script to crop equirectangular images with overlap

1 files changed, 55 insertions, 0 deletions

diff --git a/crop-equirectangular.py b/crop-equirectangular.py
new file mode 100644
index 0000000..683cba8
--- /dev/null
+++ b/crop-equirectangular.py
@@ -0,0 +1,55 @@
+import os
+import glob
+import requests
+import time
+from PIL import Image
+
+# This script should be run once to generate crops with a specific aspect ratio from a pano.
+
+parser = argparse.ArgumentParser()
+parser.add_argument('--folder', default="sequences/venice_360/equi")
+parser.add_argument('--label', required=True)
+parser.add_argument('--vertical_offset', type=int, default=983)
+parser.add_argument('--overlap', type=float, default=0.5)
+opt = parser.parse_args()
+
+src_width = 4096
+src_height = 2048
+
+count = 3
+output_aspect = 3
+
+overall_aspect = count * output_aspect
+overlapped_aspect = overall_aspect - count * opt.overlap
+crop_width = src_width * output_aspect / overlapped_aspect
+crop_height = crop_width / output_aspect
+
+c0 = 7/6 * crop_width
+c1 = 3/6 * crop_width
+c2 = 5/6 * crop_width
+
+x0 = c0 - crop_width / 2
+x1 = c1 - crop_width / 2
+x2 = c2 - crop_width / 2
+
+y0 = opt.vertical_offset - crop_height / 2
+
+p0 = (x0, y0, x0 + crop_width, y0 + crop_height,)
+p1 = (x1, y0, x1 + crop_width, y0 + crop_height,)
+p2 = (x2, y0, x2 + crop_width, y0 + crop_height,)
+
+path_0 = os.path.join("sequences", label + "_a")
+path_1 = os.path.join("sequences", label + "_b")
+path_2 = os.path.join("sequences", label + "_c")
+
+for i, fn in enumerate(glob(os.path.join(opt.folder, '*.png'))):
+  fn = "frame_{:04d}.png".format(i)
+
+  canvas = Image.new('RGB', (src_width, src_height * 3/2,))
+  image = Image.open(fn)
+  canvas.paste(image, (0, 0))
+  canvas.paste(image, (src_width, 0))
+
+  canvas.crop(p0).resize((1024, 512,), Image.ANTIALIAS).save(os.path.join(path_0, fn))
+  canvas.crop(p1).resize((1024, 512,), Image.ANTIALIAS).save(os.path.join(path_1, fn))
+  canvas.crop(p2).resize((1024, 512,), Image.ANTIALIAS).save(os.path.join(path_2, fn))