected is 1.2X 107/n＝1.3×106The number of the 9-element non-homogeneous linear equation sets to be solved is 3.9 multiplied by 106。
Example 2: as shown in fig. 1, the coordinate system is a first coordinate system, and the central coordinate and the radius of the light spot of the light source with the color λ at a distance are measured after the light is focused by the camera lens.
Example 3: referring to FIG. 2, a light cone of a point light source with a color λ at a far distance after passing through a lens can be approximately described by a hyperboloid formed by rotating a hyperboloid, the distance between the light cone and the light cone is d, and the cross-sectional area of the light cone perpendicular to the light cone axis is
Figure BDA0003552300910000112
aλ(r, z) is the minimum spot radius of the cone of light.
Example 4: as shown in fig. 3, the first coordinate system is moved as a whole along the z-axis so that the XOY plane coincides with the photosensitive layer of the corresponding color of the photosensitive element, resulting in a second coordinate system. In the first coordinate system, the coordinate of the light cone after the point light source with the far color of lambda passes through the lens for focusing is (R)λ,Φλ,Zλ). In the second coordinate system, the object point 1 is regarded as a point light source, and the center 3 of a light cone formed by light of the point light source with the distant color of lambda passing through the lens is coordinated as
Figure BDA0003552300910000113
Z hereinλ,jIs the distance between the XOY planes of coordinate system one and coordinate system two. In the second coordinate system, the coordinates of the center of the pixel 4 and its n sub-pixels of the photosensitive layer
Figure BDA0003552300910000121
Can be established.
Example 5: as in fig. 4, a single pixel is seen to be composed of n sub-pixels, where n is also a magnification factor that is again based on the lens fixed magnification factor. The maximum magnification factor m of the camera lens of the current mobile phone can reach 3.5, which indicates that n is more than or equal to 4.
Example 6: the spot area of the point light source is far smaller than the area of the single pixel 4; the distance between the plane of the photosensitive layer and the plane of the lens of the pixel 4 is Zλ,jThe index j is 1,2, …, and n indicates that n different distances are taken. Since the distance between the three photosensitive layers is fixed, Z is variedλ,jThe distance between the three photosensitive layers and the lens is changed at the same time;
according to the specific arrangement position of the pixels on the photosensitive layer, the central coordinate of any pixel on the photosensitive element and the polar coordinate of the center of n sub-pixels of each pixel are obtained
Figure BDA0003552300910000122
The cosine of an included angle between the central axis of a light cone with the color of lambda of the ith sub-pixel irradiated on the alpha-th pixel and the vertical Z axis is as follows:
Figure BDA0003552300910000123
the central point (R) of the light cone of the ith sub-pixel of the alpha pixel is irradiatedλ(r,z),Zλ(r, z)) distance along the cone axis to the ith subpixel center:
Figure BDA0003552300910000124
satisfy the relationship at the same time
Figure BDA0003552300910000125
A light cone with color lambda is irradiated onThe electric signal generated by the ith part of the alpha pixel in the sensitization time deltat is as follows:
Figure BDA0003552300910000126
wherein
Figure BDA0003552300910000127
Figure BDA0003552300910000128
Z at the center of the cone of light in a first coordinate systemλ(R, z) < 0, R is the effective radius of the lens, ScIs the area of a single pixel;
Figure BDA0003552300910000131
means for varying the distance Z between the plane of the photosensitive layer and the plane of the lensλ,jWhen the pixel is in a normal state, the light irradiating the ith sub-pixel of the alpha pixel irradiates the periphery of the pixel, and the light irradiating the periphery of the pixel originally irradiates the ith sub-pixel of the pixel; provision for focusing
Figure BDA0003552300910000132
In the case of a non-in-focus situation,
Figure BDA0003552300910000133
the correction is mainly generated for sub-pixels at the edges of the pixel, in which case it can be determined by experiment or simulation
Figure BDA0003552300910000134
Qλ,α,iIt can be understood that the electrical signal generated in the light sensing time deltat when the light cone with the color of lambda irradiates the ith sub-pixel of the alpha-th pixel is the quantity to be solved;
when the pixel of the photosensitive element is considered to be composed of n sub-pixels, and the distance between the plane of the photosensitive element and the plane of the lens is Zλ,jThe total electric signal T generated for any pixel alpha, lambda colorλ,j,αCan be expressed as:
Figure BDA0003552300910000135
varying the distance Z between the photosensitive element and the lensλ,jThe index j being 1, …, n, i.e. n different Zλ,jTaking a picture, recording n electric signals Tλ,j,αObtaining a set of n-element linear non-homogeneous equation of alpha pixel light related to lambda color, and solving the equation set to obtain n Qλ,α,i(ii) a The blue, green and red lights correspond to one equation set, the blue-green and red electric signals of n sub-object points corresponding to the pixel can be obtained from one pixel by solving the three equation sets, and the photo pixels of the n sub-object points are obtained after processing. And selecting a group of pixels with proper quantity to perform similar operation to obtain nN picture pixels, namely the optical zoom multiple of the picture is increased by n times on the basis of the lens zoom multiple.
Example 7: the mobile phone rear camera is provided with a plurality of lenses, such as a wide-angle lens and a macro lens, and a lens combination with optical zooming of 1,2 and 3 times respectively, when the value range of n is 4-10, the optical zooming times which can be realized by the lens with the optical zooming of 1 time are as follows: 4,5,6,7, 9; the optical zoom factor that can be realized by the lens with the optical zoom of 2 times is as follows: 8,10,14,16, 20; the optical zoom factor that can be realized by the lens with 3 times of optical zoom is as follows: 12,15,18,21,24,27, 30; the optical zoom factor can be seen, the camera of the mobile phone can be approximately continuously zoomed in a large range.
Example 8: the device for continuous optical zooming based on the fixed-focus lens comprises a lens, a photosensitive element, a moving assembly and a controller; the photosensitive element comprises three layers of photosensitive materials which are stacked and sequentially sense blue light, green light and red light; the lens is arranged between the photosensitive element and the object point, and a main optical axis of the lens penetrates through the center of the photosensitive side of the photosensitive element; the moving assembly is clamped with the edge of the lens; the moving assembly is electrically connected with the controller.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (5)

1. A method for realizing large-range continuous optical zooming based on a fixed-focus lens is characterized by comprising the following steps:
the method comprises the following steps of taking a picture with an equivalent zooming multiple of mxn by using a lens with a fixed optical zooming multiple of m, wherein the specific method for carrying out simulated zooming processing in the process comprises the following steps:
s1: the object point is regarded as a luminous point light source; in a first coordinate system, the coordinates of the point light source in the first coordinate system are (r, phi, z), wherein z > 0; for any object point, light emitted by the object point is refracted through the lens to form a light cone, the plane of the minimum light spot of the light cone is perpendicular to the central axis of the light cone, and the shape of the minimum light spot is approximately circular;
according to the circular symmetry of the rotation around the optical axis of the lens, the optical axis of the lens is the Z axis of the first coordinate system, and only the set of a large number of object points with fixed phi angles needs to be considered; the plurality of object points have different r and z coordinates; for each object point, accurately measuring the central coordinate and the light spot radius of the minimum light spot of a light cone formed by light emitted by the object point after passing through a lens; for the data, the minimum spot center coordinate R of a light cone formed by light emitted by any object point after passing through a lens can be obtained by using a data fitting processing methodλ(r,z)、ΦλPhi + pi and Zλ(r,z)And minimum spot radius aλ(r, z), both of which are functions of the coordinates of the object point; in a first coordinate system Zλ(r, z) < 0; the indices λ 1,2,3 represent blue, green and red light, respectively;
when the coordinate z of the object point is > 0, the central coordinate R of the light spotλ(r, Z) and Zλ(r, z) and spot radius aλ(r, z) is substantially no longer affected by z; for light with different colors emitted by the same object point, the coordinates and the sizes of the generated light spots have some differences;
the light rays emitted by the object point are focused to form a light cone after passing through the lens, the outer surface of the light cone near the minimum light spot is approximate to a hyperboloid, and the hyperboloid is formed by rotating the hyperboloid around the central axis of the light cone; assuming that the expression of the hyperbola is
Figure FDA0003552300900000011
The plane represented by v ═ 0 is the first section, namely the plane where the minimum spot of the light cone is located; the plane d away from the first section is the second section of the light cone, and the area of the circular facula intersected with the second section and the light cone is
Figure FDA0003552300900000012
S2: the photosensitive element of the camera comprises a plurality of pixels, and each pixel is formed by sequentially superposing photosensitive layers for sensing blue light, green light and red light from outside to inside; taking a picture with a magnification of m × n, where m is the fixed magnification of the fixed focus lens, it is necessary to view the pixels of the photosensitive element as being composed of n circular sub-pixels with approximately equal areas, each pixel corresponding to an object point of a finite size that irradiates light onto the pixel, and the n sub-pixels of each pixel corresponding to the n sub-object points of the object point; each pixel senses the light energy emitted by the corresponding object point and converts the light energy into an output electric signal;
s3: each time of shooting, the electric signal of a certain color light output by any pixel is the sum of electric signals generated by the sub-object points corresponding to the object points emitting the light of the color on the corresponding sub-pixels; the distance between the lens and the photosensitive element is changed for shooting n times, and for each color of light, any pixel generates an n-element one-time non-homogeneous linear equation set of sub-pixel electric signals of the pixel; three photosensitive layers corresponding to the photosensitive elements and having blue, green and red light, each pixel generating n-element one-time non-homogeneous linear equation set of three sub-pixel electric signals;
s4: solving a set of sub-pixel electrical signal equations for a number of pixels, wherein each pixel generates electrical signals for 3n sub-pixels, where n is the number of sub-pixels per pixel and 3 refers to the three colors blue, green, and red;
s5: the electrical sub-pixel signals of the set of pixels are processed by an image processing program to obtain a picture at magnification m x n.
2. The method for realizing large-range continuous optical zoom based on the fixed-focus lens as claimed in claim 1, wherein the pixel and sub-pixel electrical signal generation modes of the photosensitive elements of S3 are as follows:
the light received by any pixel is from an object point with a certain size at a distance, a photosensitive layer which senses different colors of each pixel is considered to be composed of n sub-pixels with approximately equal areas and basically no overlapping, the object point irradiated on the pixel under the focusing condition is also considered to be composed of n sub-object points with approximately equal areas and basically no overlapping, and light cones obtained after the light emitted by the sub-object points of the object point is focused by a lens are in one-to-one correspondence with the sub-pixels of the pixel, so that the area of the pixel is required to be far larger than the area of the minimum light spot of the light cone obtained after the light emitted by a far extremely small point light source is focused by the lens; the electric signal output by any pixel is the linear superposition of n light cone light energies obtained after the light emitted by n sub-object points of the object point with limited size corresponding to the pixel is focused by the lens.
3. The method for realizing large-range continuous optical zoom based on the fixed-focus lens as claimed in claim 2, wherein the calculation method of the electrical signals generated by the sub-pixels of any one pixel of S3 is as follows:
in the second coordinate system, according to the specific arrangement position of the pixels of the photosensitive element, the central coordinate of any pixel on the photosensitive element and the polar coordinate of the center of the sub-pixel with n areas approximately equal and not overlapping each other on each pixel can be obtained
Figure FDA0003552300900000031
α is an index of the flag pixel, i is 1,2, …, n designates the ith sub-pixel of the pixel;
continuously shooting n times by changing the distance between the lens and the photosensitive element, wherein the photosensitive layer plane of the photosensitive element and the X-Y plane of the first coordinate system, i.e. the plane perpendicular to the central part of the lens and the optical axis, are parallel to each other and have a distance Zλ,jThe index λ refers to a photosensitive layer for sensing different colors of light, j is 1,2, …, n marks n different distances; the coordinate Z of the minimum light spot center of the light cone after the light emitted by the neutron object point in the first coordinate system is focused by the lensλ(R, z) < 0, the effective radius of the lens is R, the area of a single pixel of the photosensitive element is Sc(ii) a The cosine of an included angle between the central axis of a light cone with the color of lambda and the vertical Z axis, which corresponds to the ith sub-pixel irradiated on the alpha-th pixel, is as follows:
Figure FDA0003552300900000032
the central point (R) of the light cone of the ith sub-pixel of the alpha pixel is irradiatedλ(r,z),Zλ(r, z)) a distance along the cone axis to the center of the ith sub-pixel:
Figure FDA0003552300900000033
simultaneously, the relation is satisfied:
Figure FDA0003552300900000034
the minimum spot plane color of the light cone illuminating the ith sub-pixel of the alpha pixel is λ:
Figure FDA0003552300900000035
herein Iλ,α,iRefers to the ith sub-pixel color illuminated at the alpha pixelThe average intensity at the minimum spot of the light cone of λ, δ t referring to the time interval of illumination; because the light energy impinging on the pixels is converted into an electrical output signal in a fixed ratio, the light energy referred to in this patent is equivalent to the electrical signal generated; defining:
Figure FDA0003552300900000036
(ii) a The electrical signal generated in the light sensing time deltat when the light cone with the color of lambda irradiates the ith sub-pixel of the alpha pixel is as follows:
Figure FDA0003552300900000041
here, the
Figure FDA0003552300900000042
Means for varying the distance Z between the plane of the sensitive layer and the lensλ,jWhen the electric signal is generated, the light irradiating the ith sub-pixel of the alpha pixel irradiates the periphery of the pixel, and the light irradiating the periphery of the pixel originally irradiates the ith sub-pixel of the pixel to influence the electric signal; stipulate at a certain
Figure FDA0003552300900000043
When the camera is in focus, all the cameras are in focus
Figure FDA0003552300900000044
In addition, when the pixel subpixel n is relatively large, the subpixels that are not at the pixel edge are
Figure FDA0003552300900000045
Can also be considered approximately as 1, so only the sub-pixels at the edge of the pixel are considered
Figure FDA0003552300900000046
Requiring specific experimentation or simulation.
4. The method for realizing the large-range continuous optical zoom based on the fixed-focus lens as claimed in claim 3, wherein the calculation method of the electrical signal equation set of S3 and the method for generating the photo are as follows:
when each pixel of the photosensitive element is considered to be composed of n sub-pixels, i.e. to take a picture at a magnification of m × n, it is necessary to change the distance Z between the plane of the photosensitive layer of the photosensitive element and the plane of the lensλ,jJ 1,2 …, n, the electrical signal T output by the pixel is recordedλ,j,α(ii) a Output electric signal T of photosensitive layer of any pixel alpha sensing lambda colorλ,j,αEqual to the sum of the sub-pixel output electrical signals of the pixel, i.e.:
Figure FDA0003552300900000047
for any pixel alpha, when lambda is 1, namely corresponding to the blue photosensitive layer, j is taken from 1 to n, namely the distance Z between the photosensitive layer and the lens plane is changedλ,jShooting for n times to obtain n similar equations which jointly form an n-order linear inhomogeneous equation set of the sub-pixel blue-light electric signal of the pixel; when the value of lambda is 2 and 3, obtaining an n-order linear non-homogeneous equation set of the green light electric signals and the red light electric signals of the sub-pixels of the pixel; the equation sets of the three lights are obtained by shooting n times simultaneously, and each pixel generates three such electric signal equation sets; solving an equation set of sub-pixel electric signals of N pixels, wherein the N pixels are numbered as 1,2 …, N, and obtaining N groups of electric signals:
Figure FDA0003552300900000051
the set of data comprises 3nN Qλ,α,iFrom these 3nN Qλ,α,iObtaining a photo with the magnification of mxn after processing; the N pixels are typically selected at the center of the photosensitive element, and the specific number of pixels is determined by how many times the picture is taken and the pixels of the picture, i.e., the total pixels of the picture equals nN.
5. A device for continuous optical zooming based on a fixed-focus lens is characterized in that,
the method comprises the following steps: the device comprises a lens, a photosensitive element, a moving assembly, a controller and an information processing device; the photosensitive element comprises three layers of stacked photosensitive materials which sequentially sense blue light, green light and red light; the main optical axis of the lens penetrates through the center of the photosensitive side of the photosensitive element; the moving assembly is clamped with the edge of the lens; the moving assembly is electrically connected with the controller; the photosensitive element is electrically connected with the information processing device.
CN202210265037.1A 2022-03-17 2022-03-17 Method and device for realizing large-range continuous optical zooming based on fixed-focus lens Pending CN114529458A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116125691A (en) * 2023-04-04 2023-05-16 南昌虚拟现实研究院股份有限公司 Quick zooming method and system of zoom lens, electronic equipment and storage medium

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116125691A (en) * 2023-04-04 2023-05-16 南昌虚拟现实研究院股份有限公司 Quick zooming method and system of zoom lens, electronic equipment and storage medium
CN116125691B (en) * 2023-04-04 2023-06-30 南昌虚拟现实研究院股份有限公司 Quick zooming method and system of zoom lens, electronic equipment and storage medium

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