An image fusion algorithm based on discrete cosine transform (DCT) and an image fusion scheme using wavelet transform combined with DCT were proposed. The former based on DCT fused the corresponding areas of the original images according to the DCT coefficient high frequency energy and the latter using wavelet transform and DCT fused the low frequency submaps by use of DCT coefficient high frequency energy. The wavelet high frequency coefficients of the highest wavelet decomposition level were decided by the wavelet low frequency coefficients. The wavelet high frequency coefficients of the other wavelet decomposition levels were selected with the greater local deviation. The fused images of the algorithms purposed were evaluated by some parameters such as average error
peak signal noise rate
and root mean square error
compared with other conventional image fusion methods based on wavelet transform or DCT. The experimental results show that the new algorithm based on wavelet transform combined with DCT provides the best performance with 40.8% to 69.5% reduction in average error
9.9% to 15.6% improvement of peak signal noise rate and 34.8% to 47.5% reduction in root mean square error. It is superior to the conventional methods using wavelet transform. This algorithm improves the quality of the fused image effectively
the evaluation results coincide with the visual effect very well. The algorithm based on DCT needs less computational burden and is more suitable for the real-time processing.
关键词
Keywords
references
. ZHANG ZH, BLUM R S. A Categorization of multiscale-decomposition-based image fusion schemes with a performance study for a digital camera application[J]. Proceedings of the IEEE, 1999, 87(8): 1315-1326.
. LI H, MANJUNATH B S, MITRA S K. Multisensor image fusion using the wavelet transform[J]. Graphical Models and Image Processing, 1995, 57(3):235-245.
. PAJARES G, CRUZ J M. A wavelet-based image fusion tutorial[J]. Pattern Recognition, 2004, 37(9): 1855-1872.
. 陈洪波,王强,张孝飞,等. 基于小波系数邻域特征的图像融合[J]. 光学 精密工程, 2003, 11(5): 516-522. CHEN H B, WANG Q, ZHANG X F, et al. Image fusion based on neighborhood features of wavelet coefficients[J]. Optics and Precision Engineering, 2003, 11(5): 516-522. (in Chinese)
. 孙辉. 基于小波变换的图像数据融合方法[J]. 光学 精密工程, 2000, 8(6): 551-553. SUN H. Data fusion for image based on wavelet transform[J]. Optics and Precision Engineering, 2000, 8(6): 551-553. (in Chinese)
. 刘艳,李宏东. DCT域图象处理和特征提取技术[J]. 中国图象图形学报, 2003, 8(2): 121-128. LIU Y, LI H D. Image and video processing techniques in the DCT domain[J]. Journal of Image and Graphics, 2003, 8(2): 121-128. (in Chinese)
. JIANG J M, FENG G C. The spatial relationship of DCT coefficients between a block and its sub-blocks[J]. IEEE Transactions on Signal Processing, 2002,50(5): 1160-1169.
. TANG J SH. A contrast based image fusion technique in the DCT domain . Digital Signal Processing, 2004, 14(3): 218-226.
. 吴乐南. 数据压缩[M]. 北京:电子工业出版社, 2000. WU L N. Data compression[M]. Beijing: Publishing House of Electronics Industry, 2000. (in Chinese)
. 谢攀, 张利, 康宗明, 等. 一种基于尺度变化的DCT自动聚焦算法[J]. 清华大学学报(自然科学版), 2003, 43(1): 55-58. XIE P, ZHANG L, KANG Z M, et al. Window scale-based automatic focus algorithm using DCT transformation[J]. Journal of Tsinghua University (Science & Technology), 2003, 43(1): 55-58. (in Chinese)
. MALLAT S G. A Theory for multiresolution signal decomposition: the wavelet representation[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence, 1989,11(7): 674-693.
. MALLAT S G. Multifrequency channel decompositions of images and wavelet models[J]. IEEE Transactions on Acoustics. Speech. and Signal Processing, 1989, 37(12): 2091-2110.
. 强赞霞,彭嘉雄,王洪群. 基于小波变换局部方差的遥感图像融合[J]. 华中科技大学学报(自然科学版), 2003, 31(6): 89-91. QIANG Z X, PENG J X, WANG H Q. Remote sensing image fusion based on local deviation of wavelet transform[J]. Journal of Huazhong University of Science and Technology (Nature Science Edition), 2003, 31(6): 89-91. (in Chinese)
. 李树涛,王耀南,龚理专. 多聚焦图像融合中最佳小波分解层数的选取[J]. 系统工程与电子技术,2002,24(6): 45-48. LI SH T, WANG Y N, GONG L ZH. Selection of optimal decomposition level of wavelet for multifocus image fusion[J]. Systems Engineering and Electronics, 2002, 24(6): 45-48. (in Chinese)
. 陈木生,狄红卫. 多聚焦图像融合的最佳小波分解层研究[J]. 光电工程,2004,31(3): 64-67. CHEN M SH, DI H W. Study on optimal wavelet decomposition level for multi-focus image fusion[J]. Opto-Electronic Engineering, 2004, 31(3): 64-67. (in Chinese)