An effective wavelet-based scheme for multi-focus image fusion

Conventional methods of multi-focus image fusion have high computation and cause blocking effect or artificial effect easily. An effective multi-focus image fusion scheme based on the lifting scheme of wavelets is proposed in this paper. The pending images are decomposed by using the wavelet lifting scheme into four subbands firstly: LL, LH, HL, HH, and then subband LH, HL, HH, are synthesized to obtain three directions of high-frequency details of the images. The local luminance contrast, which is represented by weighted region energies, is calculated by the Gaussian kernel based on the high-frequency details. Thus the energy-based image fusion rule is applied to get a binary map by choosing the maximum energy between images. The performance of the proposed multi-focus image fusion scheme is compared with the existing methods by different function evaluation criteria. Experimental results show that the proposed method has a significant improvement of the fused image with no blocking effect or artificial effect. The proposed method performs the best in trade-offs in image processing speed and the quality of fused image comparing with conventional methods.