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FA and SLO images of 21 subjects with diabetic retinopathy captured via Heidelberg Spectralis HRA2/OCT device

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This dataset contains 36 pairs of FA and SLO images of 21 subjects with diabetic retinopathy in jpg format are captured via Heidelberg Spectralis HRA2/OCT device and used for automatic registration. FA images were captured with two different fields of views (30 and 55 degrees).

Accurate and automatic registration of multimodal retinal images enables utilization of supplementary information. Due to differences in contrast, resolution and brightness of multimodal retinal images, the images resulted from vessel extraction of image pairs are not exactly the same. Also, prevalent feature detection, extraction and matching schemes do not result in perfect matches. In addition, the relationships between retinal image pairs are usually modeled by affine transformation, which cannot generate accurate alignments due to the non-planar retina surface. In this paper, a precise registration scheme is proposed to align FA and OCT images via scanning laser ophthalmoscopy (SLO) photographs as intermediate images. For this purpose, first a retinal vessel segmentation is applied to extract main blood vessels from the FA and SLO images. Next, a novel global registration is proposed based on the Gaussian model for curved surface of retina. For doing so, first a global rigid transformation is applied to FA vessel-map image using a new feature-based method to align it with SLO vessel-map photograph, in a way that outlier matched features resulted from not-perfect vessel segmentation are completely eliminated. After that, the transformed image is globally registered again considering Gaussian model for curved surface of retina to improve the precision of the previous step. Eventually a local non-rigid transformation is exploited to register two images perfectly. The experimental results indicate the presented scheme is more precise compared to other registration methods.

Please reference the following paper if you would like to use any part of this dataset or method:

Almasi, R., Vafaei, A., Ghasemi, Z., Ommani, M. R., Dehghani, A. R., & Rabbani, H. (2020). Registration of fluorescein angiography and optical coherence tomography images of curved retina via scanning laser ophthalmoscopy photographs. Biomedical Optics Express11(7), 3455-3476.