Infrared image enhancement through contrast enhancement by using multiscale new top-hat transform

Infrared imaging sensor is sensitive to the variation of imaging environment, which may affect the quality of the obtained images and blur the regions of interest in infrared image. So, it is very important to enhance infrared image. In infrared image, the gray values of the regions of interest are bright or dim image regions, which are different from the surrounding regions. The new top-hat transform could extract image regions which are different from its surrounding regions. In light of this, an infrared image enhancement algorithm through contrast enhancement is proposed in this paper based on multiscale new top-hat transform. Firstly, the multiscale white and black new top-hat transforms are used to extract the multiscale light and dark infrared image regions. Then, the final light and dark infrared image regions for image enhancement are constructed by using the extracted multiscale light and dark infrared image regions. Finally, the contrast of the infrared image is enhanced through a power strategy. Experimental results on different infrared images show that the proposed algorithm could well enhance infrared image and make the possible interested targets brighter, which is very helpful for target detection and recognition.

Research highlights
► An algorithm based on multiscale new top-hat transform is proposed to well enhance infrared image.
► New top-hat transform reasonably extracts the light and dark image regions for infrared image enhancement.
► The contrast between the regions of interest and surrounding regions is apparently enhanced.
► The proposed algorithm could effectively enhance infrared image, especially the image with dim target regions.