Neuromorphic VLSI vision system for real-time texture segregation
Neuromorphic VLSI vision system for real-time texture segregation
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DOI：
10.1016/j.neunet.2008.07.003
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发表时间：
2008-10
期刊：
影响因子：
--
通讯作者：
K. Shimonomura;T. Yagi
中科院分区：
文献类型：
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作者：
K. Shimonomura;T. Yagi
尽管单个神经元的响应速度远低于半导体器件，但大脑的视觉系统可以以极低的功耗实时感知外部场景。视觉通路中的神经元使用并行和分层结构产生它们的接受野。从工程学的角度来看，视觉皮层的这种结构对于设计一种新的感知系统是非常有趣和重要的。本研究的目的是开发一种视觉系统硬件，该硬件的设计灵感来自于V1中的分层视觉处理，用于实时纹理分离。该系统由硅视网膜、定向芯片和现场可编程门阵列（FPGA）电路组成。硅视网膜模拟脊椎动物视网膜的神经回路，并表现出类似拉普拉斯-高斯的接受野。定向芯片选择性地聚集硅视网膜的多个像素，以产生类似gabor的接受野，通过模仿Hubel和Wiesel提出的前馈模型来调整到不同的方向。FPGA电路接收定向芯片的输出并计算复杂单元的响应。利用该系统实时计算简单细胞在不同方向和空间频率下的神经图像。利用多芯片系统获得的定向选择输出，基于心理物理学和神经生理学启发的计算模型进行实时纹理分离。通过多芯片系统的两个正交取向的感受场对纹理图像进行滤波，并结合FPGA对不同纹理方向的图像进行分离。该系统还可用于研究由简单细胞和复杂细胞结合而得到的高阶细胞的功能。
The visual system of the brain can perceive an external scene in real-time with extremely low power dissipation, although the response speed of an individual neuron is considerably lower than that of semiconductor devices. The neurons in the visual pathway generate their receptive fields using a parallel and hierarchical architecture. This architecture of the visual cortex is interesting and important for designing a novel perception system from an engineering perspective. The aim of this study is to develop a vision system hardware, which is designed inspired by a hierarchical visual processing in V1, for real time texture segregation. The system consists of a silicon retina, orientation chip, and field programmable gate array (FPGA) circuit. The silicon retina emulates the neural circuits of the vertebrate retina and exhibits a Laplacian–Gaussian-like receptive field. The orientation chip selectively aggregates multiple pixels of the silicon retina in order to produce Gabor-like receptive fields that are tuned to various orientations by mimicking the feed-forward model proposed by Hubel and Wiesel. The FPGA circuit receives the output of the orientation chip and computes the responses of the complex cells. Using this system, the neural images of simple cells were computed in real-time for various orientations and spatial frequencies. Using the orientation-selective outputs obtained from the multichip system, a real-time texture segregation was conducted based on a computational model inspired by psychophysics and neurophysiology. The texture image was filtered by the two orthogonally oriented receptive fields of the multi-chip system and the filtered images were combined to segregate the area of different texture orientation with the aid of FPGA. The present system is also useful for the investigation of the functions of the higher-order cells that can be obtained by combining the simple and complex cells.