高图像配准精度的非相干数字全息彩色成像

Incoherent digital holographic color imaging with high accuracy image registration

菲涅耳非相干相关全息是一种能记录非相干物体全息图的新型技术,在生物医学成像和三维遥感领域具有重要应用前景。针对高光谱成像过程中图像融合配准困难的问题,文中利用空间光调制器的可编程特性,设计并制作了波长分别为492、562、672 nm的三组焦距恒定的双透镜相位掩模,依次调用三种波长的掩模并记录对应波长下物体的全息图。由于三色记录光经对应波长掩模调制后在CCD表面汇聚的光斑位置及尺寸均相同,因此,全息图重建后获得的重建图像具有相同的横向放大率,可提高图像融合时的配准精度,免去繁杂的光谱图像空间配准算法,真正实现了全息彩色成像的高精度配准和实时融合。采用该系统记录骰子的全息图,经数值重建及色彩融合后得到了颜色重建性较好的彩色三维像。

Fresnel incoherent correlation holography is a new technology which can record incoherent object holograms and has important applications in biomedical imaging and 3D remote sensing. The problem of image fusion registration in hyperspectral imaging, three groups of double lens phase masks with constant focal lengths at 492 nm, 562 nm and 672 nm were designed and fabricated. The spatial light modulator called the masks of three wavelengths in turn and recorded the holograms of the objects under the corresponding wavelengths, which owed to the spatial light modulator were programmable. Because of the three-color recorded light was modulated by the corresponding wavelength mask, the spot position size of the CCD surface was the same. The reconstructed images had constant lateral magnification, which could improve the image registration accuracy and avoid complicated spatial registration algorithm of spectral images. The system truly achieved high-precision registration and real-time fusion of holographic color imaging. The color 3D image obtained from the dice holograms had high color reconstruction after numerical reconstruction and color fusion.