flake8-aided fixes

examples/pic2mask.py

@@ -0,0 +1,41 @@
+# pip install pillow scikit-image
+# or
+# sudo apt install python3-pil python3-skimage
+
+from PIL import Image
+from skimage.measure import find_contours
+from matplotlib import pyplot
+import numpy
+
+from masque import Pattern, Library, Polygon
+from masque.file.gdsii import writefile
+
+#
+# Read the image into a numpy array
+#
+im = Image.open('./Desktop/Camera/IMG_20220626_091101.jpg')
+
+aa = numpy.array(im.convert(mode='L').getdata()).reshape(im.height, im.width)
+
+threshold = (aa.max() - aa.min()) / 2
+
+#
+# Find edge contours and plot them
+#
+contours = find_contours(aa, threshold)
+
+pyplot.imshow(aa)
+for contour in contours:
+    pyplot.plot(contour[:, 1], contour[:, 0], linewidth=2)
+pyplot.show(block=False)
+
+#
+# Create the layout from the contours
+#
+pat = Pattern()
+pat.shapes = [Polygon(vertices=vv) for vv in contours if len(vv) < 1_000]
+
+lib = {}
+lib['my_mask_name'] = pat
+
+writefile(lib, 'test_contours.gds', meters_per_unit=1e-9)