1 files changed, 65 insertions, 0 deletions
diff --git a/scan.py b/scan.py
new file mode 100644
index 0000000..75e14bb
--- /dev/null
+++ b/scan.py
@@ -0,0 +1,65 @@
+import cv2
+import imutils
+import numpy as np
+
+
+def order_points(pts):
+    rect = np.zeros((4, 2), dtype="float32")
+    s = pts.sum(axis=1)
+    rect[0] = pts[np.argmin(s)]
+    rect[2] = pts[np.argmax(s)]
+    diff = np.diff(pts, axis=1)
+    rect[1] = pts[np.argmin(diff)]
+    rect[3] = pts[np.argmax(diff)]
+    return rect
+
+
+def four_point_transform(image, pts):
+    rect = order_points(pts)
+    (tl, tr, br, bl) = rect
+    widthA = np.sqrt(((br[0] - bl[0]) ** 2) + ((br[1] - bl[1]) ** 2))
+    widthB = np.sqrt(((tr[0] - tl[0]) ** 2) + ((tr[1] - tl[1]) ** 2))
+    maxWidth = max(int(widthA), int(widthB))
+
+    heightA = np.sqrt(((tr[0] - br[0]) ** 2) + ((tr[1] - br[1]) ** 2))
+    heightB = np.sqrt(((tl[0] - bl[0]) ** 2) + ((tl[1] - bl[1]) ** 2))
+    maxHeight = max(int(heightA), int(heightB))
+
+    dst = np.array([
+        [0, 0],
+        [maxWidth - 1, 0],
+        [maxWidth - 1, maxHeight - 1],
+        [0, maxHeight - 1]], dtype="float32")
+
+    M = cv2.getPerspectiveTransform(rect, dst)
+    warped = cv2.warpPerspective(image, M, (maxWidth, maxHeight))
+
+    return warped
+
+
+image = cv2.imread("example.jpg")
+ratio = image.shape[0] / 500.0
+orig = image.copy()
+
+gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
+gray = cv2.GaussianBlur(gray, (5, 5), 0)
+edged = cv2.Canny(gray, 75, 200)
+
+cnts = cv2.findContours(edged.copy(), cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
+cnts = imutils.grab_contours(cnts)
+cnts = sorted(cnts, key=cv2.contourArea, reverse=True)[:5]
+
+for c in cnts:
+    peri = cv2.arcLength(c, True)
+    approx = cv2.approxPolyDP(c, 0.02 * peri, True)
+    if len(approx) == 4:
+        screenCnt = approx
+        break
+
+cv2.drawContours(image, [screenCnt], -1, (0, 255, 0), 2)
+
+warped = four_point_transform(orig, screenCnt.reshape(4, 2) * ratio)
+
+cv2.imshow("Original", imutils.resize(orig, height=650))
+cv2.imshow("Scanned", imutils.resize(warped, height=650))
+cv2.waitKey(0)