Title
Assessment of computational visual attention models on medical images
Abstract
Several computational visual saliency models have been proposed in the context of viewing natural scenes. We aim to investigate the relevance of computational saliency models in medical images in the context of abnormality detection. We report on two studies aimed at understanding the role of visual saliency in medical images. Diffuse lesions in Chest X-Ray images, which are characteristic of Pneumoconiosis and high contrast lesions such as 'Hard Exudates' in retinal images were chosen for the study. These approximately correspond to conjunctive and disjunctive targets in a visual search task. Saliency maps were computed using three popular models namely Itti-Koch [7], GBVS [3] and SR [4]. The obtained maps were evaluated against gaze maps and ground truth from medical experts. Our results show that GBVS is seen to perform the best (Mdn. ROC area = 0.77) for chest X-Ray images while SR performs the best (ROC area = 0.73) for retinal images, thus asserting that searching for conjunctive targets calls for a more local examination of an image while disjunctive targets call for a global examination. Based on the results of the above study, we propose extensions for the two best performing models. The first extension makes use of top down knowledge such as lung segmentation. This is shown to improve the performance of GBVS to some extent. In the second case the extension is by way of including multi-scale information. This is shown to significantly (by 28.76%) improve abnormality detection. The key insight from these studies is that bottom saliency continues to play a predominant role in examining medical images.
Year
DOI
Venue
2012
10.1145/2425333.2425413
ICVGIP
Keywords
Field
DocType
computational saliency model,disjunctive target,computational visual saliency model,medical expert,abnormality detection,retinal image,chest x-ray image,bottom saliency,roc area,computational visual attention model,medical image
Visual search,Computer vision,Pattern recognition,Gaze,Salience (neuroscience),Computer science,Top-down and bottom-up design,Visual attention,Ground truth,Artificial intelligence,Abnormality detection,Visual saliency
Conference
Citations 
PageRank 
References 
7
0.47
9
Authors
4
Name
Order
Citations
PageRank
Varun Jampani118419.44
Ujjwal280.83
Jayanthi Sivaswamy333432.28
Vivek Vaidya4103.15