Adds new functions to plotBoxes.R that crop images and save them to an output file

R/plotBoxes.R

@@ -58,3 +58,67 @@ plotBoxes <- function(image, label = FALSE, minconf = 0) {
     }
   }
 }
+
+library(magick)
+#' Crops a jpg image using a precalculated bounding box
+#'
+#' @param imagePath The path for the image
+#' @param bbox1 bounding box coordinate corresponding to the left edge of the box
+#' @param bbox2 bounding box coordinate corresponding to the bottom edge of the box
+#' @param bbox3 bounding box coordinate corresponding to the right edge of the box
+#' @param bbox4 bounding box coordinate corresponding to the top edge of the box
+#'
+#' @return no return value, outputs the cropped image
+#' @export
+#'
+#' @examples
+#' \dontrun{
+#' cropJpg("/image/path/image.jpg", "/output/path/", 0.1, 0.2, 0.6, 0.8)
+#' }
+cropJpg <- function(imagePath, outputPath, bbox1, bbox2, bbox3, bbox4) {
+  image <- image_read(imagePath)
+  info <- image_info(image)
+  width <- info$width
+  height <- info$height
+
+  xleft <- bbox1 * width
+  ybottom <- height - bbox2 * height
+  xright <- (bbox1 + bbox3) * width
+  ytop <- height - (bbox2 + bbox4) * height
+
+  width <- xright - xleft
+  height <- ybottom - ytop
+
+  dimensions <- paste(width, height, sep="x")
+  dimensions <- paste(dimensions, xleft, ytop, sep="+")
+  cropped <- image_crop(image, dimensions)
+
+  split_image_path_vector <- strsplit(imagePath, "/")
+  image_name <- split_image_path_vector[[1]][length(split_image_path_vector[[1]])]
+  output_path <- paste(outputPath, image_name)
+  image_write(cropped, path = output_path, format = "png")
+}
+
+#' Crops all images from an input file with specific required columns: Frame,
+#' bbox1, bbox2, bbox3, and bbox4
+#'
+#' @param csvFilePath The path for the input csv file
+#' @param outputPath The path where generated cropped images should be uploaded
+#'
+#' @return no return value, outputs the cropped image
+#' @export
+#'
+#' @examples
+#' \dontrun{
+#' cropImagesFromFile("/image/path/file.csv", "/output/path/")
+#' }
+cropImagesFromFile <- function(csvFilePath, outputPath) {
+  uncropped_data <- read.csv(csvFilePath)
+  df = data.frame(uncropped_data)
+  df <- as.data.frame(sapply(df, function(x) gsub("\"", "", x))) # Removes extra quotation marks
+
+  # for-loop over rows
+  for(i in 1:nrow(df)) { 
+    cropJpg(df[i,]$Frame,outputPath,as.numeric(df[i,]$bbox1),as.numeric(df[i,]$bbox2),as.numeric(df[i,]$bbox3),as.numeric(df[i,]$bbox4))
+  }
+}