Spectral camera

Abstract

An imaging system (10) for creating a color image from a plurality of acquisitions includes a first optical path (60) having a first field of view. The first light path (60) has an input coupling element ICE (20) and an output coupling element OCE (40), the input coupling element ICE (20) being designed to at least partially deflect light incident on the input coupling element ICE (20) from the first field of view to the output coupling element OCE (40). Furthermore, the outcoupling element OCE (40) is designed to at least partially outcouple the deflected light, and the incoupling element ICE (20) and / or the outcoupling element OCE (40) are / is designed to at least partially spectrally separate the light from the first field of view. The imaging system (10) further includes a second optical path (70) having a second field of view and including an entrance opening.

Description

1. Technical Field The present invention relates to an imaging system having an input coupling element and an output coupling element, particularly for creating a color image, wherein the input coupling element and / or the output coupling element are configured to perform spectral separation of light.

[0002] 2. Existing Technology Diffractive optical elements (such as gratings or holograms) are preferably used to deflect light incident on an input coupling element ICE (e.g., within a waveguide) to an output coupling element OCE. This, for example, allows for the creation of custom imaging systems.

[0003] In this context, diffractive optical elements can exhibit angle dependence in the spectral distribution of the deflected light. Therefore, if diffractive ICEs and / or OCEs are used in an imaging system to collect, deflect, and / or output couple light, in some cases, true-color imaging of the imaging system may only be achieved within a small area of ​​the field of view (FOV) that is theoretically available to the diffractive element. For incident angles of light outside this range of the FOV, angle-dependent blue or red shifts may exist. Diffractive optical elements typically have an FOV that encompasses a solid angle range within which incident light can be received and / or deflected by the optical element. Essentially, this may perform well at a single wavelength. For example, a monochromatic hologram is configured to deflect light at a specific angle when light of a specific wavelength is incident from a predetermined direction (e.g., along the center of the FOV). However, if the incident angle of the light deviates from the predetermined direction, an example of a hologram may cause a color different from the actual color for which the hologram was designed to be deflected along the predetermined direction. If such diffractive elements are used in an imaging system, unwanted spectral angle dependence may occur: depending on the angle, only a portion of the complete spectrum may be imaged, resulting in gaps in the spectral range. Therefore, colors different from the desired colors may be imaged in the image representation. In RGB optics, this effect may result in a white light image representation or the complete spectrum within a portion of the field of view (FOV), while redshift or blueshift may occur at the edges of the FOV.

[0004] Therefore, the problem solved by the present invention is to at least partially improve the corresponding imaging system and associated method. 3. Summary of the Invention This problem is addressed, at least in part, through the aspects described in this article.

[0006] A first aspect relates to an imaging system for creating a color image from multiple acquisitions, wherein the imaging system includes: a first optical path having a first field of view, the first optical path including: an input coupling element ICE and an output coupling element OCE. The ICE can be configured to at least partially deflect light incident on the ICE from the first field of view of the ICE to the OCE. The OCE can be configured to at least partially output the coupled deflected light, wherein the ICE and / or the OCE are configured to at least partially perform spectral separation on the light from the first field of view. The imaging system may further include a second optical path having a second field of view and including an incident aperture.

[0007] The following text will be based on Figures 1a to 2b This invention explains the general principles upon which it is based and the inventor's insights.

[0008] Figures 1a to 1c This relates to an exemplary imaging system 10 having an ICE 20 and an output coupling element OCE 40, and is used to explain potential problems. Figures 1a to 1c The first optical path of the imaging system is shown.

[0009] Figure 1a An imaging system 10, having an ICE 20 and an OCE 40, is schematically shown in the xz plane. The imaging system 10 also includes a waveguide 30 and a detection system 50, the waveguide having a cross-section in the xz plane that is elongated in the z-direction. The detection system may include, for example, a sensor and a lens. Typically, the sensor 50, as described herein, may optionally be provided with lenses and / or other optical units for creating an image representation, wherein, for example, the lenses and / or other optical units may be configured to cause light and / or other light coupled from the OCE output to be incident on the sensor 50. For example, the ICE 20 is located at the upper end of the waveguide 30 and to the left of the waveguide 30, and, for example, the OCE 40 is located at the lower end of the waveguide 30 and to the right of the waveguide 30.

[0010] ICE 20 has a vertical field of view (v-FOV). Light incident from the v-FOV is deflected by ICE 20 into waveguide 30, as schematically shown by the black arrows. Within the waveguide, the deflected light reaches OCE 40 via total internal reflection. In other exemplary embodiments, for example, light may reach OCE 40 after undergoing more, less, or even no reflection within waveguide 30. ICE 20, waveguide 30, and OCE 40 are matched to each other in their respective shapes, extents, relative positions, and / or relative orientations such that the deflected light from ICE 20 reaches OCE 40 as efficiently as possible, and the deflected light is at least partially output from OCE and coupled to detection system 50, as schematically shown by the black arrows.

[0011] v-FOV includes maximum single-sided field of view α v In some examples, the maximum unilateral field of view can be at least 30°, at least 45°, or at least 60° and / or less than 90° or less than 80° (the entire vertical field of view of the FOV (in the case of a symmetrical FOV) will be twice this angle, such as...). Figure 1a (As shown). In Figure 1a In the example, α v = 0 corresponds to light incident perpendicular to the surface of waveguide 30.

[0012] In principle, the deflection of light by ICE 20 and OCE 40 can depend on the incident angle of the incident light, for example, the degree of which is such that the deflection angle of the deflected light and / or the spectral distribution depends on the incident angle and / or only a portion of the light reaches OCE 40.

[0013] Figure 1b Schematally shown in the xy plane Figure 1a The cross-sectional view of the imaging system 10 allows for the display of the horizontal field of view (h-FOV) of the ICE 10. According to Figure 1b The horizontal input coupling to ICE 20 and the horizontal output coupling from OCE 40 to detection system 50 are evident, while Figure 1a The vertical component is best described.

[0014] Figure 1c Schematally shown in the yz plane Figure 1a and Figure 1b A cross-sectional view of the imaging system 10. It is evident that the ICE 20 is elongated in one direction (along the y-axis in this example) and has a shorter length in the plane of the waveguide 30 in a direction perpendicular to that direction (along the z-axis in this example). The elongated rectangular cross-section of the ICE defines the region where light incident on the ICE 20 is at least partially deflected within the waveguide 30. Since the area of ​​the OCE 40 in the plane of the waveguide 30 is generally smaller than that of the ICE 20, all paths along which light is deflected from the ICE 20 to the OCE 40 extend in the projection of the light onto the yz plane within a light gray trapezoidal region between the ICE 20 and the OCE 40. Light extending at least partially outside this trapezoid does not originate from the ICE 20 and / or does not occur on the OCE 40, and therefore does not play a decisive role in the imaging of the imaging system 10.

[0015] Spectral angle dependence has been observed in such imaging systems, and is described below by way of example: Figure 2a This shows the incident angle θ of the light from the first field of view in the first optical path of the imaging system (in... Figure 2aThe example shows the output coupling wavelength spectrum within this field of view, varying from -30° to +30°. The intensity distribution shown corresponds to the first-order diffraction of the first optical path. For illustrative purposes, one example is emphasized: at an angle of -10°, the imaging system outputs light coupled within a spectral region of approximately 560 nm. Therefore, firstly, the imaging system outputs coupled light with different spectral ranges for different incident angles. Secondly, different incident angles are imaged onto different locations within the detection system 50.

[0016] from Figure 2a It is evident that the angle of the coupled light output by the imaging system (specifically the first optical path) increases monotonically with wavelength. Therefore, the angle can be uniquely assigned to the chromatogram. Furthermore, Figure 2a The gradient in the image increases with increasing wavelength. This article references... Figures 8a to 9b This relationship is described in detail. Furthermore, the angular width of the output coupling wavelength increases with increasing wavelength, and conversely, the spectral width increases with increasing angle. Depending on the thickness of the ICE and / or OCE in the imaging system, the curve has a certain width or selectivity. The inventors have recognized that the output coupling spectrum can be used to create color images, as explained in more detail below. In particular, the output coupling spectrum can be matched to the requirements of a specific application, for example, by designing the ICE and / or OCE (e.g., by varying their thickness). This is due to the fact that, for example, in the case of an ICE and / or OCE with a volumetric hologram as the first optical path, more holographic planes can be written into the ICE and / or OCE as the thickness increases. With the increase in the number of such holographic layers (which can represent Bragg planes), the light incident on the ICE and / or OCE must satisfy the Bragg condition more frequently. This results in a more stringent (Bragg) condition for deflected light in a thicker ICE or OCE than in a thinner ICE or OCE. Therefore, the selectivity of the deflected light (i.e., spectral sharpness) increases with increasing ICE and / or OCE thickness or the consequent increase in the number of Bragg planes in the ICE and / or OCE.

[0017] Figure 2b The ICE 20 is shown in the xz plane, and the incident angle θ (in the xz plane) of the selected representative wavelengths of 440 nm, 530 nm, 610 nm, 670 nm, and 710 nm is schematically shown in an exemplary imaging system with the ICE 20 and corresponding OCEs (not shown here) coupled to the corresponding wavelengths. Figure 2b In the example, the range is -30° to +30°. Therefore... Figure 2b Corresponding to Figure 2a A spatial diagram depicting the content of the mid-spectral spectrum. From Figure 2bIt is evident that the imaging system inputs and couples light of different wavelengths for different regions of the first field of view. If light other than the wavelength that is most efficiently input and coupled is incident on the ICE 20 at a given angle, that wavelength may, for example, be deflected but not reach, for example, the associated OCE and thus be lost, or it may ultimately not be output coupled from the associated OCE.

[0018] about Figures 1a to 1c The imaging system 10 implies that each region of the field of view can be assigned a preferred wavelength, which can be ideally coupled to the input and / or output, while deviating wavelengths are not coupled to the input and / or output, or are only poorly coupled. Therefore, a single acquisition of the field of view cannot provide an image representation of the desired colors. This can often lead to situations where objects cannot be imaged at all. For example, a pure red object located in a region of the field of view where only blue light can be well coupled to the input and / or output may not be imaged at all. Thus, spectral angle dependence often presents a problem that is difficult to avoid. Other systems employ various measures to reduce and / or compensate for such spectral angle dependence of deflected light.

[0019] However, contrary to all previously known efforts, the inventors of this invention have recognized that it is precisely this spectral angle dependence of the deflected light that can be advantageously utilized: in this invention, since the second optical path can be used for acquisition reference, a color image can be created or assembled from multiple acquisitions of the first optical path. Therefore, an object region can be acquired from multiple angles via the first path, for example, by tilting and / or shifting, and thus color information from different wavelengths (e.g., red, green, and blue (or other and / or additional colors)) can be acquired for that object region. Since a reference image (e.g., a grayscale image) can be acquired via the second optical path, relative positional information between the images of the first optical path can be obtained, and this information is used to allow the combination of the first optical path images to create a color image. The positional information (e.g., angle information) is related to the angle of the input and / or output coupled with a specific wavelength, corresponding to... Figure 2a and Figure 2b Knowledge pairing allows for the creation of spectral information for each object region.

[0020] Simple options for acquiring data from different angles include manually moving (e.g., tilting and / or moving) the imaging system and / or the first optical path. This can be easily achieved, for example, by mounting such an imaging system in a handheld device (such as a cellular phone).

[0021] Therefore, this system offers the following advantages in particular: Instead of building up significantly reduced color information (e.g., RGB), as is typical for RGB sensors, this allows for the creation of high-spectral-resolution images from acquisitions, for example, from more than three angles. For instance, if acquisitions are performed from multiple angles, differing from each other only slightly, a quasi-continuous spectrum can be determined for each image region, and thus complete color information can be obtained, not just three discrete values ​​for red, green, and blue. As a result of analyzing the acquired spectra, this opens up new areas of application.

[0022] In addition, color sensitivity is obtained by the angle of incidence (e.g., see...). Figure 2a and Figure 2b (and its description). Therefore, bulky, expensive, and labor-intensive components, such as color filters, RGB sensors, and solutions consisting of hyperspectral cameras, can be eliminated. Filter-based solutions require a set of predefined filters, for example, in front of a CMOS chip, to make statements related to the spectral range. Other solutions require more installation space; for example, at least multiple CMOS chips and associated optics must be installed in, for example, a smartphone, to analyze the item to be inspected using relevant spectral information. Hyperspectral cameras also require more installation space. In contrast, a simple intensity sensor can be used in this invention. This saves cost and installation space. Compared to a typical RGB sensor (where each pixel is divided into four color pixels (1x red, 2x green, 1x blue), thus each color can only use a quarter or half of the sensor area), the solution according to the invention always allows the entire area to be usable and / or allows for improved resolution. Therefore, lower light intensities can also be detected in certain embodiments, and this can be advantageous, for example, in the case of dark images (e.g., at night).

[0023] The components of an imaging system should be understood as follows: The ICE and OCE are configured as described herein and can diffract or deflect and / or refract (focus and / or scatter) light. The ICE and OCE can be matched to each other and, for example, to the requirements of a particular application in terms of their absolute and / or relative size, location, and / or orientation. For example, the ICE can be a diffractive ICE. For example, the OCE can be a diffractive OCE. An ICE can, for example, include multiple sub-ICEs, and / or an OCE can, for example, include multiple sub-OCEs. Sub-ICEs and / or sub-OCEs can have the characteristics described herein with respect to ICEs and / or OCEs.

[0024] An ICE and / or OCE configured to at least partially separate the light from a first field of view can cause [the following]: Figure 2a and Figure 2bThe described spectral separation is similar to spectral splitting. Essentially, this allows wavelengths to be assigned to the output-coupled light based on the direction of the light coupled by the OCE output. For example, if the spectrally split light is then coupled to an optical sensor by the output, wavelength / color can be assigned to each pixel of the optical sensor.

[0025] The entrance aperture may include one or more pupils and / or stops, and / or lens elements (and / or other refractive optics) of fixed and / or variable size (e.g., radius in the example of a circular entrance aperture).

[0026] The first field of view should be understood as follows: In principle, the ICE is capable of deflecting light incident on the ICE. Depending on the configuration of the first optical path (e.g., as described herein with respect to the size, location, and / or orientation of the ICE and / or OCE), light from different angles can be deflected from the ICE to the OCE. The first field of view includes those angles (view angles) at which light incident on the ICE is deflected to the OCE relative to the incident normal of the ICE. The amount of light then output from the OCE and coupled to optional optical sensors or other detection components is independent of those angles. In this case, the incident normal can be defined, for example, by an axis perpendicular to the ICE and intersecting the ICE at its geometric centroid.

[0027] The second field of view is the field of view of the second optical path, which can be configured to be substantially similar to the field of view of a conventional camera. Therefore, the second field of view includes those angles (fields of view) where light incident through the incident aperture can pass through the incident aperture and, in particular, is not absorbed or scattered.

[0028] In an exemplary embodiment, the imaging system may further include an optical sensor, preferably a light intensity sensor, wherein the first optical path and / or the second optical path may be configured to cause at least some of the light from the first field of view and / or the second field of view to be incident on the optical sensor.

[0029] As described in this article, imaging systems enable the utilization of various advantages associated with optical sensors, as explained above.

[0030] In particular, if the same optical sensor is used for, for example, the first and second optical paths, further savings can be achieved in terms of space, cost, and / or assembly and maintenance expenses.

[0031] Optical sensors may include electronic components such as photodetectors, light sensors, optical detectors, and / or photoelectric sensors. In principle, optical sensors are capable of converting light into electrical signals, for example, by utilizing the photoelectric effect, and / or of acquiring and / or reading resistance values ​​that depend on incident radiation. In this document, "light" and / or "optical" may, in principle, include not only visible wavelengths but also invisible infrared light and / or ultraviolet radiation.

[0032] Optical sensors can represent suitable components that are directly matched to an imaging system and allow for the digital recording of the image representation created by the imaging system.

[0033] For example, the imaging system may also include components for determining the relative positional information between a first image and a second image in a first field of view acquired by an optical sensor.

[0034] The first and second fields of view can overlap. In some examples, their overlap with the other field of view can be greater than 50%, or even substantially the same.

[0035] In the example, the components used to determine relative position information may be determined at least in part based on multiple acquisitions of the second field of view, preferably by edge detection and / or by comparison between at least two acquisitions of the multiple acquisitions of the second field of view.

[0036] For example, if a second optical path is used to acquire associated second optical path (grayscale) images for each image acquisition of the first field of view (where the positions of the imaging systems are substantially the same), and these second optical path (grayscale) images are optionally recorded using the same optical sensor, then these (grayscale) images can contain positional information and allow combining images of the first field of view at different positions to obtain a color image. For example, the acquisition of (grayscale images) can be used to determine relative positional information between two images of the second field of view described herein. For example, digital image analysis methods can be used for this purpose. Consequently, positional information between corresponding images of the first field of view can then be determined.

[0037] This concept can be based on, for example Figure 2e To explain. The figure schematically shows sensor 50, for example, which has three pixels 51, 52, and 53; therefore, the sensor is capable of resolving three image regions (this small number is chosen here only for clarity, and it goes without saying that some embodiments can provide a significantly larger number of pixels in 2D, such as at least 100 × 100 or at least 1000 × 1000). This can be based on the acquisition of the first field of view FOV-1 at different angles γ1, γ2, γ3, γ4, and γ5. And the positional information between acquisitions to create a color image 80: Figure 2eIn this sensor, ICE 20 and OCE are configured such that blue light from a first angle in the first field of view is incident on pixel 53 of sensor 50, green light from a second angle in the first field of view is incident on pixel 52 of sensor 50, and red light from a third angle in the first field of view is incident on pixel 51 of sensor 50. Therefore, each pixel 51, 52, 53 can be assigned a color or wavelength. This concept can be applied to 2D sensors and / or sensors with any number of pixels.

[0038] If in Figure 2e The examples are for illustrative purposes and are presented from five different angles (similar to...). Figure 2b The example mentioned above (using angles γ1, γ2, γ3, γ4, γ5) captures images of a person (with three object regions: head, upper body, and lower body), creating five images (80). Each image contains color information associated with a different object region. For example, if three exemplary object regions are each captured three times at corresponding angles where red, green, and blue light are incident on the optical sensor 50, an image 80 can be obtained in principle. RGB color information for all three object regions: For an image acquired at angle γ1, only the first object region (specifically, the head of a person) is within the first field of view. Only red light is imaged from the first object region. Therefore, this image contains red information associated with the first object region. The second and third object regions (the lower and upper bodies of the person) are outside the first field of view, as indicated by the gray shading lines.

[0039] For an image acquired at angle γ2, two object regions (specifically, the head (first object region) and upper body (second object region)) are located within the first field of view. Only green light is imaged from the first object region, and only red light is imaged from the second object region. Therefore, this image contains red information associated with the second object region and green information associated with the first object region. The third object region (the lower body) is outside the first field of view, as indicated by the gray shading.

[0040] For an image acquired at angle γ3, all three object regions (specifically, the head (first object region), upper body (second object region), and lower body (third object region)) are located within the first field of view. Only blue light is imaged from the first object region, only green light from the second object region, and only red light from the third object region. Therefore, this image contains red information associated with the third object region, green information associated with the second object region, and blue information associated with the first object region.

[0041] For an image acquired at angle γ4, two object regions (specifically, the upper body of a person (the second object region) and the lower body (the third object region)) are located within the first field of view. Only blue light is imaged from the second object region, and only green light is imaged from the third object region. Therefore, this image contains green information associated with the third object region and blue information associated with the second object region. The first object region (the person's head) is outside the first field of view, as indicated by the gray shading.

[0042] For the image acquired at angle γ5, only the third object region (specifically, the lower body of the person) is within the first field of view. Only blue light is imaged from the first object region. Therefore, this image contains blue information associated with the third object region. The first and second object regions (the person's head and upper body) are outside the first field of view, as indicated by the gray shading.

[0043] Therefore, five images 80 were created for the first field of view. Furthermore, in principle, these images contain RGB information for all three object regions. If we now use the image of the first field of view (80...) The relative positional information between them can be at least partially based on image 80. And relative position information to create a color image 80, such as Figure 2e The vertical alignment of the image of the person under reference numeral 80 in the attached figure is schematically shown. The relative positional information allows for the determination of image 80. For example, it's necessary to determine how to connect and / or how to make them overlap in order to correctly create the color image 80. Essentially, what's important for the creation of the color image 80 is that the object region imaged onto the sensor pixels (or multiple sensor pixels in other examples) assigned to the first color (or spectral band) during the first acquisition of the first field of view is imaged onto the sensor pixels (or multiple sensor pixels in other examples) assigned to the second color (or second spectral band) during the second acquisition of the first field of view, and so on. Therefore, with each acquisition of the first field of view, more color information about the object region can be obtained.

[0044] Therefore, the component used to determine the relative positional information between the first image and the second image of the first field of view recorded by the optical sensor offers the advantage that this positional information can be determined during acquisition, and thus can advantageously facilitate the creation of a color image.

[0045] For example, the component can be configured to determine relative position information based on images of the second field of view, for example by determining how the images of the second field of view are related to each other using methods such as edge detection and / or image matching, and thus, corresponding references to the correspondingly associated images of the first field of view can also be established and / or ways in which the images of the first field of view can be connected to each other (e.g. Figure 2e (Illustrative depiction).

[0046] For example, relative position information may include the spatial position between the imaging system and the object to be imaged (e.g., the angle at which light from the selected object region reaches the ICE relative to the incident normal of the ICE, the distance between the selected object region and the ICE and / or any other element of the imaging system, the displacement of the selected object region in a plane perpendicular to the incident normal of the ICE, and / or other position indicators). Importantly, the relative position of the images in the second field of view relative to each other can be determined, and therefore the relative position of the associated images in the first field of view can be determined.

[0047] For example, the determining component can be configured to determine its position based at least in part on data from a position sensor and / or from an acceleration sensor.

[0048] This location data can be used, for example, to supplement image-based determination of location information based on a second field of view, and can improve the accuracy of location information and thus improve image quality.

[0049] In an exemplary embodiment, the imaging system may further include tools for stabilizing the optical sensor, wherein the stabilizing tools preferably include tools for translation and / or tools for rotation about at least one axis, particularly preferably a gimbal mount. This can, for example, facilitate the determination of positional information and thus improve image quality.

[0050] For example, the ICE and / or OCE can be configured to at least partially separate the light from the first field of view in such a way that at least one region of the optical sensor can be assigned predetermined color information.

[0051] Information about the allocation between regions of an optical sensor and their corresponding color information can be stored in the form of functions and / or tables on, for example, an imaging system and / or an (external) server. These functions and / or tables can be accessed for, for example, to create color images.

[0052] Therefore, the process of creating color images can become more robust, simpler, and / or faster.

[0053] For example, the imaging system may also include tools for reversibly switching between the first optical path and the second optical path.

[0054] This is advantageous because, for example, only one optical path can guide light to, for example, a shared sensor at any given time, and images can be acquired, stored, and / or evaluated individually.

[0055] Reversible switching between the first and second optical paths involves simultaneously and / or time-independently opening and / or blocking the first and second optical paths.

[0056] If the path is blocked, light from the field of view of that path cannot reach the optical sensor, or only a small amount of light can travel along the optical path. If the path is open, light from the field of view of that path (which in any case is more than in the blocked state) can travel along the optical path to the optical sensor.

[0057] In one example, the tool for reversible switching may include at least one electrochromic layer.

[0058] The electrochromic layer is composed of materials whose light transmittance varies according to an applied (DC) voltage, for example, because the material utilizes the ability of molecules and crystals (e.g., due to a localized external electric field that can affect the electronic state) to alter its optical properties. The layer (typically, for example, microscopically thin) may contain tungsten oxide and / or polyaniline and / or have a thickness between 0.1 μm and 10 μm. The layer can be activated, for example, by a weak current, and thus, for example, change its color. If the polarity of the voltage changes, the layer can revert to a colorless state or become more or less transparent.

[0059] Therefore, in the context of this invention, an electrochromic layer represents a suitable tool for providing space savings and / or a well-controlled tool for reversibly switching between a first optical path and a second optical path.

[0060] For example, the tool for reversible switching can be configured to periodically switch between the first optical path and the second optical path at a frequency greater than 10 Hz.

[0061] Therefore, for example, a corresponding pair of images of a location can be acquired (in a highly automated manner), wherein the image pair may include, for example, an image of a first field of view and an image of a second field of view at a given location. In some examples, the user can move the imaging system (e.g., translate it along a straight line, as in the case of a scanner; or rotate it, for example, with a rotation component about a rotation axis that extends perpendicular to the optical axis of the first field of view of the first optical path).

[0062] In addition, the imaging system may include tools for automatically changing (e.g., tilting) the first field of view.

[0063] This allows for, for example, automatic scanning of the area to be imaged, and furthermore, relative positional information can be determined based on the settings of the tool used for automatic tilting; this can be more accurate than other methods used to determine relative positional information. Therefore, image quality can be further improved in this way. Furthermore, the user does not need to manually tilt and / or shift the first field of view, which improves user comfort and thus, for example, increases user satisfaction.

[0064] To achieve this, the tool for automatically tilting the first field of view may include, for example, a tool for rotating about at least one axis, preferably a gimbal mount.

[0065] These embodiments are particularly well-suited to enable the tilting of the first field of view with high precision, without requiring the user to actively translate / move the imaging system.

[0066] In one example, the imaging system can also be configured to create a color image based at least in part on at least two images of a first field of view and relative position information between the first and second images of the first field of view acquired by an optical sensor.

[0067] For example, relative position information can be measured by the relative displacement and / or tilt of two first and / or second fields of view. Based on this, for instance, the average displacement vector of grayscale images acquired sequentially and / or the displacement vector of one or more image regions and / or image pixels can be determined. Imaging conditions may change due to the aforementioned tilt of the beam path, and this can lead to image artifacts known as distortion. Therefore, determining the displacement vector of individual pixels (preferably (almost) all pixels) may be preferred. However, since this could require significant storage capacity and / or computation time, it is more likely that the displacement vectors of only a few image regions will be determined.

[0068] To this end, standard image processing methods can be used to find corresponding points in multiple images. These methods can include, for example, approaches based on "optical flow": the optical flow of an image sequence is a vector field (corresponding to displacement vectors and / or relative position information) projected onto the image plane by the velocity of visible points in object space within the reference frame of the imaging optics. In image processing, optical flow represents relative position information. Advantageous alternatives include, for example, RANSAC ("Random Sample Consensus") methods, which can be particularly robust in estimating relative position information based on correspondences with random samples.

[0069] Alternatively, or in alternatives, measures such as segmentation based on color and texture or point assignment to objects can be used to determine the relative positional information of individual pixels and / or image regions, for example, in the form of displacement vectors as described herein. Furthermore, for example, two or more spectral images can be combined based at least in part on the relative positional information; for example, the combination may also include relative displacement, size-based cropping, distortion compensation, compression, and / or stretching.

[0070] In some examples, the ICE and / or OCE may include holographic optical elements, preferably RGB holograms, volumetric holograms, and / or relief holograms.

[0071] Holograms (e.g., volumetric holograms) can be described with high selectivity, and this can, for example, improve image quality. Embossed holograms can be written, engraved, and / or pressed into the surface of a waveguide, and therefore can be even more space-efficient than, for example, volumetric holograms.

[0072] In the context of this invention, holographic optical elements (such as RGB holograms, volumetric holograms, and / or relief holograms) can be exposed according to known methods to determine the light deflection characteristics of the ICE and / or OCE according to system requirements. In the case of the ICE, it should be advantageously noted that higher-order diffractions that may exist (e.g., in the case of relief holograms) do not randomly or unintentionally diffract different colors of light to the same angles as the first-order diffraction of the ICE. Otherwise, spectral separation over the angular range of the ICE may be lost. Typically, this can be achieved by so-called blazed gratings. Volumetric holograms are not affected by this problem because they typically have only one diffraction order.

[0073] For example, the ICE and / or OCE may include reflective optical non-diffractive elements. For instance, the ICE may include an optically non-diffractive reflective inner surface. In principle, this can be an advantageous and simple option, saving cost and space and, in addition, enabling, for example, the deflection of a larger proportion of the incident light, which can, for example, improve acquisition in low light intensity conditions. However, at least one of the ICE and OCE elements is configured to perform spectral separation of the light (e.g., for this purpose, the ICE and / or OCE include diffraction gratings, holograms, and / or prisms, etc.) in order to obtain the spectral information used herein.

[0074] In another example, the imaging system may also include a waveguide.

[0075] While waveguides have many possible configurations, in some applications they may be implemented, for example, as one or more window panes, or integrated into one or more window panes. Examples of multiple window panes may include, for example, laminated glass, which may comprise at least two glass panes that can be connected to each other, in their respective cases, by, for example, an interlayer made of, for example, plastic, casting resin, and / or a composite film. For example, light incident on the waveguide (e.g., the window pane) at a first location can thus be guided internally via the waveguide to another second location on the waveguide (e.g., the window pane), from which the light can then be redirected to, for example, a camera and / or an image sensor. Therefore, for example, the camera may be positioned at a location different from the first location, and at that location, the camera is, for example, not visible from the outside.

[0076] A waveguide can represent an advantageous option for securing an ICE and an OCE in their relative positions to each other in a reliable, space-saving, and cost-effective manner. A waveguide can be, for example, at least partially composed of glass and / or polymers, and / or can be matched to a particular application in terms of its shape, extent, surface quality, material composition, and / or (spectrally related) transparency / light transmittance. Such applications can be, for example, integrating an imaging system into a screen (wherein the waveguide can be, for example, part of a computer screen, part of a clock face / screen, and / or part of a cellular phone), integrating it into a window (wherein the waveguide can be, for example, part of a windshield and / or any other window glass in a vehicle, and / or part of a window in a building, and / or part of a display), and / or integrating it into eyeglasses (wherein the waveguide can be, for example, part of a lens).

[0077] In some examples, the ICE can be configured to couple at least some of the light incident on the ICE (preferably at least two wavelengths) from the first field-of-view input of the ICE into the waveguide.

[0078] Input coupling to a waveguide offers the following advantages: in particular, it allows the transmission of light using the same element (waveguide) that defines the stability and basic geometry of the system, thus providing an efficient, space-saving, and cost-effective solution. In this case, the input-coupled light can be deflected, for example, as explained below.

[0079] Specifically, in an exemplary embodiment, the ICE can be configured to deflect at least some of the light incident on the ICE from the first field of view to the OCE via total internal reflection in the waveguide.

[0080] In this case, the angle between the light deflected by the ICE and the surface of the waveguide can be set, for example, by the exposure of the ICE and / or by the relative attachment or positioning on the waveguide, so that the deflected light reaches the OCE by total internal reflection, and this can result in no light intensity loss, negligible light intensity loss and / or only small light intensity loss in the waveguide.

[0081] In some examples, the OCE can be configured to couple at least some of the deflected light outputs from at least two wavelengths of deflected light out of the waveguide.

[0082] In an exemplary embodiment, the surface area of ​​the OCE may be smaller than that of the ICE.

[0083] This relative size ratio is advantageous, particularly given that the size of the ICE influences the size of the first field of view. That is, the larger the ICE, the larger the field of view can theoretically be; this is generally preferred. Similarly, the size of the OCE determines the beam cross-section of the output coupled light. A smaller OCE allows for the selection of smaller apertures for lenses and / or optical sensors and / or detection systems used to acquire images; in principle, this can have a positive impact on image quality. Generally, it is advantageous to find trade-offs between aperture size, waveguide thickness, ICE and / or OCE size, and / or field of view size, in order to optimize the imaging system, for example, in terms of planned image representation, installation space requirements, etc.

[0084] In an exemplary embodiment, the waveguide may include a first surface and a second surface opposite to the first surface, the surfaces preferably being spaced apart from each other by a substantially constant layer thickness.

[0085] Therefore, such waveguides are particularly well-suited for guiding deflected light from the ICE to the OCE in a controlled manner with low loss via total internal reflection, which has a positive impact on the efficiency of the imaging system and the image quality.

[0086] For example, the ICE can be substantially arranged on the first surface of the waveguide, and / or the OCE can be substantially arranged on the second surface of the waveguide.

[0087] If the ICE and OCE are arranged on opposite sides of the waveguide, light can be deflected from the ICE to the OCE without reflection or by means of reflection within the waveguide. Alternatively, the ICE and OCE can be attached to a common surface of the waveguide. Furthermore, the OCE and / or ICE can be at least partially attached inside the waveguide.

[0088] In such an exemplary embodiment, the ICE and OCE can be positioned and oriented relative to each other in the waveguide plane to optimize deflection from the ICE to the OCE. For example, the ICE and OCE can be attached to the surface of the waveguide, integrated into the waveguide, etc. In examples where the ICE and / or OCE include holograms or holographic optical elements, all holograms can be transmission holograms and / or reflection holograms, and can also be embedded in window glass or between two window panes (e.g., laminated glass).

[0089] In one example, the imaging system may also include a lens, wherein the lens may be configured to at least partially influence the light coupled by the OCE output and / or direct the light to an optical sensor as described herein.

[0090] Lenses can compensate for imaging aberrations and thus improve image quality.

[0091] The function of the lens can also be partially integrated into, for example, an OCE, in such a way that the OCE not only deflects light (i.e., modifies the direction of the deflected light so that its output is coupled to the sensor), but also has, for example, focusing and / or diverging functions, so that the OCE, alone or in combination with the lens, applies light to the sensor in a suitable manner.

[0092] On the other hand, it relates to a handheld device, preferably a cellular phone, having an imaging system as described herein.

[0093] Its use in handheld devices such as cellular phones is advantageous, especially because they inherently enable tilting, shifting and / or other modifications of the position of the first field of view, for example, by simple hand movements of the user.

[0094] On the other hand, a method for creating a color image from multiple acquisitions is provided. Here, the method includes acquiring at least a first image and a second image of a first field of view of an imaging system. The first image and the second image may be acquired from a first position and a second position different from the first position, respectively. The imaging system includes: a first optical path having a first field of view. The first optical path includes an input coupling element ICE and an output coupling element OCE, wherein the ICE is configured to at least partially deflect light incident on the ICE from the first field of view of the ICE to the OCE, and the OCE is configured to at least partially output the coupled deflected light. The ICE and / or the OCE are configured to at least partially perform spectral separation on the light from the first field of view. The method further includes storing the first image and the second image, as well as relative positional information between the first image and the second image.

[0095] The corresponding imaging system can be configured to acquire at least a first image and a second image of a first field of view of the imaging system. The imaging system includes a first optical path having a first field of view, and the first optical path includes an input coupling element (ICE) and an output coupling element (OCE). The ICE is configured to at least partially deflect light incident on the ICE from the first field of view to the OCE; the OCE is configured to at least partially output the coupled deflected light; and the ICE and / or the OCE is configured to at least partially perform spectral separation on the light from the first field of view. Furthermore, the corresponding imaging system can be configured to store the first image and the second image, as well as relative positional information between the first image and the second image.

[0096] Another aspect of the invention relates to a method for creating a color image from multiple acquisitions, wherein the method includes acquiring at least a first image and a second image of a first field of view of an imaging system. Acquiring may include (e.g., acquiring and / or receiving images from a memory). Furthermore, the imaging system includes a first optical path having a first field of view, and the first optical path includes an input coupling element ICE and an output coupling element OCE, wherein the ICE is configured to at least partially deflect light incident on the ICE from the first field of view to the OCE, wherein the OCE is configured to at least partially output the coupled deflected light, and wherein the ICE and / or the OCE is configured to at least partially perform spectral separation on the light from the first field of view. The method also includes determining relative positional information between the first image and the second image. For example, the positional information may be determined based on images of the second field of view of the imaging system, which are associated with images of the first field of view (as described herein). These images may also be acquired or received.

[0097] The corresponding imaging system can be configured to acquire at least a first image and a second image of the imaging system's field of view. The imaging system includes a first optical path having a first field of view, and the first optical path includes: an input coupling element (ICE); and an output coupling element (OCE). The ICE is configured to at least partially deflect light incident on the ICE from the first field of view to the OCE. The OCE is configured to at least partially output the coupled deflected light. The ICE and / or the OCE is configured to at least partially perform spectral separation on the light from the first field of view. Furthermore, the corresponding imaging system can be configured to determine relative positional information between the first image and the second image.

[0098] The method may also further include storing the first image and the second image, as well as the relative position information between the determined first image and the second image.

[0099] The method according to the invention may, for example, further include creating a color image based at least in part on a first image and a second image, as well as relative position information.

[0100] These methods are suitable for creating color images or acquiring the necessary data for this purpose. These methods possess the advantages mentioned regarding the imaging systems described herein.

[0101] On the other hand, a method for establishing color information of an object is involved. This method may include the following steps: performing multiple acquisitions of the object using an imaging system as described herein; Color information of the object is extracted from the collected data, preferably through spectral analysis.

[0102] The present invention also includes corresponding uses of the imaging system described herein.

[0103] Color information extraction can be used in many possible application areas: for example, in exemplary everyday scenarios, a photograph of food can provide information about its contents or composition (e.g., by extracting the color information of the photographed food), or a photograph of the photographer's own skin can indicate, for example, whether sunscreen has been fully applied (e.g., by extracting the color information of the photographed skin and / or skin portions). True color measurement or color information extraction using an imaging system can also be used to check makeup or to match clothing and / or furniture colors. Associated procedures can, for example, be configured to provide recommendations in appropriate categories based on color information. In the context of image acquisition, automated measures can, for example, be proposed and / or implemented to improve image color (e.g., regarding color temperature, exposure, and / or white balance). Color recognition can also help identify colors in the health field; this can be particularly advantageous for, for example, people who are at least partially colorblind. In the dental field, for example, the whiteness of teeth can be reliably and quantifiably determined, which can allow inferences about dental health. Generally, the imaging systems described herein are particularly well-suited to support these and other applications due to their high spectral resolution.

[0104] These and other exemplary applications of the imaging system according to the invention can be advantageously made possible by the option of illuminating the object to be imaged in a targeted manner. For example, a system including an imaging system (e.g., a handheld device as described herein) may include a light source and / or may provide an external light source. The light source may include, for example, a flashlight (e.g., the flashlight of a handheld device, such as a cellular phone flashlight), a white light source (e.g., a halogen tungsten lamp, for example, with a color temperature of about 2300 K-2900 K) and / or one or more LEDs of the same and / or different colors. The light source may, for example, include the visible spectral range, the ultraviolet (UV) spectral range, the near-infrared (NIR) spectral range, and / or the infrared spectral range.

[0105] For example, a light source can illuminate the object to be imaged, allowing the object to be imaged in a reflective and / or transmissive manner. In a reflective example, the side of the object at least partially facing the imaging system's ICE can be at least partially exposed to the light source, such that the object reflects light from the light source to the ICE, and the object can be at least partially imaged. Alternatively, the side of the object at least partially facing away from the imaging system's ICE can be at least partially exposed to the light source, such that light from the light source and transmitted through the object reaches the ICE, and the object can be at least partially imaged transmissively.

[0106] In principle, securing the object to be imaged can be helpful for this purpose. This can be achieved, for example, by using an object carrier configured to hold the object in place. However, an object carrier is not necessary. Alternatively, or in addition, a setup can be provided that is configured to hold the object in a predetermined and / or changeable position and / or alignment relative to the imaging system and / or light source, for example, by means of clamps, jigs, etc.

[0107] For example, plant monitoring is an exemplary application that makes this possible. In this context, processes involved in photosynthesis can be observed, for example. Typical absorption bands of interest here are in the range between the UV (>200 nm) spectral range and the NIR spectral range. For this wavelength range, optics and / or collimators for spot illumination are available, and the light source can be equipped with these optics and / or collimators.

[0108] Therefore, these and / or other exemplary functionalities can be created, for example, in cellular phones (e.g., in specialized applications), and / or can be implemented in existing camera applications and can provide capabilities beyond those of existing devices.

[0109] The steps of the methods described herein can also be implemented as functionalities of an imaging system and / or its components, and vice versa. Corresponding computer programs containing instructions for performing the functionalities described herein may also be provided. 4. Description of the attached drawings Figure 1a A schematic view of an imaging system with input coupling elements and output coupling elements is shown in the xz plane.

[0111] Figure 1b A schematic view of an imaging system with input coupling elements and output coupling elements is shown in the xy plane.

[0112] Figure 1c A schematic view of an imaging system with input coupling elements and output coupling elements is shown in the yz plane.

[0113] Figure 2a The output coupled wavelength spectrum within the field of view is shown as the incident angle of light from the imaging system varies.

[0114] Figure 2b The individual wavelengths of 440 nm, 530 nm, 610 nm, 670 nm and 710 nm are schematically shown, with the incident angles of the corresponding wavelengths being input and / or output coupled in the exemplary imaging system.

[0115] Figure 2c The first field of view (shaded line) of the first optical path input coupling element is shown relative to the object to be imaged (divided into grid patches), such that the selected object region forms a first angle with respect to the incident normal of the input coupling element.

[0116] Figure 2d The diagram shows a first field of view (shaded) of the first optical path input coupling element relative to the object to be imaged (divided into grid patches), such that the selected object region forms a second angle with respect to the incident normal of the input coupling element, the second angle being different from... Figure 2c The first angle.

[0117] Figure 2e The illustration schematically shows how a sensor with three pixels can distinguish three image regions and how it can combine positional information to capture the first field of view from different angles to form a color image.

[0118] Figure 3a An exemplary embodiment of an imaging system is shown, the imaging system including a first optical path and a second optical path.

[0119] Figure 3b It shows Figure 3a An imaging system in which a tool for reversibly switching opens a first optical path and blocks a second optical path.

[0120] Figure 3c It shows Figure 3a An imaging system in which a tool for reversibly switching blocks the first optical path and opens the second optical path.

[0121] Figure 4a A schematic view of an imaging system is shown in the xz plane, which has an input coupling element, an output coupling element, and a waveguide with a wedge-shaped cross section.

[0122] Figure 4b A schematic view of an imaging system is shown in the xz plane, which has an input coupling element, an output coupling element, and a waveguide that bends in the xz plane.

[0123] Figure 5aThe superposition of the first and second fields of view in a first orientation of an exemplary imaging system is shown.

[0124] Figure 5b The superposition of the first and second fields of view in a second orientation of an exemplary imaging system is shown, wherein the second orientation is relative to... Figure 5a The first orientation tilt.

[0125] Figure 6a The superposition of the first and second fields of view in a first orientation of an exemplary imaging system is shown.

[0126] Figure 6b The superposition of the first and second fields of view in a second orientation of an exemplary imaging system is shown, wherein the second orientation is relative to... Figure 6a The first orientation is tilted, and the second optical route is used for the tool for second optical path stabilization, which remains in relation to... Figure 6a On the same orientation.

[0127] Figure 7a A schematic view of the first optical path of the imaging system with a volumetric hologram as the input coupling element is shown.

[0128] Figure 7b A schematic view of the first optical path of the imaging system with an embossed hologram as the input coupling element is shown.

[0129] Figure 7c A schematic view of the first optical path of the imaging system is shown, with an optically non-diffractive reflective inner surface serving as the input coupling element.

[0130] Figure 8a The theoretical predictions of the output coupling wavelength spectrum in the field of view, ranging from approximately 600 nm to 700 nm, are shown (top), as the incident angle of light from the field of view of the imaging system varies, and the intensity at 640 nm as the incident angle varies (bottom).

[0131] Figure 8b The theoretical predictions of the output coupling wavelength spectrum in the field of view, ranging from approximately 500 nm to 600 nm, are shown (top), as the incident angle of light from the field of view of the imaging system varies, and the intensity at 532 nm as the incident angle varies (bottom).

[0132] Figure 9a The first optical path field of view is shown, in which a diffuse surface illuminated with 639 nm light occupies the first field of view.

[0133] Figure 9b The first optical path field of view is shown, in which a diffuse surface illuminated with 533 nm light occupies the first field of view. 5. Detailed Implementation Especially through comparison Figure 2c and Figure 2d They demonstrate, for example, how tilting and / or shifting the first optical path using an ICE 20 with an incident normal x can cause light from a selected object region 81 to travel at a first angle α (see...). Figure 2c ) or second angle β (see Figure 2d The signal is received by ICE 20 and guided to sensor 50. For this purpose, ICE 20 (and, for example, the entire associated imaging system) in... Figure 2c and Figure 2d The exemplary orientations in the diagram are tilted at an angle γ.

[0135] Figure 2c The first field of view (FOV-1c) of the first optical path ICE 20 relative to the object to be imaged 80 (divided into grid patches) is shown, such that the selected object region 81 forms a first angle α with respect to the incident normal x of ICE 20.

[0136] Figure 2d The diagram shows the first field of view (FOV-1d) of the first optical path ICE 20 relative to the object 80 (shaded line), such that the selected object region 81 is imaged at a second angle β relative to the incident normal x' of ICE 20, the second angle being different from... Figure 2c The first angle α. Therefore, with Figure 2c In comparison, the ICE 20 is tilted at an angle γ; for example, this can be seen from the incident normal x (corresponding to Figure 2c The angle γ between the orientation of the incident normal x' and the incident normal can be seen.

[0137] Due to (for example) Figure 2b (As shown) Light of different wavelengths is transmitted at different angles in the first optical path, that is, it is brought to the sensor 50, and therefore at angle α (see Figure 2c ) and β (see Figure 2d The intensity of different wavelengths was collected from the same object region 81.

[0138] Figure 3a An exemplary embodiment of an imaging system 10 is shown, which includes a first optical path 60 and a second optical path 70. In this case, the first optical path 60 includes an ICE 20, a waveguide 30, and an OCE 40. The second optical path 70 includes an incident aperture in the region of the OCE 40. For clarity, only light incident on the sensor 50 from the central region of the second field of view is shown (using dashed lines) for the second optical path 70. However, the second field of view can typically be larger, for example, having a larger aperture than the sensor 50. Figures 3a to 3c It is similar in size to the first field of view in the image.

[0139] The imaging system 10 also includes tools 61 and 71 for reversibly switching between the first optical path 60 and the second optical path 70. For this purpose, the first tool 61 for reversible switching can open the first optical path 60, and the second component 71 for reversible switching can block the second optical path 70 (see...). Figure 3b ), or vice versa (see Figure 3c ).exist Figures 3a to 3c In this configuration, tools 61 and 71 for reversibly switching between the first optical path 60 and the second optical path 70 are attached to the starting point of the respective optical path 60 or 70. However, the tools may also be attached to any other location along the respective path, for example, between ICE 20 and OCE 40 in the first optical path 60. In any case, in some embodiments, tools 61 and 71 for reversible switching may be configured to block or open both or one of paths 60 and 70 simultaneously. In some embodiments, the tools may be configured such that only one of the two paths 60 and 70 can be open at any given time, and the other path must be blocked simultaneously; alternatively, the tools may block only both paths simultaneously. If only one of the two paths is open at any given time, tools 61 and 71 for reversible switching determine whether spectrally resolved image information reaches sensor 50 via the first optical path 60 at a given time, or whether “normal” (non-spectrally resolved) image information reaches sensor 50 via the second optical path 70.

[0140] The imaging system 10 also includes a sensor 50, to which light from the first optical path 60 and the second optical path 70 can be directed, depending on how the tools 61, 71 for reversibly switching between the first optical path 60 and the second optical path 70 are set or activated / deactivated.

[0141] Figure 3b It shows Figure 3a The imaging system 10 includes tools 61 and 71 for reversible switching, which open the first optical path 60 and block the second optical path 70. Therefore, in the illustrated exemplary case, spectrally resolved image information reaches the sensor 50 via the first optical path 60.

[0142] Figure 3c It shows Figure 3a The imaging system 10 includes tools 61 and 71 for reversible switching that block the first optical path 60 and open the second optical path 70. Therefore, in the illustrated exemplary case, "normal" (non-spectrally resolved) image information reaches the sensor 50 via the second optical path 70.

[0143] In a typical embodiment, the imaging system 10 can be configured to control tools 61, 71 for reversible switching, such that the tools switch multiple times between the first optical path 60 and the second optical path 70, and in each case perform acquisition, for example, at a frequency as described herein. During this switching sequence, the first field of view can then be tilted and / or shifted, for example by tilting and / or shifting the imaging system 10 and / or the first optical path 60, to change the angle of the observed object area relative to the incident normal of the ICE 20 (see, for example, in this regard). Figure 2c and Figure 2d (and description).

[0144] Figure 4a A schematic view of the imaging system 10, which has an ICE 20, an OCE 40, and a waveguide 30 with a wedge-shaped cross-section, is shown in the xz plane.

[0145] Figure 4b A schematic view of the imaging system 10, which has an ICE 20, an OCE 40, and a waveguide 30 that is bent in the xz plane, is shown in the xz plane.

[0146] Figure 4a and Figure 4b The imaging system 10 also includes a sensor 50 and tools 61, 71 for reversibly switching between the first optical path 60 and the second optical path 70. The tools 61, 71 for reversible switching and the sensor 50 should be understood as being related to... Figures 3a to 3c And those discussed in the description are exactly the same. Essentially, Figure 4a and Figure 4b A non-rectangular waveguide 30 can also be used. An exemplary waveguide 30 according to the solution of the invention may include, for example, parallel and / or non-parallel surfaces, surfaces having the same and / or different curvatures, coated and / or uncoated surfaces, and / or waveguides made of one or more materials. In a preferred embodiment, the waveguide 30 may be part of, or attached to, the screen of, a device (e.g., a handheld device, such as a cellular phone).

[0147] Figures 5a to 6b The superposition of the first field of view (FOV-1) and the second field of view under different (relative) orientations of the first optical path 60 and the second optical path 70 is shown. Here, in the first field of view (FOV-1), the spectral angle dependence is depicted in the form of the wavelengths that most efficiently couple input and / or output in the corresponding regions of the first field of view (FOV-1) through the brightness gradient: the shorter the wavelength, the darker the brightness. Figures 5a to 6b In the example, the object to be imaged 80 is a smiling face, and the image acquired via the second optical path 70 (corresponding to the second field of view) is depicted as superimposed on the first field of view FOV-1.

[0148] in this case, Figure 5a and Figure 5b A first imaging system is shown, wherein the first optical path and the second optical path can move together (e.g., tilt and / or shift). Figure 6a and Figure 6b Another exemplary imaging system is shown, in which the first and second optical paths can move relative to each other (e.g., tilt and / or shift). Figure 6a and Figure 6b In the example, the second optical path 70 is stabilized by a tool for stabilizing the second optical path 70. For this purpose, the stabilizing tool preferably includes a tool for rotation about at least one axis, more preferably a gimbal mount, as described herein. Typically, this results in some differences in the way the first FOV-1 and the second field of view are moved over the object to be imaged 80 in order to scan the object. These differences are based on... Figures 5a to 6b As shown.

[0149] Figure 5a The superposition of the first FOV-1 and the second field of view in a first orientation of an exemplary imaging system is shown. Figure 5a In the example, both the first optical path 60 and the second optical path 70 are oriented "vertically" or are oriented such that the incident normal is horizontal. Therefore, the image of the smiley face 80 is thus located at the center of the first field of view FOV-1.

[0150] Figure 5b This illustrates the superposition of a first FOV-1 and a second field of view in a second orientation of an exemplary imaging system, wherein the second orientation is relative to... Figure 5a The first orientation is tilted at an angle γ. Therefore, different colors are acquired in the region of the image to be acquired (see darker grayscale values), and relative to the first field of view FOV-1 and its... Figure 5a Even if it still has position 80, the smiley face 80' moves upward.

[0151] By adjusting the movement of object 80, various acquisitions of the first field of view can be combined to create a color image.

[0152] In another embodiment where the second optical path 70 is stabilized using a tool for stabilizing the second optical path 70, a different superposition occurs: Figure 6a This illustrates the superposition of the first FOV-1 and the second field of view in a first orientation of an exemplary imaging system, which is consistent with... Figure 5a The situation is the same. However, if Figure 6a If the exemplary embodiment is tilted, then a situation arises that is consistent with... Figure 5b The situations shown are different: Figure 6bThis illustrates the superposition of the first FOV-1 and the second field of view in a second orientation of an exemplary imaging system, wherein the second orientation is relative to... Figure 6a The first orientation is tilted, and the second optical path 70 is held in place by a tool for stabilizing the second optical path 70. Figure 6a On the same orientation. Therefore, when the first field of view (FOV-1) shifts, the object to be imaged 80 remains centered, such that the area surrounding the object 80 is relative to... Figure 6a The images are formed at different angles and therefore at different colors for different object regions. Therefore, in this example, the decisive angular information used for post-processing of the individual acquisitions of the first field of view (FOV) will be the angular information providing information about the tilt angle γ between the first optical path 60 and the second optical path 70.

[0153] Figures 7a to 7c An embodiment of the imaging system 10 is shown in the xz plane. This imaging system has a waveguide 30, an OCE 40, and various ICEs 20, wherein, for clarity, only the first optical path is shown: Figure 7a A schematic view of an imaging system 10 with a volume hologram as the first optical path of an ICE 20 is shown. In the context of this invention, volume holograms generally produce good selectivity.

[0154] Figure 7b A schematic view of the first optical path of the imaging system 10 with an embossed hologram as the ICE 20 is shown. For example, such an embossed hologram can be written, engraved, and / or pressed into the surface of the waveguide 30.

[0155] The deflection of light incident on ICE 20 Figure 7a and Figure 7b The situation is basically similar, and is affected by the corresponding exposure of the hologram.

[0156] Figure 7c A schematic view of the first optical path of an imaging system 10 having an optically non-diffractive reflective inner surface as an ICE 20 is shown. In this configuration, light enters the waveguide 30 through an entrance pupil (not shown) where the arrows intersect, and is deflected by the optically non-diffractive reflective inner surface to an OCE 40, which then performs spectral separation on the light. In principle, the optically non-diffractive reflective inner surface as the ICE 20 can be an advantageous and simple alternative, saving cost and space and, moreover, being able to deflect a larger proportion of the incident light, thus improving acquisition in low-intensity conditions.

[0157] Figure 8aThe theoretical predictions (top) of the output coupling wavelength spectrum in the field of view, ranging from approximately 600 nm to 700 nm, are shown as the incident angle of light from the imaging system varies with the field of view, and the intensity at 640 nm as a function of the incident angle (bottom). It has been found that the output coupling spectrum at 640 nm can theoretically have an angular width of 3.7°.

[0158] Figure 8b The theoretical predictions (top) of the output coupling wavelength spectrum in the field of view, ranging from approximately 500 nm to 600 nm, are shown as the incident angle of light from the same imaging system varies with the field of view, and the intensity at 532 nm as a function of the incident angle (bottom). It has been found that the output coupling spectrum at 532 nm can theoretically have an angular width of 2.3.

[0159] Figure 9a The first optical path field of view is shown, in which a diffuse surface illuminated with 639 nm light occupies the first field of view. The light intensity detected by the sensor is represented by grayscale values ​​(white corresponds to high intensity, and black corresponds to zero intensity).

[0160] Figure 9b The acquisition of the first optical path field of view is shown, in which a diffuse surface illuminated with 533 nm light occupies the first field of view. The light intensity detected by the sensor is represented by grayscale values ​​(white corresponds to high intensity, and black corresponds to zero intensity).

[0161] exist Figure 9a and Figure 9b In this example, light is detected in a slightly curved region within the field of view. The angle dependence occurs primarily perpendicular to the arc profile at the center of the arc, i.e., in the vertical direction in these examples.

[0162] Figure 9a The example shows that the light at 639 nm can have an angular width of 6.7° (approximately 3° larger than the theoretically predicted angular width), and... Figure 9b The results show that light at 533 nm in the same example can have an angular width of 3.5° (more than 1.2° larger than the theoretically predicted angular width).

[0163] Figure 9a and Figure 9b This illustrates that the ICE and / or OCE can be configured to at least partially separate the light from the first field of view in such a way that at least one region of the optical sensor can be assigned predetermined color information. For example, this could involve... Figure 9a and Figure 9bThe illustrations show that curved arc regions within the first field of view in a real system can be configured to couple color / wavelength outputs to a sensor, such that the color / wavelength can be assigned to a corresponding region on the sensor.

Claims

1. An imaging system (10) for creating a color image from multiple acquisitions, wherein, The imaging system (10) includes: A first optical path (60) having a first field of view (FOV-1), the first optical path (60) comprising: Input coupling element ICE (20); and Output coupling element OCE (40); The ICE (20) is configured to at least partially deflect light incident from the first field of view (FOV-1) onto the ICE (20) to the OCE (40). The OCE (40) is configured to output at least partially the deflected light; Wherein, the ICE (20) and / or the OCE (40) are configured to at least partially perform spectral separation on the light from the first field of view (FOV-1); and The second optical path (70) has a second field of view and includes an entrance aperture.

2. The imaging system (10) as claimed in claim 1, further comprising an optical sensor (50), preferably a light intensity sensor, wherein, The first optical path (60) and / or the second optical path (70) are configured to allow at least some of the light from the first field of view (FOV-1) and / or the second field of view to be incident on the optical sensor (50).

3. The imaging system (10) of claim 1 or 2 further includes a tool for determining relative position information between a first image and a second image of the first field of view (FOV-1) acquired by the optical sensor (50).

4. The imaging system (10) as claimed in claim 3, wherein, The tool for determining relative position information is based at least in part on multiple acquisitions of the second field of view, preferably by comparing at least two acquisitions of the multiple acquisitions of the second field of view.

5. The imaging system (10) as claimed in claim 3 or 4, wherein, The determining tool is configured to determine the position based at least in part on data from a position sensor and / or an acceleration sensor.

6. The imaging system (10) as claimed in any one of claims 2 to 5, further comprising tools for stabilizing the optical sensor (50), wherein, The stabilizing tool preferably includes a tool for translation and / or a tool for rotation about at least one axis, and particularly preferably a gimbal mount.

7. The imaging system (10) as claimed in any one of claims 2 to 6, wherein, The ICE (20) and / or the OCE (40) are configured to at least partially perform spectral separation of the light from the first field of view (FOV-1) in such a way that at least one region of the optical sensor (50) is assigned predetermined color information.

8. The imaging system (10) of any one of claims 1 to 7 further includes tools (61, 71) for reversibly switching between the first optical path (60) and the second optical path (70).

9. The imaging system (10) as claimed in claim 8, wherein, The tool (61, 71) for reversible switching includes at least one electrochromic layer.

10. The imaging system (10) as claimed in claim 8 or 9, wherein, The tools (61, 71) for reversible switching are configured to periodically switch between the first optical path (60) and the second optical path (70).

11. The imaging system (10) of any one of claims 1 to 10 further includes a tool for automatically changing, and more specifically for automatically tilting, the first field of view (FOV-1).

12. The imaging system (10) as claimed in claim 11, wherein, The tool for automatically changing the first field of view (FOV-1) includes a tool for rotating about at least one axis.

13. The imaging system (10) as claimed in claim 3 or any one of claims 4 to 12 when referring to claim 3, wherein, The imaging system (10) is also configured to create a color image based at least in part on the first image and the second image and the relative position information between the first image and the second image.

14. The imaging system (10) according to any one of claims 1 to 13, wherein, The ICE (20) and / or the OCE (40) include holographic optical elements, preferably RGB holograms, volumetric holograms and / or relief holograms.

15. The imaging system (10) according to any one of claims 1 to 14, wherein, The ICE (20) and / or the OCE (40) include reflective optical non-diffractive elements.

16. A handheld device, preferably a cellular phone, having an imaging system (10) as claimed in any one of claims 1 to 15.

17. A method for creating a color image from multiple acquisitions obtained by an imaging system (10), wherein, The method includes: The imaging system (10) acquires a first image from a first position in a first field of view (FOV-1) and a second image from a second position, the imaging system (10) comprising: A first optical path (60) having the first field of view (FOV-1), the first optical path (60) comprising: Input coupling element ICE (20); and Output coupling element OCE (40); The ICE (20) is configured to at least partially deflect light incident on the ICE (20) from the first field of view of the ICE (20) to the OCE (40). The OCE (40) is configured to output at least partially the deflected light; Wherein, the ICE (20) and / or the OCE (40) are configured to at least partially perform spectral separation on the light from the first field of view (FOV-1); Store the first image and the second image, as well as the relative position information between the first image and the second image.

18. A method for creating a color image from multiple acquisitions obtained by an imaging system (10), wherein, The method includes: At least a first image and a second image of the first field of view (FOV-1) of the imaging system (10) are obtained, the imaging system (10) comprising: A first optical path (60) having the first field of view, the first optical path (60) comprising: Input coupling element ICE (20); and Output coupling element OCE (40); The ICE (20) is configured to at least partially deflect light incident from the first field of view (FOV-1) onto the ICE (20) to the OCE (40). The OCE (40) is configured to output at least partially the deflected light; Wherein, the ICE (20) and / or the OCE (40) are configured to at least partially perform spectral separation on the light from the first field of view (FOV-1); Determine the relative position information between the first image and the second image.

19. The method of claim 18, wherein, The method further includes storing the first image and the second image, as well as the determined relative position information between the first image and the second image.

20. The method according to any one of claims 17 to 19, wherein, The method further includes creating a color image based at least in part on the first image and the second image, as well as the relative position information.

21. A method for establishing color information of an object, wherein, The method includes: Multiple acquisitions of the object are performed using the imaging system (10) as described in any one of claims 1 to 15; and The color information of the object is extracted from the collected data, preferably through spectral analysis.

Images