R/api_plot_raster.R

In e-sensing/sits: Satellite Image Time Series Analysis for Earth Observation Data Cubes

#' @title  Plot a false color image
#' @name   .plot_false_color
#' @author Gilberto Camara, \email{gilberto.camara@@inpe.br}
#' @description plots a set of false color image
#' @keywords internal
#' @noRd
#' @param  tile          Tile to be plotted.
#' @param  band          Band to be plotted.
#' @param  date          Date to be plotted.
#' @param  sf_seg        Segments (sf object)
#' @param  seg_color     Color to use for segment borders
#' @param  line_width    Line width to plot the segments boundary
#' @param  palette       A sequential RColorBrewer palette
#' @param  rev           Reverse the color palette?
#' @param  scale         Scale to plot map (0.4 to 1.0)
#' @param  max_cog_size  Maximum size of COG overviews (lines or columns)
#' @param  first_quantile First quantile for stretching images
#' @param  last_quantile  Last quantile for stretching images
#' @param  tmap_params   List with tmap params for detailed plot control
#' @return               A list of plot objects
.plot_false_color <- function(tile,
                              band,
                              date,
                              sf_seg,
                              seg_color,
                              line_width,
                              palette,
                              rev,
                              scale,
                              max_cog_size,
                              first_quantile,
                              last_quantile,
                              tmap_params) {
    # select the file to be plotted
    bw_file <- .tile_path(tile, band, date)
    # size of data to be read
    sizes <- .tile_overview_size(tile = tile, max_cog_size)
    # scale and offset
    band_conf <- .tile_band_conf(tile, band)
    band_scale <- .scale(band_conf)
    band_offset <- .offset(band_conf)
    max_value <- .max_value(band_conf)
    # retrieve the overview if COG
    bw_file <- .gdal_warp_file(bw_file, sizes)

    # read raster data as a stars object

    st <- stars::read_stars(bw_file,
        along = "band",
        RasterIO = list(
            nBufXSize = sizes[["xsize"]],
            nBufYSize = sizes[["ysize"]]
        ),
        proxy = FALSE
    )
    st <- st * band_scale + band_offset
    # extract the values
    vals <- as.vector(st[[1]])
    # obtain the quantiles
    quantiles <- stats::quantile(
        vals,
        probs = c(0, first_quantile, last_quantile, 1),
        na.rm = TRUE
    )
    minv <- quantiles[[1]]
    minq <- quantiles[[2]]
    maxq <- quantiles[[3]]
    maxv <- quantiles[[4]]

    vals <- ifelse(vals > minq, vals, minq)
    vals <- ifelse(vals < maxq, vals, maxq)
    st[[1]] <- vals

    p <- .tmap_false_color(
        st = st,
        band = band,
        sf_seg = sf_seg,
        seg_color = seg_color,
        line_width = line_width,
        palette = palette,
        rev = rev,
        scale = scale,
        tmap_params = tmap_params
        )
    return(p)

}

#' @title  Plot a multi-date band as RGB
#' @name   .plot_band_multidate
#' @author Gilberto Camara, \email{gilberto.camara@@inpe.br}
#' @description plots a set of false color image
#' @keywords internal
#' @noRd
#' @param  tile          Tile to be plotted.
#' @param  band          Band to be plotted.
#' @param  dates         Dates to be plotted.
#' @param  palette       A sequential RColorBrewer palette
#' @param  rev           Reverse the color palette?
#' @param  scale         Scale to plot map (0.4 to 1.0)
#' @param  max_cog_size  Maximum size of COG overviews (lines or columns)
#' @param  first_quantile First quantile for stretching images
#' @param  last_quantile  Last quantile for stretching images
#' @param  tmap_params   List with tmap params for detailed plot control
#'
#' @return               A list of plot objects
#'
.plot_band_multidate <- function(tile,
                                 band,
                                 dates,
                                 palette,
                                 rev,
                                 scale,
                                 max_cog_size,
                                 first_quantile,
                                 last_quantile,
                                 tmap_params) {
    # select the files to be plotted
    red_file   <- .tile_path(tile, band, dates[[1]])
    green_file <- .tile_path(tile, band, dates[[2]])
    blue_file  <- .tile_path(tile, band, dates[[3]])
    sizes <- .tile_overview_size(tile = tile, max_cog_size)
    # get the max values
    band_params <- .tile_band_conf(tile, band)
    max_value <- .max_value(band_params)
    # used for SAR images without tiling system
    if (tile[["tile"]] == "NoTilingSystem")  {
        red_file   <- .gdal_warp_file(red_file, sizes)
        green_file <- .gdal_warp_file(green_file, sizes)
        blue_file  <- .gdal_warp_file(blue_file, sizes)
    }
    # plot multitemporal band as RGB
    p <- .plot_rgb_stars(
            red_file = red_file,
            green_file = green_file,
            blue_file = blue_file,
            sizes = sizes,
            max_value = max_value,
            sf_seg = NULL,
            seg_color = NULL,
            line_width = NULL,
            scale = scale,
            first_quantile = first_quantile,
            last_quantile = last_quantile,
            tmap_params = tmap_params
    )
    return(p)
}
#' @title  Plot a RGB image
#' @name   .plot_rgb
#' @author Gilberto Camara, \email{gilberto.camara@@inpe.br}
#' @keywords internal
#' @noRd
#' @param  tile          Tile to be plotted
#' @param  red           Band to be plotted in red
#' @param  green         Band to be plotted in green
#' @param  blue          Band to be plotted in blue
#' @param  date          Date to be plotted
#' @param  sf_seg        Segments (sf object)
#' @param  seg_color     Color to use for segment borders
#' @param  line_width    Line width to plot the segments boundary
#' @param  scale         Scale to plot map (0.4 to 1.0)
#' @param  max_cog_size  Maximum size of COG overviews (lines or columns)
#' @param  first_quantile First quantile for stretching images
#' @param  last_quantile  Last quantile for stretching images
#' @param  tmap_params   List with tmap params for detailed plot control
#' @return               A plot object
#'
.plot_rgb <- function(tile,
                      red,
                      green,
                      blue,
                      date,
                      sf_seg,
                      seg_color,
                      line_width,
                      scale,
                      max_cog_size,
                      first_quantile,
                      last_quantile,
                      tmap_params) {
    # get RGB files for the requested timeline
    red_file <- .tile_path(tile, red, date)
    green_file <- .tile_path(tile, green, date)
    blue_file <- .tile_path(tile, blue, date)

    # get the max values
    band_params <- .tile_band_conf(tile, red)
    max_value <- .max_value(band_params)
    # size of data to be read
    sizes <- .tile_overview_size(tile = tile, max_cog_size)
    # used for SAR images
    if (tile[["tile"]] == "NoTilingSystem") {
        red_file   <- .gdal_warp_file(red_file, sizes)
        green_file <- .gdal_warp_file(green_file, sizes)
        blue_file  <- .gdal_warp_file(blue_file, sizes)
    }
    p <- .plot_rgb_stars(
        red_file = red_file,
        green_file = green_file,
        blue_file = blue_file,
        sizes = sizes,
        max_value = max_value,
        sf_seg = sf_seg,
        seg_color = seg_color,
        line_width = line_width,
        scale = scale,
        first_quantile = first_quantile,
        last_quantile = last_quantile,
        tmap_params = tmap_params
    )
    return(p)
}
#' @title  Plot a RGB image using stars and tmap
#' @name   .plot_rgb_stars
#' @author Gilberto Camara, \email{gilberto.camara@@inpe.br}
#' @keywords internal
#' @noRd
#' @param  red_file      File to be plotted in red
#' @param  green_file    File to be plotted in green
#' @param  blue_file     File to be plotted in blue
#' @param  sizes         Image sizes for overview
#' @param  max_value     Maximum value
#' @param  sf_seg        Segments (sf object)
#' @param  seg_color     Color to use for segment borders
#' @param  line_width    Line width to plot the segments boundary
#' @param  scale         Scale to plot map (0.4 to 1.0)
#' @param  first_quantile First quantile for stretching images
#' @param  last_quantile  Last quantile for stretching images
#' @param  tmap_params   List with tmap params for detailed plot control
#' @return               A plot object
#'
.plot_rgb_stars <- function(red_file,
                            green_file,
                            blue_file,
                            sizes,
                            max_value,
                            sf_seg,
                            seg_color,
                            line_width,
                            scale,
                            first_quantile,
                            last_quantile,
                            tmap_params) {

    # read raster data as a stars object with separate RGB bands
    rgb_st <- stars::read_stars(
        c(red_file, green_file, blue_file),
        along = "band",
        RasterIO = list(
            nBufXSize = sizes[["xsize"]],
            nBufYSize = sizes[["ysize"]]
        ),
        proxy = FALSE
    )
    # open RGB stars
    rgb_st <- stars::st_rgb(rgb_st[, , , 1:3],
                            dimension = "band",
                            maxColorValue = max_value,
                            use_alpha = FALSE,
                            probs = c(first_quantile,
                                      last_quantile),
                            stretch = TRUE
    )

    p <- .tmap_rgb_color(
        rgb_st = rgb_st,
        scale = scale,
        tmap_params = tmap_params,
        sf_seg = sf_seg,
        seg_color = seg_color,
        line_width = line_width
    )
    return(p)
}
#' @title  Plot a classified image
#' @name   .plot_class_image
#' @author Gilberto Camara, \email{gilberto.camara@@inpe.br}
#' @description plots a classified image
#' @keywords internal
#' @noRd
#' @param  tile          Tile to be plotted.
#' @param  legend        Legend for the classes
#' @param  palette       A sequential RColorBrewer palette
#' @param  scale         Scale to plot the map
#' @param  max_cog_size  Maximum size of COG overviews (lines or columns)
#' @param  tmap_params   List with tmap params for detailed plot control
#' @return               A plot object
#'
.plot_class_image <- function(tile, legend, palette,
                              scale, max_cog_size, tmap_params) {
    # verifies if stars package is installed
    .check_require_packages("stars")
    # verifies if tmap package is installed
    .check_require_packages("tmap")
    # deal with color palette
    .check_palette(palette)
    # get the labels
    labels <- .cube_labels(tile)
    # obtain the colors
    colors <- .colors_get(
        labels = labels,
        legend = legend,
        palette = palette,
        rev = TRUE
    )
    # prepare colors, labels and ids for plotting
    colors_plot <- tibble::tibble(
        label_id = names(labels),
        label    = unname(labels),
        color    = unname(colors)
    )
    # size of data to be read
    sizes <- .tile_overview_size(tile = tile, max_cog_size)
    # select the image to be plotted
    class_file <- .tile_path(tile)
    # read file
    st <- stars::read_stars(
        class_file,
        RasterIO = list(
            nBufXSize = sizes[["xsize"]],
            nBufYSize = sizes[["ysize"]]
        ),
        proxy = FALSE
    )
    # rename stars object and set variables as factor
    st <- stats::setNames(st, "labels")
    st[["labels"]] <- factor(
        st[["labels"]],
        labels = colors_plot[["label"]],
        levels = colors_plot[["label_id"]]
    )
    p <- .tmap_class_map(
        st = st,
        colors = colors_plot,
        scale = scale,
        tmap_params = tmap_params
    )
    return(p)
}
#' @title  Plot probs
#' @name   .plot_probs
#' @author Gilberto Camara, \email{gilberto.camara@@inpe.br}
#' @keywords internal
#' @noRd
#' @param  tile          Probs cube to be plotted.
#' @param  labels_plot   Labels to be plotted
#' @param  palette       A sequential RColorBrewer palette
#' @param  rev           Reverse the color palette?
#' @param  scale         Global scale for plot
#' @param  tmap_params   Parameters for tmap
#' @param  max_cog_size  Maximum size of COG overviews (lines or columns)
#' @return               A plot object
#'
.plot_probs <- function(tile,
                        labels_plot,
                        palette,
                        rev,
                        scale,
                        tmap_params,
                        max_cog_size) {
    # set caller to show in errors
    .check_set_caller(".plot_probs")
    # verifies if stars package is installed
    .check_require_packages("stars")
    # verifies if tmap package is installed
    .check_require_packages("tmap")
    # precondition - check color palette
    .check_palette(palette)
    # get all labels to be plotted
    labels <- .tile_labels(tile)
    names(labels) <- seq_len(length(labels))
    # check the labels to be plotted
    # if NULL, use all labels
    if (.has_not(labels_plot)) {
        labels_plot <- labels
    } else {
        .check_that(all(labels_plot %in% labels))
    }
    # size of data to be read
    max_size <- .conf("plot", "max_size")
    sizes <- .tile_overview_size(tile = tile, max_cog_size)
    # get the path
    probs_path <- .tile_path(tile)
    # read the file using stars
    probs_st <- stars::read_stars(
        probs_path,
        RasterIO = list(
            nBufXSize = sizes[["xsize"]],
            nBufYSize = sizes[["ysize"]]
        ),
        proxy = FALSE
    )
    # get the band
    band <- .tile_bands(tile)
    band_conf <- .tile_band_conf(tile, band)
    # scale the data
    probs_st <- probs_st * .scale(band_conf)

    # rename stars object dimensions to labels
    probs_st <- stars::st_set_dimensions(probs_st,
                                         "band", values = labels)

    p <- .tmap_probs_map(
        probs_st = probs_st,
        labels = labels,
        labels_plot = labels_plot,
        palette = palette,
        rev = rev,
        scale = scale,
        tmap_params = tmap_params
    )
    return(p)
}
#' @title  Plot variance histogram
#' @name   .plot_variance_hist
#' @author Gilberto Camara, \email{gilberto.camara@@inpe.br}
#' @keywords internal
#' @noRd
#' @param  tile          Variance cube to be plotted.
#'
#' @return               A plot object
#'
.plot_variance_hist <- function(tile) {
    # get all labels to be plotted
    labels <- .tile_labels(tile)
    # get the path
    var_path <- .tile_path(tile)
    # get the bounding box as an sf object
    sf_cube <- .bbox_as_sf(.bbox(tile))
    # numbers of nrows and ncols
    nrows <- .tile_nrows(tile)
    ncols <- .tile_ncols(tile)
    # sample the pixels
    n_samples <- as.integer(nrows / 5 * ncols / 5)
    points <- sf::st_sample(sf_cube, size = n_samples)
    points <- sf::st_coordinates(points)
    # get the r object
    r_obj <- .raster_open_rast(var_path)
    # read the file
    values <- .raster_extract(r_obj, points)
    # scale the data
    band_conf <- .conf_derived_band(
        derived_class = "variance_cube",
        band = "variance"
    )
    scale <- .scale(band_conf)
    if (.has(scale) && scale != 1) {
        values <- values * scale
    }
    offset <- .offset(band_conf)
    if (.has(offset) && offset != 0) {
        values <- values + offset
    }
    # convert to tibble
    values <- tibble::as_tibble(values)
    # include label names
    colnames(values) <- labels
    # dissolve the data for plotting
    values <- tidyr::pivot_longer(values,
        cols = tidyr::everything(),
        names_to = "labels",
        values_to = "variance"
    )
    # Histogram with density plot
    p <- ggplot2::ggplot(
        values,
        ggplot2::aes(x = .data[["variance"]])
    ) +
        ggplot2::geom_histogram(
            binwidth = 1,
            fill = "#69b3a2",
            color = "#e9ecef",
            alpha = 0.9
        ) +
        ggplot2::scale_x_continuous()
    p <- p + ggplot2::facet_wrap(facets = "labels")

    return(p)
}