Abstract Diabetic macular edema (DME) can appear in any stage of the diabetic retinopathy (DR) and is the leading cause of vision impairment in people with diabetes. Therefore, the automatic analysis of DME plays a key role in the DR screening program. According to the DME international clinical classification standard, detecting and judging the presence of hard exudates (HEs) close or relate to macula fovea (MF) is a standard method to assess DME in the fundus images. A synthetic improvement method based on existing mathematical morphology technique is selected for HEs detection. A novel method of macular fovea center location is proposed based on the directional local contrast filter and the local vessel density. Then the optic disk region can be easily located and removed for reducing the impact to the HEs detection. Only the large vessel segmentations were used for the vessel density calculation. From the testing results on the 169 images from HEIMED public dataset, the sensitivity and specificity of HEs detection on image level are 100% and 922%, respectively. The accuracy of macular fovea center location reaches 982%. And the accuracy for each DME classification is more than 88%. The proposed method would have important clinical application potentials.
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