Automated diabetic macular edema (DME) grading system using DWT, DCT Features and maculopathy index.
The cause of diabetic macular edema (DME) is due to prolonged and uncontrolled diabetes mellitus (DM) which affects the vision of diabetic subjects. DME is graded based on the exudate location from the macula. It is clinically diagnosed using fundus images which is tedious and time-consuming. Regular eye screening and subsequent treatment may prevent the vision loss. Hence, in this work, a hybrid system based on Radon transform (RT), discrete wavelet transform (DWT) and discrete cosine transform (DCT) are proposed for an automated detection of DME. The fundus images are subjected to RT to obtain sinograms and DWT is applied on these sinograms to extract wavelet coefficients (approximate, horizontal, vertical and diagonal). DCT is applied on approximate coefficients to obtain 2D-DCT coefficients. Further, these coefficients are converted into 1D vector by arranging the coefficients in zig-zag manner. This 1D signal is subjected to locality sensitive discriminant analysis (LSDA). Finally, various supervised classifiers are used to classify the three classes using significant features. Our proposed technique yielded a classification accuracy of 100% and 97.01% using two and seven significant features for private and public (MESSIDOR) databases respectively. Also, a maculopathy index is formulated with two significant parameters to discriminate the three groups distinctly using a single integer. Hence, our obtained results suggest that this system can be used as an eye screening tool for diabetic subjects for DME.
Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore 599489, Singapore; Department of Biomedical Engineering, School of Science and Technology, SIM University, Singapore 599491, Singapore; Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603, Malaysia.
U Rajendra
UR
Acharya
Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore 599489, Singapore. Electronic address: mrk2k2@gmail.com.
Muthu Rama Krishnan
MRK
Mookiah
Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore 599489, Singapore.
Joel E W
JEW
Koh
Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore 599489, Singapore.
Jen Hong
JH
Tan
Department of Ophthalmology, Kasturba Medical College, Manipal 576104, India.
Sulatha V
SV
Bhandary
Department of Ophthalmology, Kasturba Medical College, Manipal 576104, India.
A Krishna
AK
Rao
Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore 599489, Singapore.
Yuki
Y
Hagiwara
Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore 599489, Singapore.
Chua Kuang
CK
Chua
National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore 308433, Singapore.
Augustinus
A
Laude
D000328:Adult; D000368:Aged; D000465:Algorithms; D003930:Diabetic Retinopathy / Q000000981:diagnostic imaging*; D016002:Discriminant Analysis; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008269:Macular Edema / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D058067:Wavelet Analysis
Decision support system; Diabetic macular edema; Discrete cosine transform; Discrete wavelet transform; Fundus imaging; Locality sensitive discriminant analysis; Radon transform