# iRfcb Introduction

## Introduction

The `iRfcb` package is an open-source R package designed to streamline the analysis of Imaging FlowCytobot (IFCB) data, with a focus on supporting marine ecological research and monitoring. By integrating R and Python functionalities, the package facilitates efficient handling and sharing of IFCB image data, extraction of key metadata, and preparation of outputs for further taxonomic, ecological, or spatial analyses.

This tutorial serves as an introduction to the core functionalities of `iRfcb`, providing step-by-step instructions for data preprocessing, taxonomic analysis, and SHARK-compliant data export. For additional guides—such as quality control of IFCB data, data sharing, and integration with MATLAB—please refer to the other tutorials available on the project’s webpage.

## Getting Started

### Installation

You can install the package from CRAN using:

    install.packages("iRfcb")

Load the `iRfcb` and `dplyr` libraries:

    library(iRfcb)

### Download Sample Data

To get started, download sample data from the SMHI IFCB Plankton Image Reference Library (Torstensson et al. 2024) with the following function:

    # Define data directory
    data_dir <- "data"

    # Download and extract test data in the data folder
    ifcb_download_test_data(dest_dir = data_dir)

## Extract IFCB Data

This section demonstrates a selection of general data extraction tools available in `iRfcb`.

### Extract Timestamps from IFCB Sample Filenames

Extract timestamps from sample names or filenames:

    # Example sample names
    filenames <- list.files("data/data/2023/D20230314", recursive = TRUE)

    # Print filenames
    print(filenames)

    ## [1] "D20230314T001205_IFCB134.adc" "D20230314T001205_IFCB134.hdr"
    ## [3] "D20230314T001205_IFCB134.roi" "D20230314T003836_IFCB134.adc"
    ## [5] "D20230314T003836_IFCB134.hdr" "D20230314T003836_IFCB134.roi"

    # Convert filenames to timestamps
    timestamps <- ifcb_convert_filenames(filenames)

    # Print result
    print(timestamps)

    ## # A tibble: 6 × 8
    ##   sample     timestamp           date        year month   day time   ifcb_number
    ##   <chr>      <dttm>              <date>     <dbl> <dbl> <int> <time> <chr>
    ## 1 D20230314… 2023-03-14 00:12:05 2023-03-14  2023     3    14 12'05" IFCB134
    ## 2 D20230314… 2023-03-14 00:12:05 2023-03-14  2023     3    14 12'05" IFCB134
    ## 3 D20230314… 2023-03-14 00:12:05 2023-03-14  2023     3    14 12'05" IFCB134
    ## 4 D20230314… 2023-03-14 00:38:36 2023-03-14  2023     3    14 38'36" IFCB134
    ## 5 D20230314… 2023-03-14 00:38:36 2023-03-14  2023     3    14 38'36" IFCB134
    ## 6 D20230314… 2023-03-14 00:38:36 2023-03-14  2023     3    14 38'36" IFCB134

If the filename includes ROI numbers (e.g., in an extracted `.png` image), a separate column, `roi`, will be added to the output.

    # Example sample names
    filenames <- list.files("data/png/Alexandrium_pseudogonyaulax_050")

    # Print filenames
    print(filenames)

    ## [1] "D20220712T210855_IFCB134_00042.png" "D20220712T210855_IFCB134_00164.png"
    ## [3] "D20220712T222710_IFCB134_00044.png"

    # Convert filenames to timestamps
    timestamps <- ifcb_convert_filenames(filenames)

    # Print result
    print(timestamps)

    ## # A tibble: 3 × 9
    ##   sample   timestamp           date        year month   day time     ifcb_number
    ##   <chr>    <dttm>              <date>     <dbl> <dbl> <int> <time>   <chr>
    ## 1 D202207… 2022-07-12 21:08:55 2022-07-12  2022     7    12 21:08:55 IFCB134
    ## 2 D202207… 2022-07-12 21:08:55 2022-07-12  2022     7    12 21:08:55 IFCB134
    ## 3 D202207… 2022-07-12 22:27:10 2022-07-12  2022     7    12 22:27:10 IFCB134
    ## # ℹ 1 more variable: roi <int>

### Calculate Volume Analyzed in ml

The analyzed volume of a sample can be calculated using data from `.hdr` and `.adc` files.

    # Path to HDR file
    hdr_file <- "data/data/2023/D20230314/D20230314T001205_IFCB134.hdr"

    # Calculate volume analyzed (in ml)
    volume_analyzed <- ifcb_volume_analyzed(hdr_file)

    # Print result
    print(volume_analyzed)

    ## [1] 4.568676

### Get Sample Runtime

Get the runtime from a `.hdr` file:

    # Get runtime from HDR-file
    run_time <- ifcb_get_runtime(hdr_file)

    # Print result
    print(run_time)

    ## $runtime
    ## [1] 1200.853
    ##
    ## $inhibittime
    ## [1] 104.3704

### Read Feature Data

Read all feature files (`.csv`) from a folder:

    # Read feature files from a folder
    features <- ifcb_read_features("data/features/2023/",
                                   verbose = FALSE) # Do not print progress bar

    # Print output from the first sample in the list
    print(features[[1]])

    ## # A tibble: 1,218 × 237
    ##    roi_number  Area Biovolume BoundingBox_xwidth BoundingBox_ywidth ConvexArea
    ##         <dbl> <dbl>     <dbl>              <dbl>              <dbl>      <dbl>
    ##  1          2   446     6083.                 31                 21        542
    ##  2          3  4326   142783.                111                 63       5186
    ##  3          4  9739   336908.                202                129      10581
    ##  4          5   580     9187.                 27                 28        602
    ##  5          6  3927   120367.                 99                 50       4191
    ##  6          7   290     3112.                 22                 20        335
    ##  7          8  4437   183891.                 90                 62       4894
    ##  8          9   576     9297.                 27                 29        605
    ##  9         10   540     7712.                 28                 25        564
    ## 10         11   990    18779.                 53                 31       1197
    ## # ℹ 1,208 more rows
    ## # ℹ 231 more variables: ConvexPerimeter <dbl>, Eccentricity <dbl>,
    ## #   EquivDiameter <dbl>, Extent <dbl>, FeretDiameter <dbl>, H180 <dbl>,
    ## #   H90 <dbl>, Hflip <dbl>, MajorAxisLength <dbl>, MinorAxisLength <dbl>,
    ## #   Orientation <dbl>, Perimeter <dbl>, RWcenter2total_powerratio <dbl>,
    ## #   RWhalfpowerintegral <dbl>, Solidity <dbl>, moment_invariant1 <dbl>,
    ## #   moment_invariant2 <dbl>, moment_invariant3 <dbl>, …

    # Read only multiblob feature files
    multiblob_features <- ifcb_read_features("data/features/2023",
                                             multiblob = TRUE,
                                             verbose = FALSE)

    # Print output from the first sample in the list
    print(multiblob_features[[1]])

    ## # A tibble: 26 × 22
    ##    roi_number blob_number  Area MajorAxisLength MinorAxisLength Eccentricity
    ##         <dbl>       <dbl> <dbl>           <dbl>           <dbl>        <dbl>
    ##  1        154           1  3647           110.             45.0        0.912
    ##  2        154           2  1626            77.5            30.7        0.918
    ##  3        214           1  7456           232.            123.         0.849
    ##  4        214           2  4840           102.             68.3        0.741
    ##  5        214           3   910            54.2            28.5        0.850
    ##  6        214           4   153            19.0            10.9        0.817
    ##  7        447           1 29964           808.             64.7        0.997
    ##  8        447           2   668            77.4            34.3        0.896
    ##  9        537           1  2989            65.1            59.1        0.419
    ## 10        537           2  2978            63.5            60.1        0.323
    ## # ℹ 16 more rows
    ## # ℹ 16 more variables: Orientation <dbl>, ConvexArea <dbl>,
    ## #   EquivDiameter <dbl>, Solidity <dbl>, Extent <dbl>, Perimeter <dbl>,
    ## #   ConvexPerimeter <dbl>, FeretDiameter <dbl>, BoundingBox_xwidth <dbl>,
    ## #   BoundingBox_ywidth <dbl>, shapehist_mean_normEqD <dbl>,
    ## #   shapehist_mode_normEqD <dbl>, shapehist_median_normEqD <dbl>,
    ## #   shapehist_skewness_normEqD <dbl>, shapehist_kurtosis_normEqD <dbl>, …

## Extract Images from ROI files

IFCB images stored in `.roi` files can be extracted as `.png` files using the `iRfcb` package, as demonstrated below.

Extract all images from a sample using the `ifcb_extract_pngs()` function. You can specify the `out_folder`, but by default, images will be saved in a subdirectory within the same directory as the ROI file. The `gamma` can be adjusted to enhance image contrast, and an optional scale bar can be added by specifying `scale_bar_um`.

    # All ROIs in sample
    ifcb_extract_pngs(
      "data/data/2023/D20230314/D20230314T001205_IFCB134.roi",
      gamma = 1, # Default gamma value
      scale_bar_um = 5 # Add a 5 micrometer scale bar
    )

    ## Writing 1218 ROIs from D20230314T001205_IFCB134.roi to data/data/2023/D20230314/D20230314T001205_IFCB134

Extract specific ROIs:

    # Only ROI number 2 and 5
    ifcb_extract_pngs("data/data/2023/D20230314/D20230314T003836_IFCB134.roi",
                      ROInumbers = c(2, 5))

    ## Writing 2 ROIs from D20230314T003836_IFCB134.roi to data/data/2023/D20230314/D20230314T003836_IFCB134

To extract annotated images or classified results from MATLAB files, please see the `vignette("image-export-tutorial")` and `vignette("matlab-tutorial")` tutorials.

## Classify IFCB Images

IFCB images can be classified directly in R using a CNN model served by a Gradio application. By default, the classification functions use a public example Space hosted on Hugging Face (`https://irfcb-classify.hf.space`). This Space has limited resources and is intended for testing and demonstration purposes. For large-scale or production classification, we recommend deploying your own instance of the IFCB Classification App with your own model and passing its URL via the `gradio_url` argument.

### Available Models

Use `ifcb_classify_models()` to list the CNN models available on the Gradio server:

    ifcb_classify_models()

### Classify All Images in a Sample

`ifcb_classify_sample()` extracts images from a `.roi` file internally and returns predictions without requiring a separate extraction step:

    # Classify all images in a sample
    results <- ifcb_classify_sample(
      "data/data/2023/D20230314/D20230314T001205_IFCB134.roi",
      verbose = FALSE
    )

    # Print result
    print(results)

### Classify Pre-extracted PNG Images

If images have already been extracted, pass a vector of PNG file paths to `ifcb_classify_images()`:

    # List extracted PNG files
    png_files <- list.files(
      "data/data/2023/D20230314/D20230314T001205_IFCB134",
      pattern = "\\.png$",
      full.names = TRUE
    )

    # Classify images
    results <- ifcb_classify_images(png_files, verbose = FALSE)

    # Print result
    print(results)

Both functions return a data frame with `file_name`, `class_name`, `class_name_auto`, `score`, and `model_name` columns, and query the Gradio API at `https://irfcb-classify.hf.space` by default. Per-class F2 optimal thresholds are always applied: `class_name` contains the threshold-applied classification (labeled `"unclassified"` when below threshold), while `class_name_auto` contains the winning class without any threshold. The `top_n` argument controls how many top predictions are returned per image, and `model_name` specifies which CNN model to use (default: `"SMHI NIVA ResNet50 V5"`).

### Save Classification Results

`ifcb_save_classification()` classifies all images in a `.roi` file and saves the full score matrix. Three output formats are supported via the `format` argument:

    # HDF5 (default) - IFCB Dashboard v3 format (requires hdf5r package)
    ifcb_save_classification(
      "data/data/2023/D20230314/D20230314T001205_IFCB134.roi",
      output_folder = "output"
    )
    # Creates: output/D20230314T001205_IFCB134_class.h5

    # MAT - IFCB Dashboard v1 format (requires Python with scipy)
    ifcb_save_classification(
      "data/data/2023/D20230314/D20230314T001205_IFCB134.roi",
      output_folder = "output",
      format = "mat"
    )
    # Creates: output/D20230314T001205_IFCB134_class_v1.mat

    # CSV - ClassiPyR-compatible format
    ifcb_save_classification(
      "data/data/2023/D20230314/D20230314T001205_IFCB134.roi",
      output_folder = "output",
      format = "csv"
    )
    # Creates: output/D20230314T001205_IFCB134.csv

The output file contains `output_scores` (N x C matrix), `class_labels`, `roi_numbers`, per-class `thresholds`, and `class_labels_above_threshold`.

## Taxonomical Data

Maintaining up-to-date taxonomic data is essential for ensuring accurate species names and classifications, which directly impact calculations like carbon concentrations in `iRfcb`.

Up-to-date taxonomy also ensures data harmonization by preventing issues like misspellings, outdated synonyms, or inconsistent classifications. This consistency is crucial for integrating and comparing datasets across studies, regions, and time periods, improving the reliability of scientific outcomes.

### Taxon matching with WoRMS

Taxonomic names can be matched against the World Register of Marine Species (WoRMS), ensuring accuracy and consistency. The `iRfcb` package includes a built-in function for taxon matching via the WoRMS API, featuring a retry mechanism to handle server errors, making it particularly useful for automated data pipelines. For additional tools and functionality, the R package `worrms` provides a comprehensive suite of options for interacting with the WoRMS database.

    # Example taxa names
    taxa_names <- c("Alexandrium_pseudogonyaulax", "Guinardia_delicatula")

    # Retrieve WoRMS records
    worms_records <- ifcb_match_taxa_names(taxa_names,
                                           verbose = FALSE) # Do not print progress bar

    # Print result
    print(worms_records)

    ## # A tibble: 2 × 29
    ##   name  AphiaID url   scientificname authority status unacceptreason taxonRankID
    ##   <chr>   <int> <chr> <chr>          <chr>     <chr>  <lgl>                <int>
    ## 1 Alex…  109713 http… Alexandrium p… (Biechel… accep… NA                     220
    ## 2 Guin…  149112 http… Guinardia del… (Cleve) … unass… NA                     220
    ## # ℹ 21 more variables: rank <chr>, valid_AphiaID <int>, valid_name <chr>,
    ## #   valid_authority <chr>, parentNameUsageID <int>, originalNameUsageID <int>,
    ## #   kingdom <chr>, phylum <chr>, class <chr>, order <chr>, family <chr>,
    ## #   genus <chr>, citation <chr>, lsid <chr>, isMarine <int>, isBrackish <lgl>,
    ## #   isFreshwater <int>, isTerrestrial <int>, isExtinct <int>, match_type <chr>,
    ## #   modified <chr>

### Check whether a class name is a diatom

This function takes a list of taxa names, cleans them, retrieves their corresponding classification records from WoRMS, and checks if they belong to the specified diatom class. The function only uses the first name (genus name) of each taxa for classification. This function can be useful for converting biovolumes to carbon according to Menden-Deuer and Lessard (2000). See `vol2C_nondiatom()` and `vol2C_lgdiatom()` for carbon calculations (not included in NAMESPACE).

    # Read class2use file and select five taxa
    class2use <- ifcb_get_mat_variable("data/config/class2use.mat")[10:15]

    # Create a dataframe with class name and result from `ifcb_is_diatom`
    class_list <- data.frame(class2use,
                             is_diatom = ifcb_is_diatom(class2use, verbose = FALSE))

    # Print rows 10-15 of result
    print(class_list)

    ##                    class2use is_diatom
    ## 1        Nodularia_spumigena     FALSE
    ## 2            Cryptomonadales     FALSE
    ## 3    Acanthoica_quattrospina     FALSE
    ## 4 Asterionellopsis_glacialis      TRUE
    ## 5                  Centrales      TRUE
    ## 6            Centrales_chain      TRUE

The default class for diatoms is defined as Bacillariophyceae, but may be adjusted using the `diatom_class` argument.

### Find trophic type of plankton taxa

This function takes a list of taxa names and matches them with the SMHI Trophic Type list used in SHARK.

    # Example taxa names
    taxa_list <- c(
      "Acanthoceras zachariasii",
      "Nodularia spumigena",
      "Acanthoica quattrospina",
      "Noctiluca",
      "Gymnodiniales"
    )

    # Get trophic type for taxa
    trophic_type <- ifcb_get_trophic_type(taxa_list)

    # Print result
    print(trophic_type)

    ## [1] "AU" "AU" "MX" "HT" "NS"

## SHARK export

This function is used by SMHI to map IFCB data into the SHARK standard data delivery format. An example submission is also provided in `iRfcb`.

    # Get column names from example
    shark_colnames <- ifcb_get_shark_colnames()

    # Print column names
    print(shark_colnames)

    ## # A tibble: 0 × 67
    ## # ℹ 67 variables: MYEAR <dbl>, STATN <chr>, SAMPLING_PLATFORM <chr>,
    ## #   PROJ <chr>, ORDERER <chr>, SHIPC <chr>, CRUISE_NO <dbl>, DATE_TIME <dbl>,
    ## #   SDATE <date>, STIME <time>, TIMEZONE <chr>, LATIT <dbl>, LONGI <dbl>,
    ## #   POSYS <chr>, WADEP <lgl>, MPROG <chr>, MNDEP <dbl>, MXDEP <dbl>,
    ## #   SLABO <chr>, ACKR_SMP <chr>, SMTYP <chr>, PDMET <chr>, SMVOL <dbl>,
    ## #   METFP <chr>, IFCBNO <chr>, SMPNO <chr>, LATNM <chr>, SFLAG <chr>,
    ## #   LATNM_SFLAG <chr>, TRPHY <chr>, APHIA_ID <dbl>, IMAGE_VERIFICATION <chr>, …

    # Load example stored from `iRfcb`
    shark_example <- ifcb_get_shark_example()

    # Print the SHARK data submission example
    print(shark_example)

    ## # A tibble: 5 × 67
    ##   MYEAR STATN          SAMPLING_PLATFORM PROJ  ORDERER SHIPC CRUISE_NO DATE_TIME
    ##   <dbl> <chr>          <chr>             <chr> <chr>   <chr>     <dbl> <chr>
    ## 1  2022 RV_FB_D202207… IFCB              IFCB… SMHI    77SE         12 2.02e+15
    ## 2  2022 RV_FB_D202207… IFCB              IFCB… SMHI    77SE         12 2.02e+15
    ## 3  2022 RV_FB_D202207… IFCB              IFCB… SMHI    77SE         12 2.02e+15
    ## 4  2022 RV_FB_D202207… IFCB              IFCB… SMHI    77SE         12 2.02e+15
    ## 5  2022 RV_FB_D202207… SveaFB            IFCB… SMHI    77SE         12 2.02e+15
    ## # ℹ 59 more variables: SDATE <date>, STIME <time>, TIMEZONE <chr>, LATIT <dbl>,
    ## #   LONGI <dbl>, POSYS <chr>, WADEP <lgl>, MPROG <chr>, MNDEP <dbl>,
    ## #   MXDEP <dbl>, SLABO <chr>, ACKR_SMP <chr>, SMTYP <chr>, PDMET <chr>,
    ## #   SMVOL <dbl>, METFP <chr>, IFCBNO <chr>, SMPNO <chr>, LATNM <chr>,
    ## #   SFLAG <chr>, LATNM_SFLAG <chr>, TRPHY <chr>, APHIA_ID <dbl>,
    ## #   IMAGE_VERIFICATION <chr>, VERIFIED_BY <lgl>, COUNT <dbl>, ABUND <dbl>,
    ## #   BIOVOL <dbl>, C_CONC <dbl>, QFLAG <lgl>, COEFF <dbl>, CLASS_NAME <chr>, …

This concludes this tutorial for the `iRfcb` package. For additional guides—such as quality control of IFCB data, data sharing, and integration with MATLAB—please refer to the other tutorials available on the project’s webpage. See how data pipelines can be constructed using `iRfcb` in the following Example Project. Happy analyzing!

## Citation

    ## To cite package 'iRfcb' in publications use:
    ##
    ##   Anders Torstensson (2026). iRfcb: Tools for Managing Imaging
    ##   FlowCytobot (IFCB) Data. R package version 0.8.1.
    ##   https://CRAN.R-project.org/package=iRfcb
    ##
    ## A BibTeX entry for LaTeX users is
    ##
    ##   @Manual{,
    ##     title = {iRfcb: Tools for Managing Imaging FlowCytobot (IFCB) Data},
    ##     author = {Anders Torstensson},
    ##     year = {2026},
    ##     note = {R package version 0.8.1},
    ##     url = {https://CRAN.R-project.org/package=iRfcb},
    ##   }

## References

- Torstensson, A., Skjevik, A-T., Mohlin, M., Karlberg, M. and Karlson, B. (2024). SMHI IFCB Plankton Image Reference Library. SciLifeLab. Dataset. https://doi.org/10.17044/scilifelab.25883455.v3