Title
Investigating And Exploiting Image Resolution For Transfer Learning-Based Skin Lesion Classification
Abstract
Skin cancer is among the most common cancer types. Dermoscopic image analysis improves the diagnostic accuracy for detection of malignant melanoma and other pigmented skin lesions when compared to unaided visual inspection. Hence, computer-based methods to support medical experts in the diagnostic procedure are of great interest. Fine-tuning pre-trained convolutional neural networks (CNNs) has been shown to work well for skin lesion classification. Pre-trained CNNs are typically trained with natural images of a fixed image size significantly smaller than captured skin lesion images and consequently dermoscopic images are downsampled for fine-tuning. However, useful medical information may be lost during this transformation.In this paper, we explore the effect of input image size on skin lesion classification performance of fine-tuned CNNs. For this, we resize dermoscopic images to different resolutions, ranging from 64 x 64 to 768 x 768 pixels and investigate the resulting classification performance of three well-established CNNs, namely DenseNet-121, ResNet-18, and ResNet-50. Our results show that using very small images (of size 64 x 64 pixels) degrades the classification performance, while images of size 128 x 128 pixels and above support good performance with larger image sizes leading to slightly improved classification.We further propose a novel fusion approach based on a three-level ensemble strategy that exploits multiple fine-tuned networks trained with dermoscopic images at various sizes. When applied on the ISIC 2017 skin lesion classification challenge, our fusion approach yields an area under the receiver operating characteristic curve of 89.2% and 96.6% for melanoma classification and seborrheic keratosis classification, respectively, outperforming state-of-the-art algorithms.
Year
DOI
Venue
2020
10.1109/ICPR48806.2021.9412307
2020 25TH INTERNATIONAL CONFERENCE ON PATTERN RECOGNITION (ICPR)
Keywords
DocType
ISSN
Dermatology, skin cancer, dermoscopy, medical image analysis, deep learning, image resolution, transfer learning
Conference
1051-4651
Citations 
PageRank 
References 
0
0.34
0
Authors
6
Name
Order
Citations
PageRank
Amirreza Mahbod1323.77
Gerald Schaefer2146.81
Chunliang Wang311.07
Rupert Ecker4294.05
G Dorffner5586.97
Isabella Ellinger6294.38