Algorithm 1: An image fusion algorithm based on PCNN and SFLA
Input: A SPECT image A and a CT image B
Output: A fused image F
Step 1: Obtain three components of image A using IHS transform; saturation S, hue H and intensity I.
Step 2: Image decomposition
(1) Decompose the component I of image A to a low-frequency image AL and high-frequency image AH through NSCT decomposition.
(2) Decompose image B to a low-frequency image BL and high-frequency image BH through NSCT decomposition.
Step 3: Image fusion
(1) Fuse the low-frequency images AL and BL to a new low-frequency image CL through the SFLA and PCNN combination fusion rules.
(2) Fuse the high-frequency images AH and BH to form a new high-frequency image CH through the SFLA and PCNN combination fusion rules.
Step 4: Inverse transform
Fuse the low-frequency image CL and high-frequency image CH to a new image with intensity I’ using reversed NSCT.
Step 5: Reversed IHS transform
Through the reversed IHS transform, integrate the three components S, H and I’, then obtain the target image F.