this paper presents an automated method for detecting microaneurysms in the retinal angiographic images by using image processing techniques. in the presented method, in order to fade or remove the pseudo images, first retinal images are pre-processed. then microaneurysms are identified by circular hough transform. in the existing methods of detecting microaneurysms, it is necessary to identify...

optical coherence tomography (oct) is a powerful imaging modality used to image various aspects of biological tissues, such as structural information, blood flow, elastic parameters, change of polarization states, and molecular content [1]. in contrast to oct technology development which has been a field of active research since 1991, oct image segmentation has only been more fully explored dur...

Diabetic retinopathy lesion detection such as exudate in fundus image of retina can lead to early diagnosis of the disease. Retinal image includes dark areas such as main blood vessels and retinal tissue and also bright areas such as optic disk, optical fibers and lesions e.g. exudate. In this paper, a multistage algorithm for the detection of exudate in foreground is proposed. The algorithm se...

In medical image processing, retinal image enhancement is the challenging issue to reveal the unseen details of an retinal image, thus, in many applications image enhancement issued to solve the challenges such as, noise reduction, blurring, degradation, etc. To improve the visual grade of retinal images we have many alternative image enhancement techniques that are suitable for specific applic...

The RGB color retinal image has an interesting characteristic, i.e. the G channel contains more important information than the other ones. One of the most important features in a retinal image is the retinal blood vessel structure. Many diseases can be diagnosed based on in the retinal blood vessel, such as micro aneurysms that can lead to blindness. In the G channel, the contrast between retin...

Retinal image slip promoted by fixational eye movements prevents image fading in central vision. However, in the periphery a higher amount of movement is necessary to prevent this fading. We assessed the effect of different levels of retinal image slip in peripheral vision by measuring peripheral visual acuity (VA), with and without crowding, while modulating retinal image slip by using gaze-li...

distribution of retinal blood vessels (rbvs) in retinal images has an important role in the prevention, diagnosis, monitoring and treatment of diseases, such as diabetes, high blood pressure, or heart disease. therefore, detection of the exact location of rbvs is very important for ophthalmologists. one of the frequently used techniques for extraction of these vessels is region growing-based se...