提出一种基于离散衍射光的全息光栅的带宽压缩算法。人眼的视觉分辨率是有限的,即空间频率变化在Δfpupil以内时(两根光线的夹角小于0.3°),不会察觉光线的跳变。首先对衍射光的频谱进行采样,使全息光栅衍射的是空间频率不连续的离散光,即在光栅的编码中只包含离散光频谱,且满足人眼视觉要求。这样,光栅的条纹函数为周期性函数,因此,在条纹编码中我们只需记录一个周期的函数值(样本数),光栅的条纹函数的样本数可得到有效的压缩。然后在解码中通过简单的复制可恢复光栅条纹函数的全部样本值。采用这种方法,大大压缩了数据量,提高了传输速率,达到了动态显示的要求。

Based on discrete diffraction light, an algorithm of holographic grating bandwidth compression is proposed. As is known to all, the visual resolution of human eyes is quite limited. That is, human eyes cannot perceive the jump of light beams within the 8 mm-1 variation of space frequency (angle between two light beams is less than 0.30°). At first the frequency spectrum of diffraction light is sampled so as to make holographic grating diffraction discrete in space frequency, namely, in the grating code is included discrete frequency spectrum, which satisfies requirements of human vision. In this case, the fringe function of the grating becomes a periodic one, and what is needed, therefore, is to record a periodic functional value (sampling value). As a result, the sampling value of such fringe function can be effectively compressed. Subsequently, all sampling values of the fringe function can be restored in decoding right by means of copying. This method that can not only compress data but also upgrade transmission rate achieves the desired dynamic display.