This disclosure relates generally to image acquisition and more particularly to systems and methods for lensless compressive image acquisition.
Image acquisition—as performed by contemporary digital image or video systems and methods—generally involves the acquisition and immediate compression of large amounts of raw image or video data. Frequently, such systems and methods require expensive sensors and significant computational capabilities.
An advance is made in the art according to an aspect of the present disclosure directed to systems, structures, devices and methods for lensless compressive image acquisition.
Viewed from one aspect, the present disclosure is directed to a method for compressive image acquisition including the selective operation of a shutter assembly having an array of individual shutter elements according to a basis, detecting light transmitted through the shutter assembly through the effect of a detector, and making compressive measurements of the detected light. Advantageously, a number of such compressive measurements may be made to produce an image.
Furthermore, images may be obtained with a single detection element while measuring the image far fewer times than the number of pixels associated with contemporary cameras and images they produce. Since—in a preferred representative embodiment only a single detection element is employed—it may advantageously be adapted to images at wavelengths that are difficult or impossible with contemporary CCD or CMOS imagers.
In sharp contrast to the prior art, lensless compressive image acquisition according to aspect of the present disclosure does not employ micromirrors or lenses or a large array of photon detectors such wherein images comprise a number of pixels as with ordinary cameras.
A more complete understanding of the present disclosure may be realized by reference to the accompanying drawings in which:
a) and 3(b) depicts (a) an exemplary set of compressive measurements as obtained from a lensless compressive image acquisition system according to an aspect of the present disclosure and (b) relationship(s) between LCD element states and values in measurement basis according to an aspect of the present disclosure;
a) and 4(b) depicts (a) a schematic of a multi-detector lensless compressive image acquisition according to an aspect of the present disclosure and (b) a top view of the multi-detector lensless compressive image acquisition in (a);
a) and 5(b) depict (a) a schematic of a multi-detector lensless compressive image acquisition having an array of detectors according to an aspect of the present disclosure and (b) a top view of the multi-detector lensless compressive image acquisition system in 5(a);
The illustrative embodiments are described more fully by the Figures and detailed description. The inventions may, however, be embodied in various forms and are not limited to embodiments described in the Figures and detailed description
The following merely illustrates the principles of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its spirit and scope.
Furthermore, all examples and conditional language recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions.
Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.
Thus, for example, it will be appreciated by those skilled in the art that the diagrams herein represent conceptual views of illustrative structures embodying the principles of the disclosure. Accordingly, those skilled in the art will readily appreciate the applicability of the present disclosure to a variety of applications.
In the claims hereof any element expressed as a means for performing a specified function is intended to encompass any way of performing that function. This may include, for example, a) electrical or mechanical or optical elements which performs that function or combinations thereof, or b) software in any form, including therefore firmware, microcode or the like combined with appropriate circuitry for executing that software to perform the function, as well as optical and/or mechanical elements coupled to software controlled circuitry, if any. The invention as defined resides in the fact that the functionalities provided by the various recited means are combined and brought together in the manner which the claims call for. Applicants thus regard any means which can provide those functionalities as equivalent as those shown herein.
Turning now to
With reference now to
As shown further in
By way of example only, the shutter array 220 is depicted in
Additionally, we note that while not explicitly shown in the Figures, light which is reflected from the object 210 is not substantially deflected/refracted or otherwise along its path to the detector(s) 230. That is to say, the shutters comprising the shutter array 220 do not deflect the light, they only permit/deny its passage therethrough.
Operationally, a number of compressive measurements 250 are made during a representative image acquisition. Turning now to
For example, and as noted previously, the example LCD array 320 is an 8×8 array of individual LCD elements for a total of 64 elements. Consequently, an individual measurement, i.e., Bk, will have 64 elements, one for each of the LCD elements in LCD array 320.
As may be further observed from this
Furthermore, each element of the individual basis corresponds to and is indicative of whether or not the particular LCD element was open or closed during a particular acquisition. For example, as depicted in
In this example shown in
Finally, as shown further in this
a) shows a schematic depiction of a compressive image acquisition system 400 according to yet another aspect of the present disclosure. In this example depicted in
Similar to that shown previously, the LCD shutter array 450 in this
b) is a schematic top view of the arrangement depicted in 4(a). More particularly, an object 410 is shown at a front portion of the system 440 including the LCD array 450 and detectors 420[1], 420[2], each positioned a distance f from the LCD array 450 and spaced apart by a distance d. Generally, the detectors 420[1], 420[2], are positioned on a plane parallel to the LCD array 450 on a common horizontal line.
Advantageously, it may be apparent to those skilled in the art that the configuration depicted in
a) shows a schematic depiction of a compressive image acquisition system 500 according to yet another aspect of the present disclosure which utilizes an array of detectors. In this example depicted in
b) is a schematic top view of the arrangement depicted in 5(a). More particularly, and with simultaneous reference to
Similarly to that described previously, each individual detector 520[1,1], 520[1,2], . . . ,520[i,j] in the detector array 520 makes a measurement of a given measurement basis Bk(i). As was the situation before, each measurement may be used for one of a number of images having a particular point of view with respect to the same measurement basis Bk(i). Alternatively, the individual values may serve as multiple measurements of the same image, with different basis B1k(i) B2k(i), . . . BNk(i) where N is the number of individual detectors in the detector array 520
Advantageously, the distance between the LCD array and the detector determines the field of view of the image taken by the lensless camera. A shorter distance results in a larger field of view, and a larger distance results in a smaller field of viewer. A desired field of view can be obtained by appropriately adjusting the distance.
As may be further appreciated by those skilled in the art, when a single detector is used in a compressive image acquisition system according to the present disclosure, it is generally the resolution of the LCD array employed which determines the resolution of the overall system. Advantageously, and according to an aspect of the present disclosure, the overall resolution of any images acquired may be increased through the use of multiple detectors with a common LCD array.
a) and 7(b) depict the geometric considerations for increasing the resolution of a compressive image acquisition system according to an aspect of the present disclosure wherein a pair of detectors are employed.
Referring to
In this manner, a lensless compressive image acquisition camera according to the present disclosure may be conveniently operated and produce consistent results for a particular application.
Those skilled in the art will readily appreciate that the computer system 900 may be programmed to generate basis, operate the shutter assembly and determine and record compressive measurements. Similarly, it may operate any of a number of actuators for moving the shutter and detector(s), or to store measurements and generate images from the stored measurements.
As depicted, computer system 900 includes processor 910, memory 920, storage device 830, and input/output structure(s) 940. Processor 910 executes instructions in which embodiments of the present disclosure may comprise steps described in conjunction with one or more of the Figures. Such instructions may be stored in memory 920 or storage device 930. Data and/or information may be received an output using one or more input/output devices.
Memory 920 may store data and may be computer-readable medium, such as volatile or non-volatile memory. Storage device 930 may provide storage for system 900 including for example, the previously described steps/methods. In various aspects, storage devices 930 may be a flash memory device, a disk drive, an optical disk device or a tape device employing magnetic, optical, or other recording technologies.
At this point, while we have discussed and described the invention using some specific examples, those skilled in the art will recognize that our teachings are not so limited. Accordingly, the invention should be only limited by the scope of the claims attached hereto.