Journal of Pathology Informatics

RESEARCH ARTICLE
Year
: 2016  |  Volume : 7  |  Issue : 1  |  Page : 17-

Empirical comparison of color normalization methods for epithelial-stromal classification in H and E images


Amit Sethi1, Lingdao Sha2, Abhishek Ramnath Vahadane3, Ryan J Deaton4, Neeraj Kumar3, Virgilia Macias4, Peter H Gann4 
1 Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam; Department of Pathology, University of Illinois, Chicago, IL, India
2 Department of Electrical and Computer Engineering, University of Illinois, Chicago, IL, USA
3 Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
4 Department of Pathology, University of Illinois, Chicago, IL, USA

Correspondence Address:
Amit Sethi
Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam; Department of Pathology, University of Illinois, Chicago, IL
India

Context: Color normalization techniques for histology have not been empirically tested for their utility for computational pathology pipelines. Aims: We compared two contemporary techniques for achieving a common intermediate goal - epithelial-stromal classification. Settings and Design: Expert-annotated regions of epithelium and stroma were treated as ground truth for comparing classifiers on original and color-normalized images. Materials and Methods: Epithelial and stromal regions were annotated on thirty diverse-appearing H and E stained prostate cancer tissue microarray cores. Corresponding sets of thirty images each were generated using the two color normalization techniques. Color metrics were compared for original and color-normalized images. Separate epithelial-stromal classifiers were trained and compared on test images. Main analyses were conducted using a multiresolution segmentation (MRS) approach; comparative analyses using two other classification approaches (convolutional neural network [CNN], Wndchrm) were also performed. Statistical Analysis: For the main MRS method, which relied on classification of super-pixels, the number of variables used was reduced using backward elimination without compromising accuracy, and test - area under the curves (AUCs) were compared for original and normalized images. For CNN and Wndchrm, pixel classification test-AUCs were compared. Results: Khan method reduced color saturation while Vahadane reduced hue variance. Super-pixel-level test-AUC for MRS was 0.010-0.025 (95% confidence interval limits ± 0.004) higher for the two normalized image sets compared to the original in the 10-80 variable range. Improvement in pixel classification accuracy was also observed for CNN and Wndchrm for color-normalized images. Conclusions: Color normalization can give a small incremental benefit when a super-pixel-based classification method is used with features that perform implicit color normalization while the gain is higher for patch-based classification methods for classifying epithelium versus stroma.


How to cite this article:
Sethi A, Sha L, Vahadane AR, Deaton RJ, Kumar N, Macias V, Gann PH. Empirical comparison of color normalization methods for epithelial-stromal classification in H and E images.J Pathol Inform 2016;7:17-17


How to cite this URL:
Sethi A, Sha L, Vahadane AR, Deaton RJ, Kumar N, Macias V, Gann PH. Empirical comparison of color normalization methods for epithelial-stromal classification in H and E images. J Pathol Inform [serial online] 2016 [cited 2021 May 8 ];7:17-17
Available from: https://www.jpathinformatics.org/article.asp?issn=2153-3539;year=2016;volume=7;issue=1;spage=17;epage=17;aulast=Sethi;type=0