code: def main():
      parser = argparse.ArgumentParser(
          description="Contrast check script"
      )
      parser.add_argument(
          "--per_channel", dest="per_channel", action="store_true"
      )
      args = parser.parse_args()
  
      augs = []
      for p in [0.25, 0.5, 1.0, 2.0, (0.5, 1.5), [0.5, 1.0, 1.5]]:
          augs.append(
              (
                  "GammaContrast " + str(p),
                  iaa.GammaContrast(p, per_channel=args.per_channel),
              )
          )
  
      for cutoff in [0.25, 0.5, 0.75]:
          for gain in [5, 10, 15, 20, 25]:
              augs.append(
                  (
                      "SigmoidContrast "
                      + str(cutoff)
                      + " "
                      + str(gain),
                      iaa.SigmoidContrast(
                          gain, cutoff, per_channel=args.per_channel
                      ),
                  )
              )
  
      for gain in [
          0.0,
          0.25,
          0.5,
          1.0,
          2.0,
          (0.5, 1.5),
          [0.5, 1.0, 1.5],
      ]:
          augs.append(
              (
                  "LogContrast " + str(gain),
                  iaa.LogContrast(gain, per_channel=args.per_channel),
              )
          )
  
      for alpha in [
          -1.0,
          0.5,
          0,
          0.5,
          1.0,
          2.0,
          (0.5, 1.5),
          [0.5, 1.0, 1.5],
      ]:
          augs.append(
              (
                  "LinearContrast " + str(alpha),
                  iaa.LinearContrast(
                      alpha, per_channel=args.per_channel
                  ),
              )
          )
  
      augs.append(
          (
              "AllChannelsHistogramEqualization",
              iaa.AllChannelsHistogramEqualization(),
          )
      )
      augs.append(
          (
              "HistogramEqualization (Lab)",
              iaa.HistogramEqualization(
                  to_colorspace=iaa.HistogramEqualization.Lab
              ),
          )
      )
      augs.append(
          (
              "HistogramEqualization (HSV)",
              iaa.HistogramEqualization(
                  to_colorspace=iaa.HistogramEqualization.HSV
              ),
          )
      )
      augs.append(
          (
              "HistogramEqualization (HLS)",
              iaa.HistogramEqualization(
                  to_colorspace=iaa.HistogramEqualization.HLS
              ),
          )
      )
  
      for clip_limit in [0.1, 1, 5, 10]:
          for tile_grid_size_px in [3, 7]:
              augs.append(
                  (
                      "AllChannelsCLAHE %d %dx%d"
                      % (
                          clip_limit,
                          tile_grid_size_px,
                          tile_grid_size_px,
                      ),
                      iaa.AllChannelsCLAHE(
                          clip_limit=clip_limit,
                          tile_grid_size_px=tile_grid_size_px,
                          per_channel=args.per_channel,
                      ),
                  )
              )
  
      for clip_limit in [1, 5, 10, 100, 200]:
          for tile_grid_size_px in [3, 7, 15]:
              augs.append(
                  (
                      "CLAHE %d %dx%d"
                      % (
                          clip_limit,
                          tile_grid_size_px,
                          tile_grid_size_px,
                      ),
                      iaa.CLAHE(
                          clip_limit=clip_limit,
                          tile_grid_size_px=tile_grid_size_px,
                      ),
                  )
              )
  
      images = [data.astronaut()] * 16
      images = ia.imresize_many_images(np.uint8(images), (128, 128))
      for name, aug in augs:
          print("-----------")
          print(name)
          print("-----------")
          images_aug = aug.augment_images(images)
          images_aug[0] = images[0]
          grid = ia.draw_grid(images_aug, rows=4, cols=4)
          ia.imshow(grid)
  
imports: from __future__ import print_function, division
  import argparse
  import numpy
  from skimage import data
  import imgaug
  from imgaug import augmenters
label_desc: Use image node_id 1 for calling a global function with example usage: main() without return types