--- title: "grayleafspotr Workflow" output: BiocStyle::html_document: toc: true toc_depth: 3 vignette: > %\VignetteIndexEntry{grayleafspotr Workflow} %\VignetteEngine{knitr::rmarkdown} %\VignetteEncoding{UTF-8} --- ```{r setup, include=FALSE} knitr::opts_chunk$set( echo = TRUE, message = FALSE, warning = FALSE, fig.width = 7, fig.height = 4.5 ) library(grayleafspotr) # Gate the pipeline chunks with a presence check. If an external basilisk # cache is configured, it must exist before the live examples can run. Live # Python examples are not run on Bioconductor build machines. is_bioc_build <- identical(Sys.getenv("IS_BIOC_BUILD_MACHINE"), "true") basilisk_dir <- Sys.getenv("BASILISK_EXTERNAL_DIR", unset = "") py_ok <- !is_bioc_build && (!nzchar(basilisk_dir) || dir.exists(basilisk_dir)) && tryCatch( grayleafspot_python_available(engine_model = "localunet"), error = function(e) FALSE ) ``` ## Abstract {-} Gray leaf spot (GLS) is a fungal disease caused by the ascomycete *Magnaporthe oryzae*, an economically important pathogen best known as the causal agent of rice blast and also associated with gray leaf spot on other grass hosts. In laboratory settings, fungal isolates are grown on petri dishes and photographed at successive time points to characterise colony expansion, morphology, and structural organisation. Manual measurement of these traits is time-consuming and operator-dependent. `grayleafspotr` provides a fully automated pipeline for quantitative phenotyping of GLS colonies from time-lapse plate photographs. The package uses a bundled SmallUNet deep-learning segmentation model to identify colonies in each image, then extracts morphometric and texture features that describe colony growth, shape, and internal organisation over time. The resulting tidy data frame can be explored with included template `ggplot2` visualisations or passed to any downstream R analysis. Python dependencies are managed automatically through `basilisk`; no manual Python environment setup is required. ### Interoperability with Bioconductor {-} `grayleafspotr` integrates with the Bioconductor ecosystem in two ways. Python environment management uses `basilisk`, so the segmentation model runs in a versioned, reproducible environment rather than depending on the user's system Python. For visual quality control, `plot_grayleafspot_overlay()` uses `EBImage` to draw the detected dish boundary, colony outline, and crack segments directly on the source photograph, so the numeric summary features in `$results` can be checked against the underlying image rather than trusted as an opaque black box. General-purpose plate-image segmentation tools (e.g. ImageJ/Fiji macros, or ad hoc OpenCV scripts) typically require users to re-implement this kind of feature extraction and visual-QC step themselves; `grayleafspotr` packages the full path from raw photograph to tidy, `ggplot2`-ready results and an `EBImage`-based visual audit trail in one reproducible pipeline. --- ## Package overview ### What the package does Given a folder of plate photographs, `grayleafspotr`: 1. **Detects the petri dish** boundary using classical circle fitting. 2. **Segments the colony** inside the dish with a SmallUNet model (`best_area_w_0.7.pt`). 3. **Extracts per-image features**: area (mm²), equivalent diameter, circularity, eccentricity, edge roughness, crack coverage, texture entropy, and a radial intensity profile. 4. **Returns a tidy result** object (`grayleafspot_run`) containing a data frame indexed by filename and imaging day. 5. **Provides template plots**, one function per figure, all returning `ggplot2` objects ready for further customisation. 6. **Supports visual QC**: `plot_grayleafspot_overlay()` draws the detected ROIs on the source image via `EBImage`. ### Input requirements | Requirement | Detail | |---|---| | Image formats | JPEG, PNG, BMP, TIFF, WEBP | | Naming convention | Encode the day with a `d\d+` token: `*_d04_*.jpg` for day 4 | | Plate diameter | Standard 90 mm (adjustable via `plate_diameter_mm`) | | Folder structure | One folder per experiment; one image per plate per time point | Example filenames and the day values they produce: ``` 20260210_P001_06-FEB_WT_PCBM_SUB_d04_TOP.jpg → day 4 20260212_P001_06-FEB_WT_PCBM_SUB_d06_TOP.jpg → day 6 20260216_P001_06-FEB_WT_PCBM_SUB_d10_TOP.jpg → day 10 ``` ### Workflow at a glance ``` Plate images (folder) │ ▼ grayleafspot_analyze() / grayleafspot_run() │ ├─ Dish geometry detection (classical Hough transform) ├─ SmallUNet segmentation (best_area_w_0.7.pt) └─ Feature extraction (area, shape, texture, cracks, radial) │ ▼ grayleafspot_run S3 object │ ├─ $results per-image feature data frame └─ $run run manifest (paths, timestamp, engine) │ ▼ Template ggplot2 plots / EBImage ROI overlay / tidy data / custom analysis ``` --- ## Installation Install from Bioconductor: ```r if (!requireNamespace("BiocManager", quietly = TRUE)) install.packages("BiocManager") BiocManager::install("grayleafspotr") ``` `basilisk` installs Python dependencies when you first run the analysis pipeline. For setup details and manual configuration, see [Developer note: Python override](#developer-note-python-override). --- ## Bundled example data The package ships three pre-computed example results so that all plotting and data-wrangling functions can be explored without running the full pipeline. ### Load the example run ```{r load-example-run} example_run <- example_grayleafspot_results() ``` ### Inspect the feature table ```{r inspect-feature-table} example_run$results[, c("filename", "day", "area_mm2", "diameter_mm", "circularity", "crack_coverage_pct", "qc_status")] ``` ### Locate bundled source images The three plate photographs used to generate this example are also included in the package and are accessible via `system.file()`: ```{r locate-bundled-images} image_dir <- system.file("extdata", "testdata", "06FEB", package = "grayleafspotr") list.files(image_dir) ``` --- ## Template visualisations Every plotting function accepts a `grayleafspot_run` object and returns a `ggplot2` object that can be customised with standard `ggplot2` calls. ### Colony expansion over time Colony equivalent diameter (mm) plotted against imaging day. ```{r plot-colony-expansion} plot_colony_expansion(example_run) ``` ### Growth rate and edge roughness Daily growth increment (mm/day) alongside a measure of colony edge irregularity. ```{r plot-growth-roughness} plot_growth_roughness(example_run) ``` ### Crack coverage and count Proportion of the colony mask classified as cracked tissue, alongside the total crack count, a proxy for structural stress. ```{r plot-stress-remodeling} plot_stress_remodeling(example_run) ``` ### Texture organisation Texture entropy and the centre-to-edge entropy gradient reflect internal colony heterogeneity. ```{r plot-texture-organization} plot_texture_organization(example_run) ``` ### Shape versus stress Eccentricity (0 = circular, 1 = elongated) plotted against crack coverage to reveal coupling between morphology and structural remodelling. ```{r plot-shape-vs-stress} plot_shape_vs_stress(example_run) ``` ### Feature correlation heatmap Pearson correlations between all numeric features. ```{r plot-feature-heatmap} plot_feature_heatmap(example_run) ``` ### Radial intensity profile Mean pixel intensity as a function of normalised radial distance from the colony centre. ```{r plot-radial-profile} plot_radial_profile(example_run) ``` --- ## Work with tidy data Convert the run object to a plain data frame for any downstream workflow: ```{r growth-data-tidy} growth_data <- as_grayleafspot_growth_data(example_run) growth_data ``` ### Custom plot Because every template function returns a `ggplot2` object, you can layer on additional components: ```{r custom-plot} plot_colony_expansion(example_run) + ggplot2::labs( title = "Colony expansion: 06-FEB experiment", subtitle = "WT strain, PCBM substrate" ) + ggplot2::theme_classic() ``` --- ## Analyze your own images ### Prepare your image folder Place all plate photographs for one experiment in a single directory. The filename must contain a `d\d+` token that encodes the imaging day: ``` my_experiment/ ├── isolate_A_d03_rep1.jpg ├── isolate_A_d05_rep1.jpg ├── isolate_A_d07_rep1.jpg └── ... ``` The examples below use the three bundled 06FEB test images (`inst/extdata/testdata/06FEB/`) in place of `my_experiment/`. When the Python availability check returns `FALSE`, the vignette shows the code without running these chunks. ### Run the analysis: simple entry point `grayleafspot_run()` is the recommended entry point for most users. It returns the raw JSON payload as a named list. ```{r run-simple-entry-point, eval=py_ok} img_dir <- system.file("extdata", "testdata", "06FEB", package = "grayleafspotr") out_dir <- file.path(tempdir(), "grayleafspotr-workflow-demo") res <- grayleafspot_run( input_dir = img_dir, output_dir = out_dir, run_name = "isolate_A" ) res$results # per-image feature table (data frame) res$run # run manifest ``` ### Full-featured alternative: `grayleafspot_analyze()` `grayleafspot_analyze()` returns a `grayleafspot_run` S3 object with direct access to the template plots: ```{r run-full-featured, eval=py_ok} run <- grayleafspot_analyze( input_dir = img_dir, output_dir = out_dir, run_name = "isolate_A_analyze", verbose = FALSE ) plot_colony_expansion(run) ``` ### Visual QC: overlay detected ROIs on the source image `plot_grayleafspot_overlay()` draws the detected dish boundary (yellow), colony outline (red), and crack segments (cyan) on top of the original photograph, using `EBImage`. This directly answers "did the pipeline segment what I expect?" without having to trust the summary statistics alone: ```{r visualize-overlay, eval=py_ok} image_file <- list.files(img_dir, full.names = TRUE)[1] plot_grayleafspot_overlay(run, image_path = image_file) ``` ### Reload saved results Every run writes outputs to a timestamped sub-folder. Reload a previous run without re-running the pipeline: ```{r reload-saved-results, eval=py_ok} saved_dir <- run$run$output_dir reloaded <- read_grayleafspot_results(saved_dir) plot_colony_expansion(reloaded) ``` --- ## Developer note: Python override `basilisk` installs NumPy, OpenCV, PyTorch, scikit-image, and the other Python dependencies on the first pipeline call. Setup may take a few minutes; subsequent calls use the cached environment. If `basilisk` cannot create an environment on your system, you can set up one manually. This may be necessary on some Linux systems or HPC clusters. Follow the [manual Python environment setup instructions in the README](https://github.com/rotsl/grayleafspotr#manual-python-environment-setup). Create the environment outside the package directory so development tools do not have to scan its contents. To use an existing environment, set the path to its Python interpreter: ```r # ~/.Rprofile: optional Python override Sys.setenv(GRAYLEAFSPOTR_PYTHON = "/path/to/rvenv/bin/python") ``` When `GRAYLEAFSPOTR_PYTHON` is set, the pipeline uses that interpreter instead of the basilisk-managed environment. --- ## References {-} Related datasets and software, by the same author: * Rohan R (2026). *Time-series Magnaporthe colony images from twelve petri dishes and morphometric analysis results generated using metrics-petri 3.0.0*. BioStudies S-BSST3199. * Rohan R (2026). *metrics-petri* [software]. Harvard Dataverse. --- ## Session information {-} ```{r session-info} sessionInfo() ```