For processing multi-band infrared images detected by Multi-color IR Focal Plane Arrays (IRFPA), an image fusion
algorithm is proposed based on contourlet transform (CT). Source images are firstly decomposed to the domain of the
contourlet transform, the image fusion is then implemented in sub-bands with different scales and directions combining
with special image fusion rules. By employing the parameters of Regional Energy (RE) and Local Relative Pixel
Intensity (LRPI), which are calculated with the values of CT coefficients and the corresponding neighbor region, the
algorithm integrates the approximation coefficients and the detail coefficients according to the parameters. Evaluations
of the experiment results according to both the subjective and objective criteria, including average, mean square error,
entropy and combined entropy, demonstrate that the algorithm based on CT with the proposed fusion rules is more
effective than the ones based on CT with RE fusion rules and traditional method.
In this paper, a novel method is proposed to implement Laplacian pyramid image fusion on FPGA. Firstly,
implementation of image fusion algorithm based on Programable DSP (PDSP) and FPGA is compared, as well as the
advantages of Laplacian pyramid for parallel processing. Secondly, the architecture and characters of Laplacian pyramid
is analyzed in detail. Finally the related logical modules in FPGA are designed according to their functions of this
algorithm, including controlling module, decomposing module, fusion module and reconstruction module. Inside the
decomposing module, 3-stage pipeline is designed for decomposing images at each level. Three-level Laplacian pyramid
image fusion algorithm is adopted through Verilog Hardware Description Language according to the designed methods
forementioned. The design is verified on a real-time dual-channel image fusion system based on Virtex-4 SX35 FPGA.
The experiment results show that the fusion system can realize real-time image fusion processing for dual channels
640×480 images at the rate of 25 frames per second. Comparing with input digital video stream, the output video stream
delays less than 10 horizontal line clocks.