Multi-focus image fusion with the double-density dual-tree DWT

This paper presents a novel multi-focus image fusion based on a double-density dual-tree discrete wavelet transform. The original image is decomposed into the 16-subband image pyramid by this wavelet. The image fusion process is performed by the direction value and the region standard deviation to get the fused 16-subband image pyramid. The final fused image is formed with the 16-subband image reconstruction. The fusion experiments indicate this image fusion is superior to the traditional image fusion based on the contrast pyramid or the wavelet decomposition.