A new method for retinal fundus image enhancement

Abstract:

Objective：To improve the visual effect of the vessels and lesion sites in fundus image and to contribute to clinical diagnosis. Methods：Firstly，mathematical morphology was used to weaken the background so as to preliminary enhance the image. Then，contrast limited adaptive histogram equalization was performed to adjust the uneven brightness in the images. Finally，two-dimensional matched filters were exploited to strengthen vessels and pathological regions and improve the contrast between background and ves－sels. Results：Result showed that the proposed method can efficiently weaken background and enhance contrast. Regions of interest were improved significantly；vessels segmentation in optic disk regions and identification of pathological region became much easier. Conclusion：Proposed enhancement method can be applicable to normal retinal images as well as pathological retinal images，which is useful for clinical diagnosis.