It considers edge points and dark or lightarea when embedding watermark information.
在嵌入水印信息时先考虑边缘点，再考虑亮度较暗和较亮区域。
2
Homomorphic filtering is a frequency domain operation to compress image lightarea and enhance contrast.
同态滤波是一种将亮度范围压缩和对比度增强的频域处理方法。
3
The results indicated that five of them have suitable spectra and light transmissivity decreased in UV-lightarea but keep above 85% in visible lightarea, which we've expected before.