Image Fusion by a Visual Threshold Based Pyramid

A visual theshold based pyramid image fusion method is proposed after the Laplacian pyramid method and rate-of-low-pass pyramid method were analyzed and compared.It adopts the following fusion strategy: when the targets from different source images are above their individual thresholds and their contrast polarities are found to be identical,the corresponding fused elements are determined according to contrast information;otherwise,the fused elements are determined according to absolute difference values.The results showed that the contrast information of fused images can be enhanced and the speckle noise frequently incurred in the rate-of-low-pass pyramid method can be avoided at the same time.Its extra computational load is not significant,so the method is suitable for use in some real-time fusion fields.