基于Gabor局部和全局特征的凸字符识别

来源 :ChineseOpticsLetters | 被引量 : 0次 | 上传用户:yndlyxb
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Conventional Gabor representation and its extracted features often yield a fairly poor performance in extracting the invariance features of objects. To address this issue, a global Gabor representation method for raised characters pressed on label is proposed in this paper, where the representation only requires few summations on the conventional Gabor filter responses. Features are then extracted from these new representations to construct the invariant features. Experimental results clearly show that the obtained global Gabor features provide good performance in rotation, translation, and scale invariance. Also, they are insensitive to illumination conditions and noise changes. It is proved that Gabor filters can be reliably used in low-level feature extraction in image processing and the global Gabor features can be used to construct robust invariant recognition system.
其他文献
An efficient channel estimation method called time-domain weighted average (TWA) algorithm is proposed for coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. On the premise of calculating the associated weight of channel transf
期刊
1970年初连续抽运锁模染料激光器的研究使1974年第一个亚微微秒光脉冲产生成为可能。在七十年代的后来几年中,试图产生更短的光脉冲实际上没有特别的成就。去年年初报导的两个新成果现已由贝尔实验室的一个小组用来产生仅30毫微微秒的光脉冲,即3×10-14秒或14个6200埃红光周期的光脉冲。
期刊
期刊
An asynchronous optical sampling scheme based on four-wave mixing (FWM) in highly nonlinear fiber (HNLF) is experimentally demonstrated. Based on this scheme, 10-GHz input pulse train with 1.8-ps pulse width is successfully sampled in 100-m HNLF. A single
利用分子动力学模型模拟出单个脉冲作用后的热传导过程, 并得到了在下个脉冲辐照前硅材料表面的温度变化情况, 深入探究了非辐射复合及表面浮雕结构对硅表面温度的影响, 并根据分子动力学方程数值模拟了多脉冲飞秒激光烧蚀硅材料的超快热响应, 分析了电子与晶格的瞬态热平衡和硅表面最大温度随俄歇复合的变化。针对硅材料加工领域中高频多脉冲持续扫描硅表面的情况, 建立了宏观加热机制, 以减轻加工过程中的热累积效应。当采用较高重频脉冲时, 宏观热模型计算结果表明多脉冲扫描硅表面时, 温度的热积累不仅与光源本身入射通量和重频有
加里弗尼亚州门洛·帕克消息:此地的斯坦福研究所发展的一种光激射器雷达已达到6.9~7.6兆瓦, 20~30毫米宽度 峰値脉冲。这样高的脉冲功率的成功取得是因为釆用了高速转动棱镜的Q开关, 其转数达30,000~60, 000转/分。仪器由加里福尼亚州散卡洛斯的贝克曼和威特利公司(Beckman
期刊
飞秒激光在工业加工、精密测量、军事国防、科学研究等领域具有广阔的应用前景。报道了基于光谱控制与色散优化的高功率、高脉冲质量飞秒啁啾脉冲放大系统。利用与压缩器色散量相匹配的色散可调啁啾布拉格光纤光栅(CFBG)作为展宽器,通过微调CFBG色散量补偿系统的残余色散使整个系统的净色散趋于零;同时引入光谱滤波等手段,保证入射到主放大器之前的脉冲光谱形状不发生畸变,避免了放大过程中脉冲质量的劣化。最终获得了重复频率为50 MHz、平均功率为24 W、脉冲宽度为198 fs的高脉冲质量飞秒激光输出。
We propose some new schemes to constitute two-dimensional (2D) array of multi-well optical dipole traps for cold atoms (or molecules) by using an optical system consisting of a binary 'pi'-phase grating and a 2D array of rectangle microlens. We calculat
期刊