Pulse-domain digital image processing for vision chips employing low-voltage operation in deep-submicrometer technologies
Pulse-domain digital image processing for vision chips employing low-voltage operation in deep-submicrometer technologies
复制标题
在深亚微米技术中采用低压运行的视觉芯片的脉冲域数字图像处理
DOI：
10.1109/jstqe.2004.833888
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发表时间：
2004
影响因子：
4.9
通讯作者：
M. Nunoshita
中科院分区：
文献类型：
--
作者：
K. Kagawa;Koutaro Yasuoka;D. C. Ng;T. Furumiya;T. Tokuda;J. Ohta;M. Nunoshita
提出了一种用于CMOS视觉芯片脉冲域像素级并行图像处理的新架构。基于数字脉冲的抑制和增强，实现了边缘增强、边缘检测和模糊等图像处理；像素值由使用脉冲频率调制（PFM）光敏器或使用像素内1位模数转换器的数字脉冲的频率表示。由于图像处理是由具有少量逻辑门的1位全数字电路实现的，因此所提出的架构适用于深亚微米技术的低压操作。讨论了图像处理的原理。我们制作了一个16 /spl倍/ 16像素的原型视觉芯片。描述了光照与输出脉冲频率之间的关系。在基本图像处理操作中，原型视觉芯片的阶跃响应与基于相关空间滤波的期望相吻合。本文还提出了一种简单的图像二值化方法。图像处理后输出脉冲间隔的直方图显示出多个峰值，这表明为了获得更高的图像处理质量，需要对间隔进行更长时间的平均。为了提高脉冲频率对光照的线性依赖性，讨论了随机时钟的使用。
A new architecture for pixel-level parallel image processing in the pulse domain for CMOS vision chips has been developed. Image processing such as edge enhancement, edge detection, and blurring are realized based on suppression and promotion of digital pulses; the pixel value is represented by the frequency of digital pulses by use of a pulse-frequency modulation (PFM) photosensor or that with an in-pixel 1-bit analog-to-digital converter. The proposed architecture is suitable for low-voltage operation in deep-submicrometer technologies because the image processing is implemented by 1-bit fully digital circuits with a small number of logic gates. The principles of the image processing are addressed. We have fabricated a 16 /spl times/ 16-pixel prototype vision chip. The relationship between illumination and the output pulse frequency is characterized. Step responses of the prototype vision chip for fundamental image processing operations show good agreement with those expected by correlation-based spatial filtering. A simple image binarization method specific to our architecture is also presented. The histograms of the intervals of the output pulses after image processing show multiple peaks, which indicates that averaging of the intervals is required for longer periods to achieve higher image-processing quality. To improve the linearity of pulse frequency dependence on illumination, usage of random clocks is discussed.
DOI：
10.1109/isscc.1999.759263
发表时间：
1999-02
期刊：
--
影响因子：
--
作者：
David X. D. Yang;A. Gamal;B. Fowler;H. Tian
通讯作者：
David X. D. Yang;A. Gamal;B. Fowler;H. Tian