Chen Huanping, He Mingyi, li Xu. Multi-focus image fusion using pixel extraction based on SWT regional contrast[J]. Journal of Image and Graphics, 2011, 16(5): 865-870. DOI: 10.11834/jig.20110520.
the multi-resolution coefficients fusion algorithms can not extract the clear pixels from source images
and the block extract algorithms always cause block effects. Therefore
the authors define the image pixels’ regional contrast based on stationary wavelet transform (SWT)
which is non-subsampled and translation invariant
considering the characteristics of the clear pixels in multi-focus images and the contrast features of human visual system. On the basis of studying how different neighborhood sizes of regional contrast can affect the correctness of extracted pixels
a proper threshold is set to build extraction templates
which are used to extract pixels in the clear region in source images. Then
the method of image fusion based on local energy mechanism is applied to those un-extracted pixels. The experimental results illustrate the novel algorithm in the paper can not only effectively extract the clear pixels from source images
but also reduce the block effects greatly
and the quality of the fused image is improved sharply.