FIG 3.

(A) Higher magnification of the parallel coordinate plot bounded by the red box in Figure 2. The different y-axes correspond to different image metrics determined by HistoQC and may have their own ranges and scales. Each horizontally oriented line, in either gray or blue, represents a whole-slide image (WSI) analyzed by HistoQC. By examining the convergence or divergence of each horizontal WSI line with respect to the rest of the images in the cohort, batch effects and outliers can be more easily visually identified. In the example illustrated, the user has interactively drawn a gray box (red arrow) to select images with a grayscale intensity value between 0.4 and 0.5, resulting in all lines that do not meet this criterion turning gray. This image selection mechanism alters the visibility of slides in both the table (Fig 2 green arrow) and the thumbnails (Fig 2 blue arrow). Furthermore, the user can dynamically drag or extend the gray box upward and downward to update the visible slides in real time. As a result, images with (B) low and (C) high grayscale brightness values are easier to identify and review.