imageFeatureTCGA

library(imageFeatureTCGA)
library(HistoImagePlot)
library(dplyr)
library(SpatialExperiment)
library(ggplot2)

Installation

if (!requireNamespace("BiocManager", quietly = TRUE))
    install.packages("BiocManager")

BiocManager::install("waldronlab/HistoImagePlot")

Introduction

HoverNet is a deep learning model for simultaneous segmentation and classification of nuclei in multi-tissue histology images. This vignette demonstrates how to import HoverNet output files into Bioconductor’s spatial data structures and create visualizations of the segmentation results.

The package supports two main file formats:

Importing HoverNet JSON Data

From Local Files

Import the H5ad file into a SpatialExperiment

object from URLs (with Automatic Caching) The file will be automatically cached using BiocFileCache:

hov_file <- paste0(
    "https://store.cancerdatasci.org/hovernet/h5ad/",
    "TCGA-23-1021-01Z-00-DX1.F07C221B-D401-47A5-9519-10DE59CA1E9D.h5ad.gz")

thumb_path <- paste0(
    "https://store.cancerdatasci.org/hovernet/thumb/",
    "TCGA-23-1021-01Z-00-DX1.F07C221B-D401-47A5-9519-10DE59CA1E9D.png")

hn_spe <- HoverNet(hov_file, outClass = "SpatialExperiment") |>
    import()

The package provides a convenient function to overlay the segmentation on the original tissue thumbnail image.

Basic Overlay


thumb_path <- paste0(
    "https://store.cancerdatasci.org/hovernet/thumb/",
    "TCGA-23-1021-01Z-00-DX1.F07C221B-D401-47A5-9519-10DE59CA1E9D.png")

plotHoverNetH5ADOverlay(hn_spe, thumb_path)

Customized Overlay

plotHoverNetH5ADOverlay(
    hn_spe,
    thumb_path,
    title = "Ovarian Cancer Tissue - Cell Segmentation",
    point_size = 0.02,
    legend_point_size = 3
)

Custom Color Palette

custom_colors <- c(
    "no label" = "#808080",
    "neoplastic" = "#E31A1C",
    "inflammatory" = "#1F78B4",
    "stromal" = "#33A02C",
    "necrotic" = "#FF7F00",
    "benign epithelial" = "#6A3D9A"
)

plotHoverNetH5ADOverlay(
    hn_spe,
    thumb_path,
    color_palette = custom_colors,
    title = "Custom Color Scheme"
)

H5AD files contain additional computed features like mean intensity and nearest neighbor distance.

Visualizing Additional Features

h5ad_coords <- data.frame(spatialCoords(hn_spe), colData(hn_spe))

p1 <- ggplot(h5ad_coords, aes(x = x_centroid, y = y_centroid, 
                            color = mean_intensity)) +
    geom_point(size = 0.5) +
    scale_color_viridis_c() +
    coord_fixed() +
    theme_minimal() +
    labs(title = "Mean Intensity", color = "Intensity")

p2 <- ggplot(h5ad_coords, aes(x = x_centroid, y = y_centroid, 
                                color = nearest_neighbor_distance)) +
    geom_point(size = 0.5) +
    scale_color_viridis_c(option = "plasma") +
    coord_fixed() +
    theme_minimal() +
    labs(title = "Nearest Neighbor Distance", color = "Distance")

cowplot::plot_grid(p1, p2, ncol = 2)

Session Info

Click here for Session Info

sessionInfo()
#> R Under development (unstable) (2025-10-28 r88973)
#> Platform: x86_64-pc-linux-gnu
#> Running under: Ubuntu 24.04.4 LTS
#> 
#> Matrix products: default
#> BLAS/LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/libopenblasp-r0.3.26.so;  LAPACK version 3.12.0
#> 
#> locale:
#>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
#>  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8    LC_PAPER=en_US.UTF-8       LC_NAME=C                 
#>  [9] LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
#> 
#> time zone: America/New_York
#> tzcode source: system (glibc)
#> 
#> attached base packages:
#> [1] stats4    stats     graphics  grDevices utils     datasets  methods   base     
#> 
#> other attached packages:
#>  [1] ggplot2_4.0.1               SpatialExperiment_1.21.0    SingleCellExperiment_1.33.0 SummarizedExperiment_1.41.0
#>  [5] Biobase_2.71.0              GenomicRanges_1.63.1        Seqinfo_1.1.0               IRanges_2.45.0             
#>  [9] S4Vectors_0.49.0            BiocGenerics_0.57.0         generics_0.1.4              MatrixGenerics_1.23.0      
#> [13] matrixStats_1.5.0           dplyr_1.1.4                 HistoImagePlot_0.99.7       imageFeatureTCGA_0.99.56   
#> [17] colorout_1.3-2             
#> 
#> loaded via a namespace (and not attached):
#>  [1] DBI_1.2.3            httr2_1.2.2          remotes_2.5.0        anndataR_1.1.0       rlang_1.1.6          magrittr_2.0.4      
#>  [7] otel_0.2.0           compiler_4.6.0       RSQLite_2.4.5        png_0.1-8            vctrs_0.6.5          pkgconfig_2.0.3     
#> [13] fastmap_1.2.0        dbplyr_2.5.1         magick_2.9.0         XVector_0.51.0       ellipsis_0.3.2       labeling_0.4.3      
#> [19] rmarkdown_2.30       sessioninfo_1.2.3    tzdb_0.5.0           purrr_1.2.0          bit_4.6.0            xfun_0.56           
#> [25] gert_2.3.1           cachem_1.1.0         jsonlite_2.0.0       blob_1.2.4           rhdf5filters_1.23.3  DelayedArray_0.37.0 
#> [31] Rhdf5lib_1.33.0      R6_2.6.1             RColorBrewer_1.1-3   reticulate_1.44.1    pkgload_1.4.1        Rcpp_1.1.1          
#> [37] knitr_1.51           usethis_3.2.1        readr_2.1.6          BiocBaseUtils_1.13.0 Matrix_1.7-4         tidyselect_1.2.1    
#> [43] rstudioapi_0.18.0    dichromat_2.0-0.1    abind_1.4-8          yaml_2.3.12          codetools_0.2-20     curl_7.0.0          
#> [49] rjsoncons_1.3.2      pkgbuild_1.4.8       lattice_0.22-7       tibble_3.3.0         withr_3.0.2          S7_0.2.1            
#> [55] askpass_1.2.1        evaluate_1.0.5       BiocAddins_0.99.26   desc_1.4.3           BiocFileCache_3.1.0  pillar_1.11.1       
#> [61] BiocManager_1.30.27  filelock_1.0.3       rsconnect_1.7.0      rprojroot_2.1.1      credentials_2.0.3    hms_1.1.4           
#> [67] scales_1.4.0         glue_1.8.0           tools_4.6.0          BiocIO_1.21.0        sys_3.4.3            fs_1.6.6            
#> [73] cowplot_1.2.0        rhdf5_2.55.12        grid_4.6.0           devtools_2.4.6       TENxIO_1.13.3        cli_3.6.5           
#> [79] rappdirs_0.3.4       S4Arrays_1.11.1      viridisLite_0.4.2    gtable_0.3.6         digest_0.6.39        SparseArray_1.11.10 
#> [85] rjson_0.2.23         farver_2.1.2         memoise_2.0.1        htmltools_0.5.9      lifecycle_1.0.4      openssl_2.3.4       
#> [91] bit64_4.6.0-1