Generalized free-space diffuse photon transport model based on the influence analysis of a camera lens diaphragm

Video and Image Processing System Laboratory, School of Electronic Engineering, Xidian University, Xi’an, Shaanxi 710071, China.
Applied Optics (Impact Factor: 1.78). 10/2010; 49(29):5654-64. DOI: 10.1364/AO.49.005654
Source: PubMed


The camera lens diaphragm is an important component in a noncontact optical imaging system and has a crucial influence on the images registered on the CCD camera. However, this influence has not been taken into account in the existing free-space photon transport models. To model the photon transport process more accurately, a generalized free-space photon transport model is proposed. It combines Lambertian source theory with analysis of the influence of the camera lens diaphragm to simulate photon transport process in free space. In addition, the radiance theorem is also adopted to establish the energy relationship between the virtual detector and the CCD camera. The accuracy and feasibility of the proposed model is validated with a Monte-Carlo-based free-space photon transport model and physical phantom experiment. A comparison study with our previous hybrid radiosity-radiance theorem based model demonstrates the improvement performance and potential of the proposed model for simulating photon transport process in free space.

Download full-text


Available from: Jimin Liang, Oct 07, 2015
15 Reads
  • Source
    • "where J(r) is the outward flux at point r of the body surface; T is the detection space constructed by all of the pixels in the bioluminescent image; E(r d ) is the light power received at point r d of the detection space; r vd is the imaging point of r d on the virtual detector plane; θ s is the included angle between the unit direction vector from r vd to r and the normal vector of the surface point r; θ d is the included angle between the unit direction vector and the normal vector of the virtual detector point r vd ; α(r d , r) is the field visibility factor and β(r d , r; Ω D ) is the effective visibility factor, which are generalized from the analysis of the camera lens diaphragm as presented in [19] and are used to determine whether the energy mapping relationship exists between the two points; and Ω D represents the size of effective aperture and is dependent on the camera lens diaphragm. The detailed derivation of Eq. (5) can refer to the literatures [19] [20], and the diagram for the procedure of the surface light flux recovery and descriptions of the related parameters are intuitively described in Fig. 2 "
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a method for mapping the two-dimensional (2D) bioluminescent images (BLIs) onto a three-dimensional (3D) body surface derived from the computed tomography (CT) volume data. This mapping includes two closely-related steps, the spatial registration of the 2D BLIs into the coordinate system of the CT volume data and the light flux recovering on the body surface from BLIs. By labeling markers on the body surface, we proposed an effective registration method to achieve the spatial position alignment. The subsequent light flux recovering is presented based on the inverse process of the free-space light transport model and taking the influence of the camera lens diaphragm into account. Incorporating the mapping procedure into the bioluminescence tomography (BLT) reconstruction, we developed a dual-modality BLT and CT imaging framework to provide both optical and anatomical information. The accuracy of the registration and the light flux recovering methods were evaluated via physical phantom experiments. The registration method was found to have a mean error of 0.41 mm and 0.35 mm in horizontal and vertical direction, and the accuracy of the light flux recovering method was below 5%. Furthermore, we evaluated the performance of the dual-modality BLT/CT imaging framework using a mouse phantom. Preliminary results revealed the potential and feasibility of the dual-modality imaging framework.
    Journal of X-Ray Science and Technology 01/2012; 20(1):31-44. DOI:10.3233/XST-2012-0317 · 1.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this contribution, we present an all-optical quantitative framework for bioluminescence tomography with non-contact measurement. The framework is comprised of four indispensable steps: extraction of the geometrical structures of the subject, light flux reconstruction on arbitrary surface, calibration and quantification of the surface light flux and internal bioluminescence reconstruction. In particular, the geometrical structures are retrieved using a completely optical method and captured under identical viewing conditions with the bioluminescent images. As a result, the proposed framework avoids the utilization of computed tomography or magnetic resonance imaging to provide the geometrical structures. On the basis of experimental measurements, we evaluate the performance of the proposed all-optical quantitative framework using a mouse shaped phantom. Preliminary result reveals the potential and feasibility of the proposed framework for bioluminescence tomography.
    International Journal of Automation and Computing 02/2012; 9(1). DOI:10.1007/s11633-012-0618-4
  • [Show abstract] [Hide abstract]
    ABSTRACT: A void region exists in some biological tissues, and previous studies have shown that inaccurate images would be obtained if it were not processed. A hybrid radiosity-diffusion method (HRDM) that couples the radiosity theory and the diffusion equation has been proposed to deal with the void problem and has been well demonstrated in two-dimensional and three-dimensional (3D) simple models. However, the extent of the impact of the void region on the accuracy of modeling light propagation has not been investigated. In this paper, we first implemented and verified the HRDM in 3D models, including both the regular geometries and a digital mouse model, and then investigated the influences of the void region on modeling light propagation in a heterogeneous medium. Our investigation results show that the influence of the region can be neglected when the size of the void is less than a certain range, and other cases must be taken into account.
    Applied Optics 01/2013; 52(3):400-8. DOI:10.1364/AO.52.000400 · 1.78 Impact Factor
Show more