Optical line tweezers have been an efficient tool for the manipulation of large micron particles. In this paper, we propose to create line traps with transformable configurations by using the transverse electromagnetic mode-like laser source. We designed an optical path to simulate the generation of the astigmatic beams and line traps with a series of lenses to realize the rotational transformation with respect to the rotation angle of cylindrical lenses. It is shown that the spherical particles with diameters ranging from 5 μm to 20 μm could be trapped, aligned, and revolved in experiment. The periodical trapping forces generated by transformable line traps might open an alternative way to investigate the mechanical properties of soft particles and biological cells.

基于可变形模型的目标跟踪算法因其能够处理目标部分遮挡及形变问题成为目标跟踪领域的研究热点。当目标发生形变或部分遮挡时，可变形模型跟踪器可利用未被遮挡的子块继续完成跟踪。现有基于子块的目标跟踪算法均为手动选取子块的个数和尺寸，但在实际应用中，很难为子块的选取提供人机交互的机会，且手动选取子块易受主观因素影响。针对上述情况，提出了一种采用多特征融合的子块自动提取方法，该方法首先采用基于人眼视觉注意机制对目标模板的显著性区域进行度量；其次，利用边缘方向离散度对目标的纹理丰富度进行度量；然后，融合上述特征获得联合适配性置信度，并根据目标的面积和宽高比自适应确定子块的个数和尺寸；最后，根据联合适配性置信度提取目标子块。实验结果表明，与现有手动选取子块的可变形模型目标跟踪方法相比，采用所提方法自动提取的子块可获得更高的跟踪精度。