sits_reclassify: Reclassify a classified cube

In sits: Satellite Image Time Series Analysis for Earth Observation Data Cubes

Reclassify a classified cube

Description

Apply a set of named expressions to reclassify a classified image. The expressions should use character values to refer to labels in logical expressions.

Usage

sits_reclassify(cube, ...)

## S3 method for class 'class_cube'
sits_reclassify(
  cube,
  ...,
  mask,
  rules,
  memsize = 4L,
  multicores = 2L,
  output_dir,
  version = "v1",
  progress = TRUE
)

## Default S3 method:
sits_reclassify(cube, ...)

Arguments

cube	Image cube to be reclassified (class = "class_cube")
...	Other parameters for specific functions.
mask	Image cube with additional information to be used in expressions (class = "class_cube").
rules	Expressions to be evaluated (named list).
memsize	Memory available for classification in GB (integer, min = 1, max = 16384).
multicores	Number of cores to be used for classification (integer, min = 1, max = 2048).
output_dir	Directory where files will be saved (character vector of length 1 with valid location).
version	Version of resulting image (character).
progress	Set progress bar??

Value

An object of class "class_cube" (reclassified cube).

Note

Reclassification of a remote sensing map refers to changing the classes assigned to different pixels in the image. Reclassification involves assigning new classes to pixels based on additional information from a reference map. Users define rules according to the desired outcome. These rules are then applied to the classified map to produce a new map with updated classes.

sits_reclassify() allow any valid R expression to compute reclassification. User should refer to cube and mask to construct logical expressions. Users can use can use any R expression that evaluates to logical. TRUE values will be relabeled to expression name. Updates are done in asynchronous manner, that is, all expressions are evaluated using original classified values. Expressions are evaluated sequentially and resulting values are assigned to output cube. Last expressions has precedence over first ones.

Author(s)

Rolf Simoes, [e-mail]

Gilberto Camara, [e-mail]

Examples

if (sits_run_examples()) {
    # Open mask map
    data_dir <- system.file("extdata/raster/prodes", package = "sits")
    prodes2021 <- sits_cube(
        source = "USGS",
        collection = "LANDSAT-C2L2-SR",
        data_dir = data_dir,
        parse_info = c(
            "X1", "X2", "tile", "start_date", "end_date",
            "band", "version"
        ),
        bands = "class",
        version = "v20220606",
        labels = c(
            "1" = "Forest", "2" = "Water", "3" = "NonForest",
            "4" = "NonForest2", "6" = "d2007", "7" = "d2008",
            "8" = "d2009", "9" = "d2010", "10" = "d2011",
            "11" = "d2012", "12" = "d2013", "13" = "d2014",
            "14" = "d2015", "15" = "d2016", "16" = "d2017",
            "17" = "d2018", "18" = "r2010", "19" = "r2011",
            "20" = "r2012", "21" = "r2013", "22" = "r2014",
            "23" = "r2015", "24" = "r2016", "25" = "r2017",
            "26" = "r2018", "27" = "d2019", "28" = "r2019",
            "29" = "d2020", "31" = "r2020", "32" = "Clouds2021",
            "33" = "d2021", "34" = "r2021"
        ),
        progress = FALSE
    )
    #' Open classification map
    data_dir <- system.file("extdata/raster/classif", package = "sits")
    ro_class <- sits_cube(
        source = "MPC",
        collection = "SENTINEL-2-L2A",
        data_dir = data_dir,
        parse_info = c(
            "X1", "X2", "tile", "start_date", "end_date",
            "band", "version"
        ),
        bands = "class",
        labels = c(
            "1" = "ClearCut_Fire", "2" = "ClearCut_Soil",
            "3" = "ClearCut_Veg", "4" = "Forest"
        ),
        progress = FALSE
    )
    # Reclassify cube
    ro_mask <- sits_reclassify(
        cube = ro_class,
        mask = prodes2021,
        rules = list(
            "Old_Deforestation" = mask %in% c(
                "d2007", "d2008", "d2009",
                "d2010", "d2011", "d2012",
                "d2013", "d2014", "d2015",
                "d2016", "d2017", "d2018",
                "r2010", "r2011", "r2012",
                "r2013", "r2014", "r2015",
                "r2016", "r2017", "r2018",
                "d2019", "r2019", "d2020",
                "r2020", "r2021"
            ),
            "Water_Mask" = mask == "Water",
            "NonForest_Mask" = mask %in% c("NonForest", "NonForest2")
        ),
        memsize = 4,
        multicores = 2,
        output_dir = tempdir(),
        version = "ex_reclassify"
    )
}

sits documentation built on Sept. 9, 2025, 5:54 p.m.