Method for designing miniature lenses with appropriate distortion and imaging device

Abstract

Method for generating a processed image with a target resolution using an imaging device (1130) comprising an image transmitter (1120) and a processing unit (1150), wherein the image transmitter (1120) comprises a miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) and an image sensor, wherein the method comprises: a. Creating an optical image of a scene in an image plane (530, 730) using the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728), wherein the optical image has an original resolution curve (610, 810), where a resolution curve represents the resolution as a function of the field of view angle; b. Converting the optical image through the image sensor into an original digital image file with the original resolution curve (610, 810); c. Receiving the original digital image file, information about the original resolution curve (610, 810) and information about a target resolution curve (620, 820) by the processing unit (1150); and d. Processing the original digital image file by the processing unit (1150) to produce a processed image (1170), wherein the processing unit (1150) transforms the original resolution curve (610, 810) into the target resolution curve (620, 820); wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) has a miniaturization ratio that is expressed as the ratio between a total track length and an image section diameter (560, 760).is defined, wherein the total track length is defined as the distance from either the object-side vertex of the first optical element (512, 712) or the aperture (510, 710), whichever is farther away on the object side, to the image plane (530, 730), wherein the image area diameter is represented by the distance between the points (537, 538, 737, 738) on the image plane (530, 730) where the rays (507, 508, 707, 708) defining half the field of view of the lens intersect the image plane (530, 730), wherein the miniaturization ratio is less than 0.8, and wherein the original resolution curve (610, 810) has a value that is at least 10% smaller than a corresponding value of the target resolution curve (620, 820) at a center of a field of view.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 871,978, filed July 9, 2019, entitled "Method for Designing Miniature Lenses with Purposeful Distortion," currently pending, the entire contents of which are incorporated herein by reference. GENERAL STATE OF THE ART

[0002] Embodiments of the present invention relate to the field of optical lenses and their embodiment, and more particularly to panoramic miniature lenses having a wide-angle field of view of about 60° or more used in combination with image processing.

[0003] Designing imaging lenses for use in modern smartphones or other space-constrained applications all presents the challenge of requiring a large imager diameter while keeping the overall lens thickness as small as possible, which in optical design is also known as the total track length (TTL). Especially for modern smartphones or consumer electronics, the thickness of the lenses is usually limited to a total length of less than 10 mm to prevent the lens from protruding from the thin devices. Regarding the field of view, the trend towards image sensors with ever-increasing megapixel counts is also driving the size of the sensors. Therefore, the lenses must have the smallest possible miniaturization ratio, defined as the ratio between the total track length and the field of view diameter.

[0004] For existing wide-angle lenses with a total field of view between 60° and 100° and ultra-wide-angle lenses with a total field of view between 100° and 170°, the miniaturization ratio is generally 0.8 or more. For a fixed image sensor size with a fixed half-diameter of the image field with a height H, this miniaturization ratio is generally limited by the required focal length f of the lens to follow a rectilinear projection H=f*tan(θ), as is often required in mobile phones, as this is often considered the most comfortable viewing angle.

[0005] A new method for designing miniature wide-angle lenses and ultra-wide-angle lenses is needed to achieve miniaturization ratios of less than 0.8, especially when the lenses are used in combination with image processing to improve the display projection of the image when it is insufficient for comfortable viewing.

[0006] US 2017 / 0184813 A1 discloses miniature wide-angle lenses and methods for their manufacture. SUMMARY OF THE INVENTION

[0007] To overcome all of the aforementioned problems, embodiments of the present invention provide a method for designing wide-angle or ultra-wide-angle optical systems with a miniaturization ratio of less than 0.8. For the purposes of this invention, a wide-angle optical system is considered to be an optical system with a full field of view between approximately 60° and 100°, and an ultra-wide-angle optical system is considered to be an optical system with a full field of view between approximately 100° and 170°. However, both the lower limit of 60° and the upper limit of 170° for these two categories are examples of the usual range and are not absolute values ​​that limit the concept of the present invention. Wide-angle and ultra-wide-angle optics are also called panoramic optics because their large field of view allows a large portion of the scene to be captured with a single shot.The degree of miniaturization is defined as the ratio between the total track length (TTL) and the diameter of the image base of these optical systems. The optical systems can be of any type, including pure lenses that use only refraction to guide light from the task to the image, optical systems that use a combination of refraction and diffraction, optical systems that use a diffractive optical element, optical systems with metamaterials or metasurfaces, or the like. In a preferred embodiment, the optical system is an optical lens consisting of only one lens element.

[0008] To reduce the degree of miniaturization, the designed wide-angle or ultra-wide-angle lens can either reduce the total track length or increase the diameter of the image area. However, for a given lens design, the image sensor is often dictated by the application, as the number and size of pixels determine what can be achieved with that optical system. The only remaining way to reduce the degree of miniaturization is to reduce the overall length of the system. To achieve this, the method of the present invention deliberately reduces the focal length of the system to obtain a smaller total track length and achieve a miniaturization ratio below 0.8.For miniature wide-angle and ultra-wide-angle lenses, the focal length is reduced by at least 10% compared to the focal length of the system that generates the target projection for a given image sensor, resulting in a resolution at the center that is at least 10% below the resolution of the target resolution curve.

[0009] In some embodiments, the method according to the present invention is used to design extreme miniature wide-angle lenses or extreme miniature ultra-wide-angle lenses, where the focal length can be further reduced to at least 15% lower than the focal length of the system required for the target projection onto a particular image sensor, or even to at least 20% lower than the focal length of the system generating the target projection. In some other embodiments of extreme miniature wide-angle lenses or extreme miniature ultra-wide-angle lenses, not necessarily related to the above-mentioned reduced focal length embodiments, the miniaturization ratio is less than 0.7. In some other embodiments, the method of the present invention is taken even further, and the miniaturization ratio is at least less than 0.6 or even less than 0.5.

[0010] In addition to a shorter focal length resulting in lower resolution in the center of the field of view so that the image covers the same diameter of the image area on the image plane for a fixed overall field of view, the reduction in focal length resulting in a compression zone in the center is combined with appropriate distortion to create at least one expanded zone in the remaining field of view where the resolution of the designed lens is greater than the target resolution for the application.

[0011] Once the miniature wide-angle or miniature ultra-wide-angle lens according to the present invention is designed and manufactured, it can be used in a camera system to generate an image on an image sensor with appropriate distortion to create a compressed zone in the center and at least one expanded zone in the remainder of the field of view. This image sensor is used to create a digital image file of the optical image of the lens with appropriate distortion. This original digital image file can then be used in combination with an image processing and deblurring algorithm to create a processed and deblurred image in which the resolution profile has been converted from the original to the target resolution profile. The algorithm can also be used to perform other image processing techniques to further improve the image quality of the output image.Finally, the image output by the algorithm unit can either be displayed to a human observer or used automatically within a computation unit without a human seeing the image.

[0012] In some other embodiments of the present invention, the deskewing may be performed directly by the image sensor, rather than using the image sensor to create a digital image file with appropriate distortion, to which an image processing and deskewing algorithm is applied. One way the sensor can perform deskewing directly is by directly transforming the pixels read during a line-by-line scan, a circular scan, or a matched pixel scan, so that the sensor's output is already deskewed. Another way the sensor can perform deskewing directly is through smart binning, where the image sensor can, for example, apply different binning in the center than at the edges. It could be a 1x1 pixel (no binning) in the center, increasing to 1.5x1.5 pixels or 2x2 pixels towards the edges.Smart binning could also use non-symmetric binning, such as 1×2 or 2×1 pixel binning. This smart binning at the analog sensor level, rather than through software image processing, improves the resulting signal-to-noise ratio. Finally, sensor-side distortion correction could be achieved by using an image sensor whose pixels progressively increase in size toward the edges. For example, the pixels in the center could be square at 1×1 µm, but toward the edges, the size could be larger than 1 µm, or the shape could be different from the square pixels. BRIEF DESCRIPTION OF THE MULTIPLE VIEWS OF THE DRAWINGS

[0013] The foregoing summary, as well as the following detailed description of a preferred embodiment of the invention, will be better understood when read in conjunction with the accompanying drawings. For purposes of illustration, there is shown in the drawings an embodiment that is presently preferred. It should be understood, however, that the invention is not limited to the arrangements and instrumentalities shown.

[0014] In the drawings: Fig. Figure 1 shows the optical layout of an existing 80° wide-angle lens with a miniaturization ratio of 0.9; Fig. Figure 2 shows a typical resolution curve for an existing 80° wide-angle lens with a miniaturization ratio >0.8; Fig. Figure 3 shows the optical layout of an existing 120° ultra-wide-angle lens with a miniaturization ratio of 0.9; Fig. Figure 4 shows a typical resolution curve for an existing 120° ultra-wide-angle lens with a miniaturization ratio >0.8; Fig. 5 shows an example of the optical layout of a miniature 80° wide-angle lens having a miniaturization ratio of 0.6; Fig. Figure 6 shows an exemplary resolution curve for a miniature 80° wide-angle lens having a miniaturization ratio <0.8 compared to the target resolution curve after image processing; Fig. 7 shows an example of the optical layout of a 120° ultra-wide-angle lens having a miniaturization ratio of 0.6; Fig. Figure 8 shows an exemplary resolution curve for a 120° ultra-wide-angle lens having a miniaturization ratio <0.8 compared to the target resolution curve after image processing; Fig. 9 shows the method of processing an image captured by an imager into an image with the target projection by image processing; Fig. 10 shows the method for converting an image captured by an image generator into an image with the target projection via the image sensor and the processing unit; and Fig. 11 shows an exemplary embodiment of a physical device that captures an image at the original resolution, processes it, and outputs the processed image at the target resolution. DETAILED DESCRIPTION OF THE INVENTION

[0015] The words “a” and “an” as used in the claims and in the relevant parts of the description mean “at least one”.

[0016] Fig. Figure 1 shows the layout 100 of a typical wide-angle lens used in a mobile phone application according to the prior art. The lens has an object side on the left side of the layout and an image side on the right side of the layout. In this example layout, the optical design consists of an aperture 110, six aspherical plastic elements 112, 114, 116, 118, 120, and 122, a sensor cover glass that can also function as a filter 128, and an image plane 130. Rays 105 emanating from the object in a direction perpendicular to the image plane 130 represent a central field of view on the optical axis of the lens, corresponding to a field of view of 0°. Rays 107 and 108 emanating from the object with oblique incidence relative to the image plane 130 define the maximum half field of view of the lens.In this example, these rays 107 and 108 are at an angle of ±40° to the optical axis, corresponding to a full field of view of 80°. This is an example value commonly encountered in prior art, but from now on, a wide-angle lens will be considered a lens that has a full field of view between approximately 60° and 100°. The lens in optical layout 100 has a total track length represented as the distance from either the object-side vertex of the first optical element 112 or the aperture 110, whichever is farther on the object side, to the image plane 130 and is represented in the layout by the length 150. In this example, the aperture is located in front of the first plastic optical element, but the vertex of L1 is still more on the object side of the lens compared to the aperture, and the vertex of L1 is used to limit the total track length.In some other wide-angle lenses, the aperture might be located behind the first optical element. In this case, where the aperture would be located on the image side relative to the first element 112, the total track length 150 would be measured from the apex of the first optical element 112 to the image plane 130. The lens also has a field of view diameter 160, represented by the distance on the image plane 130 between the point 137 where the rays from direction 107 strike the image plane and the point 138 where the rays from direction 108 strike the image plane. In the example layout 100, the miniaturization ratio of these wide-angle lenses, defined as the ratio between the total track length 150 and the field of view diameter 160, is 0.9.For existing wide-angle lenses with a total field of view between 60° and 100°, the miniaturization ratio is above 0.8 and is generally limited by the required focal length f of the lens to follow a rectilinear projection H=f*tan(θ) up to the height H of half the field diameter, as denoted by . Fig. 2 is described.

[0017] Fig. Figure 2 shows the typical target resolution curve 200 in existing wide-angle lenses used in mobile phones according to the state of the art. For simplicity, the resolution curve 200 is normalized with respect to the value at a field of view angle of 0°. The resolution curve is the mathematical derivative of the position curve, also known as the object-image mapping function or distribution function, with respect to the angle of view θ and is also called the magnification curve. For wide-angle lenses with a full angle of view between 60° and 100°, the lenses generally follow the rectilinear projection H=f*tan(θ) for the object-image mapping function as closely as possible, where H is the image height on the image plane measured from the optical axis, f is the focal length of the optical system, and θ is the angle of view.In graph 200, the resolution in the center, at an angle of view of 0°, is represented by the normalized value 210 and corresponds to the focal length f when the resolution before normalization is expressed in mm / radian. This resolution before normalization is often also expressed in pixels / degree, using the pixel size of the sensor. For a perfect rectilinear lens, the normalized value 215 at a half angle of view of 30° is 1.33, the normalized value 220 at a half angle of view of 40° is 1.70, and the normalized value 225 at a half angle of view of 50° is 2.42. The deviation from this ideal projection is commonly referred to as optical distortion. Optical distortion is usually calculated using the following formula. Distortion(%)=100Hreal−HidealHideal

[0018] Here, H real the actual image height of a given imager and H idealthe image height that the same imager would have in a perfect lens H=f*tan(θ). For wide-angle lenses used in mobile phones, distortion is typically kept below ±5% so that straight lines in the imaged object also appear as straight lines in the image. If the field of view of a wide-angle lens must cover the entire diagonal of an image sensor and the entire field of view is a fixed requirement, the required focal length f of the system can be calculated to obtain a lens without distortion. For example, for a conventional 1 / 3" image sensor, which has a diagonal of 6.0 mm, the maximum image height from the center to the corner of the sensor is 3.0 mm. If the entire field of view of this lens is 80°, the maximum half field of view is 40°, and by solving for f in the rectilinear projection equation, we obtain that the focal length ≈3.58 mm need not be a fractional space.While the focal length of a lens is not directly related to the total track length of that lens, it generally follows that a longer focal length requires a longer total track length for a similar design with similar performance, since a longer focal length results in rays with smaller field angles and therefore more track length is required to form a sharp image.

[0019] Fig. Figure 3 shows the layout 300 of a typical ultra-wide-angle lens used in a mobile phone application according to the prior art. The lens has an object side on the left side of the layout and an image side on the right side of the layout. In this example layout, the optical design from task to image consists of a first aspherical plastic element 312, an aperture 310, five further aspherical plastic elements 314, 316, 318, 320, and 322, a sensor cover glass that could also function as a filter 328, and an image plane 330. The rays 305 emanating from the object in a direction perpendicular to the image plane 330 represent a central field of view on the optical axis of the lens, corresponding to a field of view of 0°. Rays 307 and 308, coming from the task with oblique incidence relative to the image plane 128, define the maximum half field of view of the objective.In this example, these rays 307 and 308 are at an angle of ±60° to the optical axis, which corresponds to a full field of view of 120°. This is an example value commonly found in prior art, but from now on, an ultra-wide angle lens will be considered to be a lens that has a full field of view between approximately 100° and 170°. The lens in optical layout 300 has a total track length shown as the distance between the vertex of the first optical element 312 and the image plane 330, represented on the layout by the length 350. In this example, the aperture is located between the first and second plastic optical elements. However, in some other ultra-wide angle lenses, the aperture could be located before the first optical element, after the second optical element, or at any other location thereafter.In the case where the aperture were located to the left of the first element 312, the total track length 350 would be measured from the aperture 310 to the image plane 330. The lens also has a field of view diameter 360, which is represented by the distance on the image plane 330 between the point 337 where the rays from direction 307 strike the image plane and the point 338 where the rays from direction 308 strike the image plane. In the example layout 300, the miniaturization ratio of these ultra-wide angle lenses, defined as the ratio between the total track length 350 and the field of view diameter 360, is equal to 0.9. For existing ultra-wide angle lenses with a total field of view between 100° and 170°, the miniaturization ratio is greater than 0.8 and is generally limited by the required focal length of the lens to limit distortion, as shown in FIG. Fig. 4 is described.

[0020] Fig. Figure 4 shows a typical target resolution curve 400 in an existing ultra-wide-angle lens with a 120° full field of view, which is used in mobile phones according to the state of the art. For simplicity, the resolution curve 400 is normalized with respect to the value at a field of view angle of 0°. The resolution curve is the mathematical derivative of the position curve, also called the object-image mapping function or distribution function, with respect to the angle of view θ and is also called the magnification curve. For ultra-wide-angle lenses with a full angle of view between 100° and 170°, the lenses generally follow as closely as possible the same rectilinear projection H=f*tan(θ) as in Fig. 2 up to a maximum value by half an angle of view of about 40° to 50° and then increasingly lie below the rectilinear projection (negative distortion). In graph 400, the resolution in the center, at an angle of view of 0°, is represented by the normalized value 410 and corresponds to the focal length f if the resolution before normalization is expressed in mm / radian. This resolution before normalization is often also given in pixels / degrees, where the pixel size of the sensor is used. The value of the normalized resolution at the maximum is given by the value 415 and the value at the edge by the value 420. As with the wide-angle lens, the resolution value in the center of the ultra-wide-angle lens (its focal length when calculated in mm / radian) is not directly related to the total track length of this lens.This generally means that a longer focal length also requires a longer total track length for a similar design with similar performance. The required resolution in the center thus limits the minimum total track length.

[0021] Fig. Figure 5 shows an example layout 500 of a wide-angle lens with a small miniaturization ratio using appropriate distortion according to the present invention. In this example layout, the optical design consists of an aperture 510, eight aspherical plastic elements 512, 514, 516, 518, 520, 522, 524, and 526, a sensor cover glass that could also function as a filter 528, and an image plane 530. However, this construction is only an example embodiment according to the present invention, and the method for designing lenses with a low degree of miniaturization is not limited to any number of optical elements, a particular material, or any particular lens shape.In other designs according to the present method, the layout could, for example, have fewer or more than eight optical elements, include elements made of glass, crystal, or other materials, and include spherical elements, freeform elements, mirrors, diffractive elements, elements with metasurfaces, or any other optical element that can contribute to forming an image of the task, including active deformable elements. Rays 505, emanating from the object in a direction perpendicular to image plane 530, represent a central field of view on the optical axis of the lens, corresponding to a field of view angle of 0°. Rays 507 and 508, coming from the task at oblique incidence relative to image plane 530, define the maximum half field of view of the lens. In this example, these rays 507 and 508 are at an angle of ±40° to the optical axis, corresponding to a full field of view of 80°.This value of 80° is an example of a complete field of view for a miniature wide-angle lens according to the present invention, but the method is not limited to a wide-angle or ultra-wide-angle field of view and can also be applied to lenses with a field of view of less than 60° or more than 170°. The lens in the optical layout 500 has a total track length, which is represented as the distance from either the object-side vertex of the first optical element 512 or the aperture stop 510, whichever is farther on the object side, to the image plane 530 and is represented in the layout by the length 550. In this example, the aperture stop is located in front of the first plastic optical element, but the vertex of L1 is still more on the object side of the lens compared to the aperture stop, and the vertex of L1 is used to limit the total track length.In some other wide-angle lenses, the aperture could be located behind at least one optical element. In this case, where the aperture were not the first element, the total track length 550 would be measured from the apex of the first optical element 512 to the image plane 530. The rays from directions 507 and 508 converge to form an image at the image plane 530, each in a small area represented by positions 537 and 538. In each bundle of rays coming from directions 505, 507, and 508, there is a chief ray that passes through the center of the aperture 510. In the area between the sensor cover 528 and the image plane 530, which is generally an air space, the chief rays striking the image plane at 537 and 538 each have an angle of incidence with respect to the chief ray striking the image plane at 535, which is generally the optical axis of the system.This angle is often referred to as the chief ray angle. In some embodiments of miniature wide-angle lenses according to the present invention, the maximum chief ray angle is over 20°, i.e., the rays incident at 537 and 538 form a total aperture angle of at least 40°. The lens also has a field of view diameter 560, which is represented by the distance on the image plane 530 between the point 537 where the rays from direction 507 strike the image plane and the point 538 where the rays from direction 508 strike the image plane. In the example layout 500, the miniaturization ratio of these miniature wide-angle lenses, defined as the ratio between the total track length 550 and the field of view diameter 560, is 0.6.In miniature wide-angle lenses according to the present invention, the miniaturization ratio is below 0.8 by using a focal length at least 10% smaller than that required for the target distortion profile, as shown in . Fig. 6. When the method according to the present invention is further advanced, the miniaturization ratio is below 0.7 for extremely miniature wide-angle lenses. In some other embodiments, the miniaturization ratio is below 0.6 or even below 0.5 in order to achieve an even smaller total track length for a required image diameter. For these extremely miniature wide-angle lenses, the focal length can be at least 15% or even at least 20% smaller than required for the desired distortion profile. Furthermore, for lenses designed according to the method of the present invention, a local telephoto ratio (LTR) can be defined as the ratio between the total track length (TTL) of the lens and the local focal length (LFL) of the lens.The local focal length is defined as the mathematical derivative dH / dθ, where H is the image height in mm and θ is the image angle in radians and corresponds to the traditional effective focal length at the center where the image angle is 0°. Since the local focal length has a specific value for each image angle, the local telephoto ratio also has a specific value, which can vary with the image angle. For lenses designed according to the method of the present invention, the local telephoto ratio at the center is at least 10% higher than at the image angle with the highest resolution. In other embodiments, this LTR at the center is even at least 15% or at least 20% higher than in the field of view with the maximum resolution in order to achieve the desired miniaturization ratio.

[0022] Fig. Figure 6 shows a graph 600 of the normalized original resolution curve 610 (solid line) for a miniature wide-angle lens with a full 80° field of view designed according to the method of the present invention compared to the target resolution curve 620 (dashed line) after processing the image. This target resolution curve 620 also represents the case of a wide-angle lens not designed according to the method of the present invention to achieve the miniaturization ratio as in Fig. 2. The value 612 represents the original resolution of the lens designed according to the method of the present invention at the center of the field of view and is at least 10% lower than the target resolution value 622 of the target resolution curve because the focal length is at least 10% smaller than required for an ideal rectilinear lens. This creates a zone of compression in the center of the image. In some other embodiments of the present invention, for extremely miniature wide-angle lenses, the original resolution of the lens 612 is at least 15% lower than the target resolution 622, or even at least 20% lower than the target resolution 622. Since the original resolution is lower in the center and the size of the image sensor is fixed, this lower original resolution in the center, which creates a compressed region in the center, is combined with at least one expansion region in the remaining part of the field of view.In the example resolution curves 600 from . Fig. 6, the original resolution curve 610 of the lens according to the present invention is equal to the target resolution curve 620 at a single position 630. This equal resolution position 630 separates the compression zone extending from the center of the field of view to this equal resolution position 630 from the expansion zone extending from this equal resolution position 630 to the edge of the field of view. This case with only one equal resolution position 630, where the original resolution of the designed miniature wide-angle lens and the target resolution curve are equal, is only an example, but for other miniature wide-angle lenses designed according to the present method, there could be more than one such equal resolution point.In the expansion zone, there is at least one location where the resolution deviation between the original resolution curve 610 for the designed miniature wide-angle lens and the target resolution curve 620 for the target projection is a local maximum. In this example, from . Fig. 6, a local maximum resolution deviation is located at the edge of the field of view, where half the field of view angle θ is equal to 40°, but a local maximum resolution deviation could be located at any position in the extension zone according to the present invention. At the position of at least one local maximum resolution deviation, the original resolution value 614 of the designed miniature wide-angle lens is at least 10% greater than the target resolution value 624. For extreme miniature wide-angle lenses, the original resolution value 614 could be at least 15% higher than the target resolution value 624, or even at least 20% higher than the target resolution value 624. The image recorded on the image sensor with the original resolution curve 610 of the designed miniature wide-angle lens is then processed using the method described in Fig. 9 or Fig. 10, into an image with the target resolution curve 620.

[0023] Fig. Figure 7 shows an example layout 700 of an ultra-wide-angle lens with a small miniaturization ratio using appropriate distortion according to the present invention. In this example layout, the optical design consists of an aperture 710, six aspherical plastic elements 712, 714, 716, 718, 720, and 722, a sensor cover glass that can also function as a filter 728, and an image plane 730. However, this construction is only an example embodiment according to the present invention, and the method for designing miniature ultra-wide-angle lenses with a low degree of miniaturization is not limited to any number of optical elements, a specific material, or any lens shape.In other designs according to the present method, the layout could, for example, have fewer or more than six optical elements, include elements made of glass or other materials, and include spherical elements, freeform elements, mirrors, diffractive elements, elements with metasurfaces, or any other optical element that can contribute to forming an image of the task, including active deformable elements. Rays 705, emanating from the object in a direction perpendicular to image plane 730, represent a central field of view on the optical axis of the lens, corresponding to a field of view angle of 0°. Rays 707 and 708, coming from the task at oblique incidence relative to image plane 730, define the maximum half field of view of the lens. In this example, these rays 707 and 708 are at an angle of ±60° to the optical axis, corresponding to a full field of view of 120°.This value of 120° is an example of a complete field of view for a miniature ultra-wide-angle lens according to the present invention, but the method is not limited to a wide-angle or ultra-wide-angle field of view and can also be applied to lenses with a field of view of less than 60° or more than 170°. The lens in optical layout 700 has a total track length, which is shown as the distance between the vertex of the first optical element 712 and the image plane 730 and is represented on the layout by the length 750. In this example, the aperture is located between the first and second plastic optical elements. However, in some other ultra-wide-angle lenses, the aperture could be located before the first optical element, after the second optical element, or at any other location thereafter.In the case where the aperture were located to the left of the first element 712, the total track length 750 would be measured from the aperture 710 to the image plane 730. The rays from directions 707 and 708 converge to form an image in the image plane 730, each in a small region represented by positions 737 and 738. In each bundle of rays coming from directions 705, 707, and 708, there is a chief ray that passes through the center of the aperture 710. In the region between the sensor cover 728 and the image plane 730, which is generally an air space, the chief rays that strike the image plane at 737 and 738 each have an angle of incidence with respect to the chief ray that strikes the image plane at 535, which is generally the optical axis of the system. This angle is often referred to as the chief ray angle.In some embodiments of miniature ultra-wide-angle lenses according to the present invention, the maximum chief ray angle is greater than 20°, i.e., the rays incident at 737 and 738 form a total aperture angle of at least 40°. The lens also has a field of view diameter 760, which is represented by the distance on the image plane 730 between the point 737 where the rays from direction 707 strike the image plane and the point 738 where the rays from direction 708 strike the image plane. In the example layout 700, the miniaturization ratio of these miniature ultra-wide-angle lenses, defined as the ratio between the total track length 750 and the field of view diameter 760, is 0.6.In miniature ultra-wide-angle lenses according to the present invention, the miniaturization ratio is below 0.8 by using a focal length at least 10% smaller than that required for the target distortion profile, as shown in . Fig. 8. When the method according to the present invention is further advanced, the miniaturization ratio is below 0.7 for extremely miniature wide-angle lenses. In some other embodiments, the miniaturization ratio is below 0.6 or even below 0.5 to achieve an even smaller total track length for a required image diameter. For these extremely miniature ultra-wide-angle lenses, the focal length can be at least 15% or even at least 20% smaller than required for the desired distortion profile. Furthermore, for lenses designed according to the method of the present invention, a local telephoto ratio (LTR) can be defined as the ratio between the total track length (TTL) of the lens and the local focal length (LFL) of the lens.The local focal length is defined as the mathematical derivative dH / dθ, where H is the image height in mm and θ is the image angle in radians and corresponds to the traditional effective focal length at the center where the image angle is 0°. Since the local focal length has a specific value for each image angle, the local telephoto ratio also has a specific value, which can vary with the image angle. For lenses designed according to the method of the present invention, the local telephoto ratio at the center is at least 10% higher than at the image angle with the highest resolution. In other embodiments, this LTR at the center is even at least 15% or at least 20% higher than in the field of view with the maximum resolution in order to achieve the desired miniaturization ratio.

[0024] Fig. Figure 8 shows a graph 800 of the normalized original resolution curve 810 (solid line) for a miniature ultra-wide-angle lens designed according to the method of the present invention with a full 120° field of view compared to the target resolution curve 820 (dashed line) after processing the image. This target resolution curve 820 also represents the case of an ultra-wide-angle lens not designed according to the method of the present invention to achieve the miniaturization ratio as in Fig. 4. The value 812 represents the original resolution of the lens designed according to the method of the present invention in the center of the field of view and is at least 10% lower than the target resolution value 822 of the target resolution, since the focal length is at least 10% smaller than that required for the lens with target projection. This creates a compression zone in the center of the image compared to the target projection. In some other embodiments of the present invention, for extreme miniature ultra-wide angle lenses, the original resolution of the lens is at least 15% or even at least 20% smaller than the resolution required for the target projection, since the original resolution 812 may be at least 15% smaller than the target resolution 822 or even at least 20% smaller than the target resolution 822.Because the original resolution at the center is less than required for the target projection, and the image sensor size is fixed, this lower original resolution at the center, which creates a compressed zone in the center, is combined with at least one expansion zone in the remaining part of the field of view. For the example resolution curves 800 of . Fig. 8, the original resolution curve 810 of the lens according to the present invention is equal to the target resolution curve 820 at a single equal resolution position 830. This equal resolution position 830 separates the zone of compression extending from the center of the field of view to this equal resolution position 830 from the zone of expansion extending from this equal resolution position 830 to the edge of the field of view. This case of only one equal resolution position 830, where the original resolution of the designed ultra-wide-angle lens and the target resolution curve are equal, is only an example, but for other ultra-wide-angle lenses designed according to the present method, there could be more than one such point, potentially creating more than one compressed zone or more than one expanded zone.In the expansion zone, there is at least one location where the resolution deviation between the original resolution curve 810 for the designed miniature ultra-wide-angle lens and the target resolution curve 820 for the target projection is a local maximum. In this example, from . Fig. 8, the original resolution curve 810 for the designed miniature ultra-wide-angle lens has a resolution maximum at position 814, and the target resolution curve 820 for the target resolution has a resolution maximum at position 824, but the position of a local maximum resolution deviation, defined as the position at which the difference between the resolution curve of the designed lens and the resolution curve of the target projection is a local maximum in %, is located at position 816 on the original resolution curve 810, corresponding to position 826 on the target resolution curve 820. This at least one local maximum resolution can be located anywhere in the expansion zone according to the present invention.In this example, the deviation between the original resolution 818 and the target resolution 828 at the edge of the field of view, where the half-field-of-view angle θ is equal to 60°, is not a local maximum, but this could also be the case in some other examples according to the present invention. At the position of at least one maximum resolution deviation, the original resolution value 816 of the designed miniature ultra-wide-angle lens is at least 10% greater than the target resolution value 826. For extreme miniature ultra-wide-angle lenses, the original resolution value 816 at the maximum resolution deviation could be at least 15% higher than the target resolution value 826, or even at least 20% higher than the target resolution value 826. The image captured on the image sensor with the original resolution curve 810 of the designed miniature ultra-wide-angle lens is then imaged using the method described in . Fig. 9 or Fig. 10, processed into an image with the target resolution curve.

[0025] Fig. Figure 9 shows the method for deblurring and processing an image captured by an imager according to the present invention into a processed image with the target projection when the processing is performed by an algorithm unit. In the first step 900, an imager is used that includes a miniature wide-angle or miniature ultra-wide-angle lens constructed according to the method described in Fig. 5 to Fig. 8, and comprises an image sensor. The lens configured according to the method of the present invention forms an image in an image plane. In step 910, the image sensor of the imager, located near the image plane of the miniature lens, converts the optical image into an original digital image with appropriate distortion. The image sensor may be any type of device, including CCD, CMOS (Complementary Metal-Oxide Semiconductor), quantum dot, or the like. In some embodiments according to the present invention, both the image plane of the optical system and the image sensor may be curved rather than straight.In step 920, the digital image file with appropriate distortion is recorded either on a hard disk, a solid-state drive, a memory card, or another method of recording digital image files, including uploading it over the internet to cloud-based storage or transferring it directly to an image processor. The digital image file with original image resolution according to the present invention has appropriate distortion compared to the target image resolution, creating a compressed region in the center and at least one expanded region in the remainder of the field of view. In step 930, a defusing and processing algorithm unit receives the original digital image file to defuse it and, optionally, further process it.This de-blurring and processing algorithm may be adaptive, using at least one external parameter, user intent, sensor output, or the like, to adjust the target resolution curve in real time. In some other embodiments, instead of creating a digital image file and transmitting it to the processor, the image could be stored in a buffer to be processed directly by the processor without ever creating a digital image file. This algorithm unit may be software code executing on a hardware processor or a hardware device specifically programmed to perform this de-blurring and processing.These include any hardware capable of converting the digital image, including computers, smartphones, tablets, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), systems on chips (SoCs), any hardware consisting of a central processing unit (CPU) or a graphical processing unit (GPU), or similar. The blurring part of the algorithm removes the purposeful distortion in the image of the designed miniature lens with the original resolution curve to obtain an image with the desired resolution curve. An optional processing part of the algorithm can further enhance the output image by adjusting the sharpness, contrast, brightness, white balance, noise reduction, or other image enhancement operations.The output of the algorithm is step 940 with the processed digital image file that has been deblurred to the target image resolution. This processed and deblurred digital image file can then optionally be displayed in step 950 on an image display device, including a computer screen, a television screen, a tablet screen, a smartphone screen, any other type of screen, by printing, or with any other display device capable of showing the processed and deblurred image to a human viewer. Alternatively, the image output by the algorithm unit with the target resolution curve can be used by another computation unit.This computing unit is a computer capable of automatically analyzing the processed and deblurred digital image file without displaying it to a human observer, including analyzing the image through an artificial intelligence network that may or may not have been trained using deep learning techniques.

[0026] Fig. Figure 10 shows the method for blurring an image captured by an imager according to the present invention into a processed image with an intermediate resolution curve using the image sensor, and further processing the resulting image with an algorithm unit to obtain a processed image with the target resolution curve. In the first step 1000, an imager is used that includes a miniature wide-angle or ultra-wide-angle lens constructed according to the method described in Fig. 5 to Fig. 8, and comprises an image sensor. The lens designed according to the method of the present invention forms an image in an image plane. In step 1010, the image sensor of the imager, which is located near the image plane of the miniature lens, receives the optical image with the original resolution curve. The image sensor can be any type of device, including CCD, CMOS (Complementary Metal-Oxide Semiconductor), quantum dot, or the like. In some embodiments according to the present invention, both the image plane of the optical system and the image sensor can be curved instead of straight. In step 1020, the image sensor deblurs the image and converts it into a deblurred digital image having an intermediate resolution curve. This deblurring by the image sensor can include any type of deblurring, e.g.,by changing the output during pixel readout, by smart binning, by using sensors with pixels of different sizes, or similar. More specifically, if the deblurring is performed directly by converting the pixels read during a line-by-line scan, a circular scan, or any other type of pixel scanning, the sensor's output signal will not correspond 1:1 to the order in which it is read, and the output signal will already be deblurred. Another way the sensor can directly perform deblurring is smart binning, where the image sensor can, for example, apply different binning in the center than at the edges. For example, it could be a 1x1 pixel (no binning) in the center, increasing to 1.5x1.5 pixels or 2x2 pixels towards the edges. Smart binning could also use non-symmetric binning, such as 1x2 or 2x1 pixel binning.By performing this intelligent binning at the analog sensor level rather than through software image processing, the resulting signal-to-noise ratio is improved because more light is collected from the effective pixel area, helping to compensate for the lower relative illumination toward the edges of these lenses with appropriate distortion. Similarly, sensor-side distortion could be achieved by using an image sensor whose pixels get progressively larger toward the edges. For example, the pixels in the center might be 1×1 µm square, but toward the edge the size might be larger than 1 µm, or the shape might be different from the square pixels. Next, in step 1030, the image sensor outputs a digital image file that has the center image resolution after image sensor blurring.This digital image file can then optionally be transferred to a processor for further processing in step 1040 to transform the resolution curve from the intermediate resolution curve to the target resolution curve. According to the present invention, after deblurring by the image sensor, the intermediate resolution curve already corresponds to the target resolution curve, and no further image resolution transformation by the processing unit is required. Likewise, in some other embodiments, instead of creating a digital image file and transmitting it to the processor, the image could be stored in a buffer to be processed directly by the processor without ever creating a digital image file.The output of the processor in step 1050 is a processed and deblurred digital image file, which can then optionally be displayed in step 1060 on an image display device, including a computer screen, a television screen, a tablet screen, a smartphone screen, another screen, by printing, or with another display device capable of displaying the processed and deblurred image to a human viewer. Alternatively, the image output by the algorithm unit can also be used by another computing unit. This computing unit is a computer capable of automatically analyzing the processed and deblurred digital image file without displaying it to a human viewer, including analyzing the image by an artificial intelligence network that may or may not have been trained using deep learning techniques.This mitigation and processing algorithm can be adaptive and use at least one external parameter, user intent, sensor output, or similar to adjust the target resolution curve in real time.

[0027] Fig.11 shows an exemplary embodiment of a physical device 1130 that captures the original image at the original resolution, processes it according to the method of the present invention, and outputs the processed image at the target resolution to a screen. The object scene 1100 is visible through the imager 1120 of the physical device 1130. This physical device can be any device that includes a means to receive, process, and optionally display an original wide-angle image, such as a smartphone, a tablet, a laptop or desktop PC, a handheld camera, or the like. The imager has a total field of view, the angular aperture facing the task, schematically represented by the extreme rays 1110 and 1112. For imagers according to the present invention, the field of view is typically greater than 60°.However, this is not a mandatory requirement according to the present invention, and imagers with smaller field of view angles can also be used. In this exemplary embodiment, the imager consists of at least one optical system and at least one image sensor. In other embodiments, the imager could consist of any other type of digital image generation, including other optical systems with lenses, mirrors, diffractive elements, metasurfaces, or the like, or a processor that creates or generates a digital image file from any source. The optical system in this embodiment is a wide-angle lens consisting of multiple rotationally symmetric optical lenses, but in other embodiments, it could also include at least one freeform element to have a non-rotationally symmetric image surface.The image sensor is located as close as possible to the image plane of the optical system and converts the optical image of the lens, which has the original resolution, into a digital image file with the original resolution 1140. The physical device 1130 also includes a processor 1150 configured to receive the original digital image file 1140, the information about the original resolution curve, and the information about the target resolution curve, and is configured to process the original digital image file 1140 to generate a processed image 1170 by transforming the resolution curve from the original resolution curve to the target resolution curve.In this example, the processor 1150 is a central processing unit (CPU), but in other embodiments, the processing may be performed by any type of processor, including a CPU, GPU, TPU, ASIC, FPGA, or other hardware processor configured to execute software algorithms to perform the aforementioned functions or capable of processing digital image files. In this example, with a physical device 1130, the processed image 1170 is then displayed on a screen 1160 for a human viewer to view.This example of a single physical device 1130 including the imager 1120, the processor 1150, and the display 1160 is only one exemplary embodiment according to the present invention, but these three features could also be part of multiple physical devices between which the digital image file is exchanged via any communication connection to share the digital image file, including, but not limited to, a computer main bus, a hard drive, a solid-state drive, a USB drive, over-the-air transmission via Wi-Fi, or any other means of transferring the digital image file between multiple physical devices.

[0028] In some other embodiments according to the present invention, the optical system comprises at least one freeform optical element without rotational symmetry about an optical axis. The resulting image then does not have the shape of a symmetrical disk. In this case, we can still define a miniaturization ratio as the ratio of the total track length divided by the full image dimension, where the full image dimension is calculated as the distance of the pair of pixels on the image plane separated by the greatest distance, even if this distance is greater than the diagonal of the image sensor in the image plane.In these embodiments, the freeform surface may have any shape, including surfaces defined by sets of polynomials in X and Y or in another similar coordinate system, cylindrical elements with different curvatures in two axes, toroidal elements, surfaces defined point by point with their deflection, slope or curvature by a grid or table, 2D spline or NURBS surfaces, surfaces defined by Zernike or Chebyshev polynomials, pedal surfaces, or any other user-defined mathematical surface that can be used to describe a freeform surface.In these embodiments without rotational symmetry, the original resolution curve and the target resolution curve can be defined on arbitrary straight lines across the image plane in which there is a compressed and an expanded zone in the original resolution curve compared to the target resolution curve.

[0029] In some other embodiments according to the present invention, instead of a single optical system producing a single image, the imager comprises multiple optical systems, each of the optical systems producing a separate image on at least one image sensor. In some embodiments, this could be the case with at least one image sensor sharing the same optical path in several optical elements before being split into multiple optical paths by a special optical element that separates the optical path into more than one path, such as a prism, a microlens array, a diffractive element, or the like, thereby producing multiple images on one or more image sensors. In some other embodiments, this could be multiple completely different optical lenses that do not share a common optical element and each form its own image side by side on one or more image sensors.In all these cases where the image plane is shared, we can still define a miniaturization ratio as the ratio of the total track length divided by the full image dimension, where the full image dimension is calculated as the distance between the pair of pixels on an image plane separated by the greatest distance, even if this distance is greater than the diagonal of the image sensor in the image plane. For multiple image sensors with multiple image planes, a separate miniaturization ratio can be calculated for each image plane in the same way, and at least one optical system is miniaturized according to the method of the present invention.

[0030] In some other embodiments according to the present invention, the large positive distortion intentionally added to the optical lens results in a given amount of light being distributed over a larger area on the image plane, resulting in a lower relative illuminance in that region of the image. Relative illuminance is defined as the amount of light hitting the image plane at a given position relative to the amount of light hitting the image plane at a location of maximum illuminance, often in the center of the field of view.To prevent the lens according to the present invention from having too low a relative illumination toward the edge, which could create a visible illumination difference between the center and the edge of the field of view or an image area with excessive image noise because the sensor gain had to be increased to compensate for the lower relative illumination, the lens according to the present invention can be used with a non-uniform light emitter that intentionally blocks some of the rays in an area of ​​maximum illumination to reduce the amount of light in that area. This reduces the light difference between the region of maximum illumination and the region of minimum illumination and balances the relative illumination curve.This non-uniform light transmitter could be an anti-reflective coating that conveniently has a lower efficiency in one area, an additional optical element added to reflect or absorb more rays in one area, or any other optical way to conveniently limit the illumination in one area to better balance the amount of light and achieve more uniform relative illumination.

[0031] In some embodiments according to the present invention, the optical system designed with appropriate distortion is used to compensate for a drop in image quality toward the edge of the field of view, in addition to achieving a smaller miniaturization ratio. This allows you to reduce the differences in image quality across the entire image. Wide-angle and ultra-wide-angle optical systems typically have decreasing image quality from the center to the edge of the image area because off-axis aberrations become increasingly significant. With the compression zone in the center of the image and the at least one expansion zone toward the edge of the image, the image quality after rectification from the original resolution to the target resolution has the effect of the image expanding in the originally compressed zone and being compressed in the originally expanded zone.In the originally compressed area, the image quality was already high, and digital enhancement in this part of the image still provides good overall image quality in this region. In the originally expanded area, the image quality was lower, and digital compression in this part of the image makes the lower image quality less noticeable by compressing more original pixels of information into fewer deblurred image pixels. This effect helps balance the image quality within the image.

[0032] In an alternative embodiment of the present invention, the optical system is a projection system instead of an imager. In this case, miniaturization is defined by the ratio between the total track length and the diameter of the object in the plane of the target. According to the present invention, it is also possible to selectively use distortion to achieve a smaller miniaturization ratio.

[0033] All of the above figures and examples depict a miniature mobile phone lens with appropriate distortion. In all of these examples, the imager, camera, or lens can have any field of view, from very narrow to extremely wide. These examples are not intended to be an exhaustive list or to limit the scope and spirit of the present invention. Those skilled in the art will appreciate that changes may be made to the embodiments described above without departing from the broad inventive concept. It is therefore to be understood that this invention is not limited to the disclosed embodiments, but is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

[1] A method for generating a processed image with a target resolution using an imaging device (1130) comprising an imager (1120) and a processing unit (1150), the imager (1120) comprising a miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) and an image sensor, the method comprising: a. Creating an optical image of a scene in an image plane (530, 730) using the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728), the optical image having an original resolution curve (610, 810), a resolution curve representing the resolution as a function of the field of view angle; b. converting the optical image by the image sensor into an original digital image file with the original resolution curve (610, 810); c. receiving the original digital image file, information about the original resolution curve (610, 810) and information about a target resolution curve (620, 820) by the processing unit (1150); and d. Processing the original digital image file by the processing unit (1150) to generate a processed image (1170), wherein the processing unit (1150) transforms the original resolution curve (610, 810) into the target resolution curve (620, 820); wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) has a miniaturization ratio defined as a ratio between a total track length and an image field diameter (560, 760).is defined, wherein the total track length is defined as the distance either from the object-side vertex of the first optical element (512, 712) or the aperture (510, 710), whichever is further away on the object side, to the image plane (530, 730), wherein the image section diameter is represented by the distance between the points (537, 538, 737, 738) on the image plane (530, 730) at which the rays (507, 508, 707, 708) defining half the field of view of the objective impinge on the image plane (530, 730), wherein the miniaturization ratio is less than 0.8, and wherein the original resolution curve (610, 810) has a value that is at least 10% smaller than a corresponding value of the target resolution curve (620, 820) in a center of a field of vision. [2] The method of claim 1, further comprising: e. Outputting the processed image (1170) by the processing unit (1150). [3] The method of claim 1, wherein the original resolution curve (610, 810) and the target resolution curve (620, 820) have at least one point of equal resolution (630, 830), the point of equal resolution (630, 830) separating a compressed zone from an extended zone, the extended zone having at least one point of maximum resolution deviation where the original resolution value is at least 10% higher than the target resolution value. [4] The method of claim 1, wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) is an optical lens consisting of a combination of a plurality of optical elements, each optical element being made of a glass, plastic or crystal material. [5] The method of claim 1, wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) is a wide-angle system with a total field of view of more than 60°. [6] The method of claim 1, wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) comprises at least one freeform optical element. [7] The method of claim 1, wherein the imager (1120) comprises a plurality of optical systems, each of the optical systems producing a separate image. [8] The method of claim 1, wherein the transformation of the original resolution curve (610, 810) into the target resolution curve (620, 820) reduces the difference in image quality of the processed image (1170). [9] The method of claim 1, wherein the target resolution curve (620, 820) is adjusted using at least one external parameter, a user intent, or a sensor output. [10] A method for generating a processed image with a target resolution using an imaging device (1130) comprising an imager (1120) and a processing unit (1150), the imager (1120) comprising a miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) and an image sensor, the method comprising: a. Creating an optical image of a scene in an image plane (530, 730) using the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728), the optical image having an original resolution curve (610, 810), a resolution curve representing the resolution as a function of the field of view angle; b. converting the optical image into an original digital image file (1140) having an intermediate resolution curve by rectifying with the image sensor; c. receiving the original digital image file (1140), information about the intermediate resolution curve and information about the target resolution curve (620, 820) by the processing unit (1150); and d. Processing the original digital image file (1140) by the processing unit (1150) to generate a processed image (1170), wherein the processing unit (1150) transforms the intermediate resolution curve into the target resolution curve (620, 820); wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528;710, 712, 714, 716, 718, 720, 722, 724, 726, 728) has a miniaturization ratio defined as the ratio between a total track length and an image section diameter, wherein the total track length is defined as the distance from either the object-side vertex of the first optical element (512, 712) or the diaphragm (510, 710), whichever is further away on the object side, to the image plane (530, 730), wherein the image section diameter is represented by the distance between the points (537, 538, 737, 738) on the image plane (530, 730) at which the rays (507, 508, 707, 708), which define half the field of view of the objective, strike the image plane (530, 730), and wherein the miniaturization ratio is less than 0.8, and wherein the original resolution curve (610, 810) has a value that is at least 10% smaller than a corresponding value of the target resolution curve (620, 820) in a center of a field of view.; [11] The method of claim 10, further comprising: e. Outputting the processed image by the processing unit (1150). [12] The method of claim 10, wherein the original resolution curve (610, 810) and the target resolution curve (620, 820) have at least one point of equal resolution, the point of equal resolution separating a compressed zone from an extended zone, the extended zone having at least one point of maximum resolution deviation where the original resolution value is at least 10% higher than the target resolution value. [13] The method of claim 10, wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) is an optical lens consisting of a combination of a plurality of optical elements, each optical element being made of a glass, plastic or crystal material. [14] The method of claim 10, wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) is a wide-angle system with a total field of view of more than 60°. [15] The method of claim 10, wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) comprises at least one freeform optical element. [16] The method of claim 10, wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) comprises a non-uniform light transmitter. [17] The method of claim 10, wherein the transformation of the original resolution curve (610, 810) into the target resolution curve (620, 820) reduces the difference in image quality of the processed image. [18] The method of claim 10, wherein the target resolution curve (620, 820) is adjusted using at least one external parameter, a user intent, or a sensor output. [19] The method of claim 10, wherein the intermediate resolution curve is equal to the target resolution curve (620, 820). [20] An imaging device (1130) for creating a processed image having a target resolution, the imaging device (1130) comprising: a. an imager (1120) comprising: i. a miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528; 710, 712, 714, 716, 718, 720, 722, 724, 726, 728) configured to produce an optical image of a scene in an image plane (530, 730), the optical image having an original resolution curve (610, 810), a resolution curve representing the resolution as a function of the field of view angle, and ii. an image sensor configured to convert the optical image into an original digital image file having an original resolution curve (610, 810); and b. a processor configured to: i. Receiving the original digital image file, information about the original resolution curve (610, 810) and information about the target resolution curve (620, 820), and ii. processing the original digital image file to create a processed image by transforming the original resolution curve (610, 810) into the target resolution curve (620, 820), wherein the miniature optical system (510, 512, 514, 516, 518, 520, 522, 524, 526, 528;710, 712, 714, 716, 718, 720, 722, 724, 726, 728) has a miniaturization ratio defined as the ratio between a total track length and an image section diameter, wherein the total track length is defined as the distance from either the object-side vertex of the first optical element (512, 712) or the diaphragm (510, 710), whichever is further away on the object side, to the image plane (530, 730), wherein the image section diameter is represented by the distance between the points (537, 538, 737, 738) on the image plane (530, 730) at which the rays (507, 508, 707, 708), which define half the field of view of the objective, strike the image plane (530, 730), and wherein the miniaturization ratio is less than 0.8, and wherein the original resolution curve (610, 810) has a value that is at least 10% smaller than a corresponding value of a target resolution curve (620, 820) in a center of a field of view;

Images