viewChips

Plot a grid of image and/or mask chips

Usage

viewChips(
  chpDF,
  folder,
  nSamps = 16,
  mode = "both",
  justPositive = FALSE,
  cCnt = 4,
  rCnt = 4,
  r = 1,
  g = 2,
  b = 3,
  rescale = FALSE,
  rescaleVal = 1,
  cNames,
  cColors,
  useSeed = FALSE,
  seed = 42
)

Arguments

chpDF

Data frame of chip paths created with the makeChipsDF() function.

folder

Full path or path relative to the working directory to the folder containing the image chips and associated masks. You must include the final forward slash in the path (e.g., "C:/data/chips/").

nSamps

Number of samples to include in the grid. The default is 16.

mode

Either "image", "mask" or "both". If "image", a grid is produced for the image chips only. If "mask", a grid is produced for just the masks. If "both", grids are produced for both the image chips and masks. Default is "both".

justPositive

TRUE or FALSE. If makeChips() was executed using the "Divided" mode, you can choose to only show chips that contained some pixels mapped to the positive class. The default is FALSE. This should be left to the default or set to FALSE if chips were generated using a method other than "Divided".

cCnt

Number of columns in the grid. Row X Column count must sum to the number of samples being displayed (nSamps). Default is 4.

rCnt

Number of rows in the grid. Row X Column count must sum to the number of samples being displayed (nSamps). Default is 4.

r

Band number to map to the red channel. Default is 1 or the first channel. For gray scale or single-band images, assign the same index to all three bands.

g

Band number to map to the green channel. Default is 2 or the second channel. For gray scale or single-band images, assign the same index to all three bands.

b

Band number to map to the red channel. Default is 3 or the third channel. For gray scale or single-band images, assign the same index to all three bands.

rescale

TRUE or FALSE. Whether or not to rescale image data. Default is FALSE or no rescaling.

rescaleVal

If rescale is TRUE, value used to rescale data. For example, 255 could be used to rescale the chips from 0 to 1 to 0 to 255.

cNames

Vector of class names. Class names must be provided.

cColors

Vector of colors (named colors, hex codes, or rgb()). Color used to visualize each class is matched based on position in the vector. Colors must be provided.

useSeed

TRUE or FALSE. Whether or not to set a random seed to make result reproducible (i.e., obtain the same samples). If FALSE, seed is ignored. Default is FALSE.

seed

Random seed value. Default is 42. This is ignored if useSeed is FALSE.

Value

Plot of image chip grid (if mode = "image"); plot of mask chip grid (if mode ="mask"); plot of image and mask chip grids (if model = "both").

Details

This function generates a plot of image chips and/or image masks. It serves as a means to visualize chips generated with the makeChips() or makeChipsMultiClass() function. It can be used as a check to make sure chips were generated as expected.

Examples

if (FALSE) {
viewChips(chpDF=chpDF,
          folder= "FOLDER CONTAINING CHIPS",
          nSamps = 16,
          mode = "both",
          justPositive = FALSE,
          cCnt = 4,
          rCnt = 4,
          r = 1,
          g = 2,
          b = 3,
          rescale = FALSE,
          rescaleVal = 1,
          cNames=c("Background",
                   "Building",
                   "Woodland",
                   "Water",
                   "Road"),
          cColor=c("gray",
                   "darksalmon",
                    "forestgreen",
                    "lightblue",
                    "black"),
          useSeed = FALSE,
          seed = 42)
}