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摘要: 针对目前图像融合过程中的不足之处,结合有限离散剪切波具有高的方向敏感性和抛物尺度化特性,提出了一种有限离散剪切波变换下的图像融合算法。首先对严格配准的多传感器图像进行有限离散剪切波变换,得到低频子带系数和不同尺度不同方向的高频子带系数;然后对低频子带系数采用全局特征值和像素点之间的差异性与区域空间频率匹配度相结合的融合算法,高频方向子带系数采用方向权重对比度与相对区域平均梯度和相对区域方差相结合的方案;最后通过有限离散剪切波逆变换得到融合图像。实验结果表明,与其他的融合算法相比较,本文算法不但有良好的主观视觉效果,而且3幅图像的客观评价指标分别平均提高了0.9%、3.8%、3.1%,2.6%、3.8%、2.9%和1.5%、125%、59%,充分说明了本文融合算法的优越性。Abstract: Aiming at the deficiency of the current image fusion process, combining with good directional sensitivity and parabolic scaling properties of Finite Discrete Shearlet Transform(FDST), a new image fusion algorithm based on FDST is proposed. Firstly, the registration multi sensing images are decomposed by FDST, and the low frequency sub-band coefficients and high frequency sub-band coefficients of different scales and directions are obtained. The fusion principle of low frequency sub-band coefficients is based on the method of combining the differences between global attribute and each pixel with region spatial frequency matching degree. As for high frequency sub-band coefficients, sum of the directional weight contrast can be adopted as the fusion rule, which combines with the relative region average gradient and relative region variance. Finally, the low frequency information and high frequency information are reconstructed to image by Finite Discrete Shearlet Inverse Transform. The results indicate that the algorithm proposed in this paper has a good subjective visual effect, and its quality indexes has been increased averagely by 0.9%、3.8%、3.1%, 2.6%、3.8%、2.9% and 1.5%、125%、59% respectively compared with other fusion algorithms, which shows that the algorithm is superior to other fusion algorithms.
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Key words:
- image fusion /
- finite discrete shearlet /
- contrast /
- regional average gradient /
- shift-invariant
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表 1 不同小波域下对红外与可见光图的融合结果比较
Table 1. Fusion results comparison of infrared and visible image in different wavelet domain
Fusion evaluation Infrared and visible image Average running time/s EN MI QAB/F SWT 5.648 1 1.618 8 0.389 4 2.246 5 DWT 5.412 3 1.521 5 0.501 8 2.487 4 NSCT 5.216 5 1.741 1 0.391 1 2.798 1 DTCWT 5.348 9 1.815 6 0.384 1 2.741 6 NSST 5.481 4 1.815 4 0.377 5 3.146 7 FDST 6.841 2 3.924 8 0.661 4 2.194 5 表 2 不同小波域在不同融合策略下对红外与可见光图的融合结果比较
Table 2. Fusion results comparison of infrared and visible by using different fusion strategies in different wavelet domain
Fusion evaluation Infrared and visible image(5) Infrared and visible image(6) Infrared and visible image(7) Averagerunning time/s EN MI QAB/F EN MI QAB/F EN MI QAB/F NSST_ HSGLRV 6.825 8 3.038 8 0.447 9 7.231 7 3.152 2 0.605 3 7.432 1 2.439 2 0.548 8 10.457 9 FRWT_HRELV 6.732 3 3.749 1 0.417 8 7.132 7 2.828 2 0.423 4 7.287 8 2.686 1 0.353 9 8.407 3 FDST_LGHRS 6.924 7 2.123 0 0.474 3 7.490 1 2.511 0 0.646 9 7.413 0 3.746 4 0.686 4 9.432 7 FDST_LGVHC 7.000 8 3.870 4 0.573 2 7.349 2 3.868 5 0.708 0 7.487 2 6.460 0 0.781 7 6.228 8 -
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