It is valuable to merge the green fluorescent protein (GFP) fluorescent image and its corresponding phase contrast image for the localization of the protein and sub-cellular structures. When ARSIS concept based methods which have been successfully applied to merge remote sensing images are used for the fusion of GFP fluorescent and phase contrast images

there may exist many artifacts. To overcome this limit

a variable-transparency concept is proposed to design a set of functions based on visual effects. After each pixel is assigned the multi-scaled transparency

original images can be synthesized from their results of stationary wavelet transform (SWT). Firstly 30 groups of images are used to estimate parameters involved in the function set and then 117 groups are assessed by means of qualitative tests. Quantified indexes which are related with the fused product and original images

such as the quality index Q and the high frequency correlation coefficient HPCC

are respectively calculated for inside and outside of the fluorescent area. Results demonstrate that compared with common algorithms

including the transparency method

the chessboard method and the SWT substitution method

this proposed algorithm can keep the interactive user-transparency and improve the definition of the fused product while reduce the interruption from the dark background of fluorescent images.