Multi-scale scattered light field synchronous measurement method based on computational imaging

Abstract

The invention relates to the technical field of optical measurement, in particular to a multi-scale scattering light field synchronous measurement method based on computational imaging, an overall measurement optical system comprises a hemispherical scattering dome, an aspheric reflector and a detection system, and the detection system comprises a detection optical assembly and a detector. Comprising the steps that multi-scale scattering light field information of a to-be-measured target body is collected, light field information interpretation processing is conducted on the collected multi-scale scattering light field information data, and an overall measurement optical system is a large-view-field and large-depth-of-field optical system for imaging of different object distances and belongs to an off-axis turn-back type optical system. A complex mechanical motion structure is replaced by an optical device, and synchronous'snapshot 'measurement of multi-scale scattered light fields on the surface of a to-be-measured target body without a motion mechanism is realized.

Description

Technical Field

[0001] The present invention relates to the field of optical measurement technology, and in particular to synchronous measurement of multi-scale scattered light fields. Background Art

[0002] Multi-scale scattered light fields include multi-angle, multi-spectral, and dynamic and static scattered light fields, which can accurately describe the spatial optical properties of the surface of the target to be measured. The synchronous measurement of multi-scale scattered light fields has important application value in the fields of ground target remote sensing, ecological environment monitoring, stray light suppression, and graphics rendering. However, most of the existing scattered light field measurement methods are based on mechanical measurement methods, which use complex mechanical motion structures to move the target to be measured. The above measurement system itself has a complex structure and low measurement efficiency, and it is impossible to measure dynamic scattered light fields. Summary of the invention

[0003] In order to solve the technical problems that the existing mechanical measurement methods have low efficiency in measuring scattered light fields and cannot measure dynamic scattered light fields, the present invention proposes a "multi-scale scattered light field synchronous measurement method based on computational imaging".

[0004] A synchronous measurement method for multi-scale scattered light fields based on computational imaging, step 1, collecting multi-scale scattered light field information of a target body to be measured (5): the overall measurement optical system includes a hemispherical scattering dome 1, an aspherical reflector 2, and a detection system 3, wherein the detection system 3 includes a detection optical component 31 and a detector 32, such as Figure 1 and Figure 2 As shown, the hemispherical scattering dome 1 is the object surface of the overall measurement optical system. After the light source 4 emits a light beam through the hemispherical scattering dome 1 to illuminate the surface of the target body 5 to be measured, the multi-scale scattered light of the surface of the target body 5 to be measured in the hemispherical space is collected and scattered by the hemispherical scattering dome, and the different object distances of the hemispherical scattering dome surface are imaged through the combination of the aspherical reflector 2 and the detection optical component 31, and finally reach the surface of the detector 32.

[0005] Step 2, the detector (32) performs light field information interpretation processing on the collected multi-scale scattered light field information data: through the light field transmission matrix and the calculation of the intrinsic scattered light field point spread function, the mapping between the intrinsic scattered light field distribution information and the characteristic physical quantity of the target to be measured is reconstructed, and the spatial optical characteristics of the intrinsic information of the multi-scale scattered light field of the target to be measured are solved based on the inverse problem of the deep learning model to obtain E′(x, y)=H0{E′(x, y)}, and the light field information interpretation processing is completed to realize the synchronous measurement of the multi-scale scattered light field, wherein (x, y) is a two-dimensional coordinate point in a certain space, E(x, y) is the intrinsic scattered light field distribution of the target to be measured, E′(x, y) is the scattered light field distribution received by the detector 32 after passing through the detection optical component 31, and H0{E′(x, y)} is the inverse problem solving function of the deep learning model.

[0006] Technical effects:

[0007] The present invention discloses a synchronous measurement method of multi-scale scattered light fields based on computational imaging, which is suitable for synchronously acquiring multi-scale scattered light field distribution information within the hemispherical space range of different target bodies to be measured, and solves the problem that the existing mechanical measuring device has low measurement efficiency and cannot measure the dynamic scattered light field.

[0008] The present invention combines the scattering characteristics of the hemispherical scattering dome, refractive-reflective panoramic imaging and computational imaging technology to collect and image the light carrying scattered light field information distributed in the hemispherical space and interpret the light field information. The overall measurement optical system is a large field of view and large depth of field optical system for imaging at different object distances, and is an off-axis reentrant optical system. Optical devices replace complex mechanical motion structures to achieve synchronous "snapshot" measurement of multi-scale scattered light fields on the surface of a target to be measured without the need for a motion mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of the optical path of the multi-scale scattered light field measurement process of the present invention.

[0010] Figure 2 It is a schematic diagram of the overall measurement optical system structure of the present invention.

[0011] Figure 3 It is a schematic diagram of the multi-scale scattered light field information interpretation process of the present invention.

[0012] Figure 4 Schematic diagram of the measurement results of multi-scale scattered light field information distribution of opalescent glass.

[0013] Figure 5 Schematic diagram of the actual results of the distribution of multi-scale scattered light field information of opalescent glass obtained through light field information interpretation processing. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by ordinary technicians in the field without creative work by adopting the embodiments of the present invention are within the scope of protection of the present invention.

[0015] In the embodiment of the present invention, the hemispherical scattering dome 1 has a coating with a near-Lambertian scattering characteristic, and its radius is 500 mm.

[0016] In the embodiment of the present invention, Figure 2As shown, l1, l2, l3, l4, l5, and l6 are different object distances in the hemispherical space, and the different object distances on the surface of the hemispherical scattering dome 1 are imaged by combining the aspherical reflector 2 and the detection optical component 31.

[0017] In the embodiment of the present invention, the specific parameters of the aspheric reflector 2 are as follows:

[0018]

[0019] Where c is the curvature of the vertex of the aspherical reflector 2, k is the cone coefficient, and a i (i=0,1,3,4) are the coefficients of higher-order terms.

[0020] In the embodiment of the present invention, the detector 32 performs light field information interpretation processing on the collected multi-scale scattered light field information data, such as Figure 3 As shown, based on the light field information transmission theory, the scattered light field transmission process of the target to be measured is analyzed and measured, and the mapping between the intrinsic scattered light field distribution information and the characteristic physical quantity of the target to be measured is reconstructed by calculating the light field transmission matrix and the intrinsic scattered light field point spread function. Based on the inverse problem of the deep learning model, the spatial optical characteristics of the intrinsic information of the multi-scale scattered light field of the target to be measured are solved to obtain E′(x, y)=H0{E′(x, y)}, and the light field information interpretation and processing are completed to realize the synchronous measurement of the multi-scale scattered light field; wherein, (x, y) is a two-dimensional coordinate point in a certain space, E(x, y) is the intrinsic scattered light field distribution of the target to be measured, E′(x, y) is the scattered light field distribution received by the detector 32 after passing through the detection optical component 31, and H0{E′(x, y)} is the inverse problem solving function of the deep learning model. The scattered light field distribution is reconstructed for the target to be measured, and the system measurement accuracy is obtained by comparing the reconstructed scattered light field distribution of the target to be measured with the intrinsic scattered light field distribution.

[0021] like Figure 4 and Figure 5 As shown, taking opal glass as the target to be measured, the present invention realizes synchronous measurement of the multi-scale scattered light field of opal glass. Figure 4 is the measurement result of the multi-scale scattered light field information distribution of opal glass obtained based on the overall measurement optical system, Figure 5 The actual result of the multi-scale scattered light field information distribution of opal glass obtained after light field information interpretation processing, that is, the measurement result of the scattered light field information distribution model of opal glass based on the multi-scale scattered light field synchronous measurement method of computational imaging. From the result, it can be concluded that its scattered light field distribution is close to the Lambertian distribution, which belongs to a nearly isotropic medium with Lambertian scattering characteristics. The measurement results are consistent with the actual spatial optical properties of opal glass.

[0022] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0023] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

Claims

1. A multi-scale scattered light field synchronous measurement method based on computational imaging, characterized in that: Step 1: Collect multi-scale scattered light field information of the target object (5): The overall measurement optical system comprises a hemispherical scattering dome (1), an aspherical reflector (2), and a detection system (3). The detection system (3) comprises a detection optical component (31) and a detector (32). The hemispherical scattering dome (1) is the object surface of the overall measurement optical system. After a light beam emitted by a light source (4) is irradiated onto the surface of a target body (5) to be measured through the hemispherical scattering dome (1), multi-scale scattered light from the surface of the target body (5) to be measured in the hemispherical space is collected and scattered by the hemispherical scattering dome (1). The hemispherical scattering dome (1) is combined with the aspherical reflector (2) and the detection optical component (31) to image the surface of the hemispherical scattering dome (1) at different object distances, and finally reaches the surface of the detector (32). Step 2: The detector (32) performs light field information interpretation processing on the collected multi-scale scattered light field information data: By using the light field transmission matrix and calculating the intrinsic scattered light field point spread function, the mapping between the intrinsic scattered light field distribution information and the characteristic physical quantity of the target to be measured is reconstructed, and the spatial optical characteristics of the intrinsic information of the multi-scale scattered light field of the target to be measured are solved based on the inverse problem of the deep learning model to obtain E′(x, y)=H0{E′(x, y)}, complete the light field information interpretation and processing, and realize the synchronous measurement of the multi-scale scattered light field, wherein (x, y) is a two-dimensional coordinate point in a certain space, E(x, y) is the intrinsic scattered light field distribution of the target to be measured, E′(x, y) is the scattered light field distribution received by the detector (32), and H0{E′(x, y)} is the inverse problem solving function of the deep learning model.

2. The method for synchronously measuring multi-scale scattered light fields based on computational imaging according to claim 1, characterized in that: The hemispherical scattering dome (1) has a coating with a near-Lambertian scattering characteristic and has a radius of 500 mm.

3. The method for synchronously measuring multi-scale scattered light fields based on computational imaging according to claim 1, characterized in that: The specific parameters of the aspheric reflector (2) are as follows: Where c is the curvature of the vertex of the aspherical reflector (2), k is the cone coefficient, and a i (i=0,1,3,4) are the coefficients of higher-order terms.

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