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。
Homomorphic filtering is a frequency domain operation to compress image light area 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。
The results indicated that five of them have suitable spectra and light transmissivity decreased in UV-light area but keep above 85% in visible light area, which we've expected before.结果表明,其中有几种薄膜光谱匹配性较好,与空白对照膜相比,紫外光的透光率降低,但可见光透光率都在85%以上。