Infrared image enhancement based on generalized linear operation and bilateral filter

As classical infrared image enhancement methods based on Unsharp Masking(UM)suffer from terrible noise interference and halo effect,a new approach based on generalized linear operation and Bilateral Filtering(BF)was proposed here.Firstly,the elemental part of the image was extracted by using the BF and then operation models based on generalized linear operation were designed for the following enhancement.In the new operation scheme,the image details were nonlinearly segmented,denoised and amplified and the dynamic range of the elemental part was compressed while the detailed part was enhanced adaptively.Finally,the enhanced image was obtained by adding the processed elemental and detailed parts together nonlinearly.Furthermore,an assessment method for image quality was presented.Unlike the classical metric which only considers the average contrast enhancement,the modified one involves both local and general average contrast enhancements.Both the comparison experiments and measurement index indicate that the proposed method can compress the dynamic range of infrared images,amplify their details,and suppress the noise interference and halo effect.This technique has a significant contribution to the posterior image processing of thermal infrared cameras.