Add algorithms/context-adaptive_interpolator.py

algorithms/context-adaptive_interpolator.py

@@ -0,0 +1,26 @@
+from PIL import Image
+from statistics import mean
+
+# What about other color channels?
+image = Image.open('9f04e2005fddb9d5512e2f42a3b826b019755717.jpg').convert('L')
+newI = image.load()
+I = image.copy().load()
+DEFAULT_COLOR = 255
+# This threshold is debatable.
+THRESHOLD = 20
+# How to manage the border of the image?
+for m in range(1, image.size[0] - 1):
+    for n in range(1, image.size[1] - 1):
+            e = I[m, n + 1]
+            se = I[m + 1, n + 1]
+            s = I[m + 1, n]
+            sw = I[m + 1, n - 1]
+            w = I[m, n - 1]
+            nw = I[m - 1, n - 1]
+            no = I[m - 1, n]
+            ne = I[m - 1, n + 1]
+            A = [e, se, s, sw, w, nw, no, ne]
+            if max(A) - min(A) <= THRESHOLD:
+                newI[m, n] = int(round(I[m, n] - mean(A), 0))
+
+image.show()