Aiming at the characteristics of low visible light images and infrared images, a novel adaptive image fusion scheme based on DT-CWT was presented. The technique has good shift-invariance and directional selectivity, and is more suitable for human vision. The DT-CWT was firstly used to perform a muhiresolution decomposition of source images. By taking advantage of the characters of the coefficients, the immune clonal selection algorithm was introduced in low-pass subbands and almost optimal fused weights were obtained adaptively. To high-pass subbands, the local directive contrast was defined, which was based on human visual system. And then the contrast of fused images was enhanced and the detail information of source images was protected. The experimental results show that our fused technique is effective and the fused images have a better visual quality than their wavelet counterparts.