An improved nonuniformity correction algorithm for IRFPA
To improve nonuniformity correction real-time performance of infrared focal plane arrays (IRFPA), a novel compression nonuniformity correction algorithm is proposed. In this paper the basic principle of the proposed algorithm are expounded, and its real-time performance is tested by hardware. Experimental results show that the proposed algorithm has the less calculation and the higher speed than traditional nonuniformity correction algorithm based on blackbody, and this helps to realization of real-time nonuniformity correction of IRFPA.
Two-point nonuniformity correction based on LMS
In real-time system, the Infrared Focal Plane Array (IRFPA) should be compensated in traditional method of two-point temperature non-uniformity correction (NUC) before system was used every time, which make the system complex. Based on discussion of traditional two-point temperature NUC algorithm, Two-point temperature NUC based on least mean square (LMS) algorithm was proposed in the paper. In the view of the LMS algorithm theory, the correction gain and offset coefficients were iterated one by one during image processing, so that the expected correction result were obtained in little time. At the same time, the correction and coefficients iteration processes were completed in FPGA and DSP respectively, and make the arithmetic structure simple. The simplified structure, low cost and out-door suitable operation-systems are the merits of the system.
Semiautomated quantification of the fibrous tissue response to complex three-dimensional filamentous scaffolds using digital image analysis.
Fibrosis represents a relevant response to the implantation of biomaterials, which occurs not only at the tissue-material interface (fibrotic encapsulation) but also within the void fraction of complex three-dimensional (3D) biomaterial constructions (fibrotic ingrowth). Usual evaluation of the biocompatibility mostly depicts fibrosis at the interface of the biomaterial using semiquantitative scores. Here, the relations between encapsulation and infiltrating fibrotic growth are poorly represented. Virtual pathology and digital image analysis provide new strategies to assess fibrosis in a more differentiated way. In this study, we adopted a method previously used to quantify fibrosis in visceral organs to the quantification of fibrosis to 3D biomaterials. In a proof-of-concept study, we transferred the "Collagen Proportionate Area" (CPA) analysis from hepatology to the field of biomaterials. As one task of an experimental animal study, we used CPA analysis to quantify the fibrotic ingrowth into a filamentous scaffold after subcutaneous implantation. We were able to demonstrate that the application of the CPA analysis is well suited as an additional fibrosis evaluation strategy for new biomaterial constructions. The CPA method can contribute to a better understanding of the fibrotic interactions between 3D scaffolds and the host tissue responses.