diff --git a/y2020/vision/ball_detection.py b/y2020/vision/ball_detection.py
new file mode 100644
index 0000000..46faccc
--- /dev/null
+++ b/y2020/vision/ball_detection.py
@@ -0,0 +1,31 @@
+#!/usr/bin/python3
+
+from rect import Rect
+
+import cv2 as cv
+import numpy as np
+
+# This function finds the percentage of yellow pixels in the rectangles
+# given that are regions of the given image. This allows us to determine
+# whether there is a ball in those rectangles
+def pct_yellow(img, rects):
+    hsv = cv.cvtColor(img, cv.COLOR_BGR2HSV)
+    lower_yellow = np.array([23, 100, 75], dtype = np.uint8)
+    higher_yellow = np.array([40, 255, 255], dtype = np.uint8)
+    mask = cv.inRange(hsv, lower_yellow, higher_yellow)
+
+    pcts = np.zeros(len(rects))
+    for i in range(len(rects)):
+        rect = rects[i]
+        slice = mask[rect.y1 : rect.y2, rect.x1 : rect.x2]
+        yellow_px = np.count_nonzero(slice)
+        pcts[i] = 100 * (yellow_px / (slice.shape[0] * slice.shape[1]))
+
+    return pcts
+
+def capture_img():
+    video_stream = cv.VideoCapture(0)
+    frame = video_stream.read()[1]
+    video_stream.release()
+    frame = cv.cvtColor(frame, cv.COLOR_BGR2RGB)
+    return frame