Add sample seven seg variations, and preset operations to prepair them for OCR

Author: Nipuna Sudharaka

learn-opencv.py

@@ -47,6 +47,7 @@ def initTool():
 img_cropped = cv2.morphologyEx(img_cropped, cv2.MORPH_CLOSE, kernel)
 img_cropped = cv2.morphologyEx(img_cropped, cv2.MORPH_OPEN, kernel)
 # ------------------------
+# ------------------------
 txt = tool.image_to_string(
     CV2PIL(img_cropped),
     lang=lang,

preprocessings.py

@@ -0,0 +1,55 @@
+# ============================= ONE (light red chars on dark red background)===============
+
+# img_ori = cv2.imread('processing/digits copy.jpg')
+img_ori = cv2.imread('processing/digits-dot.jpg')
+img_cropped = img_ori[146:201, 48: 304].copy()
+img_marked = cv2.rectangle(img_ori, (48, 146), (304, 201), (0, 255, 0), 1)
+
+img_cropped = cv2.medianBlur(img_cropped, 5)
+img_cropped = cv2.cvtColor(img_cropped, cv2.COLOR_BGR2GRAY)
+img_cropped = cv2.bitwise_not(img_cropped)
+img_cropped = cv2.adaptiveThreshold(img_cropped, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, 7, 2)
+cv2.imshow("after threshold", img_cropped)
+cv2.moveWindow("after threshold", 50, 650)
+# ------------------------
+kernel = np.ones((3, 3), np.uint8)  # building a kernel, a unit of operation
+# --------------------------------
+img_cropped = cv2.morphologyEx(img_cropped, cv2.MORPH_CLOSE, kernel)
+img_cropped = cv2.morphologyEx(img_cropped, cv2.MORPH_OPEN, kernel)
+# ------------------------
+
+# ============================= TWO (pure red char on black)================================
+
+img_cropped = cv2.medianBlur(img_cropped, 5)
+# img_cropped = cv2.cvtColor(img_cropped, cv2.COLOR_BGR2GRAY)
+img_cropped = cv2.cvtColor(img_cropped, cv2.COLOR_BGR2HSV)
+lower_red = np.array([0, 50, 50])
+upper_red = np.array([15, 255, 255])
+
+img_cropped = cv2.inRange(img_cropped, lower_red, upper_red)
+
+img_cropped = cv2.bitwise_not(img_cropped)
+# ------------------------
+kernel = np.ones((3, 3), np.uint8)  # building a kernel, a unit of operation
+# --------------------------------
+img_cropped = cv2.morphologyEx(img_cropped, cv2.MORPH_CLOSE, kernel)
+img_cropped = cv2.morphologyEx(img_cropped, cv2.MORPH_OPEN, kernel)
+# ------------------------
+
+#============================== THREE (too bright digits, off segments visible)
+
+img_cropped = cv2.medianBlur(img_cropped, 5)
+lower_red = np.array([0, 0, 200])
+upper_red = np.array([50, 255, 255])
+
+ret, img_cropped = cv2.threshold(img_cropped, 127, 255, cv2.THRESH_BINARY)
+cv2.imshow("after threshold", img_cropped)
+cv2.moveWindow("after threshold", 50, 650)
+img_cropped = cv2.bitwise_not(img_cropped)
+img_cropped = cv2.cvtColor(img_cropped, cv2.COLOR_BGR2GRAY)
+ret, img_cropped = cv2.threshold(img_cropped, 127, 255, cv2.THRESH_BINARY)
+# ------------------------
+kernel = np.ones((3, 3), np.uint8)  # building a kernel, a unit of operation
+# --------------------------------
+img_cropped = cv2.morphologyEx(img_cropped, cv2.MORPH_CLOSE, kernel)
+img_cropped = cv2.morphologyEx(img_cropped, cv2.MORPH_OPEN, kernel)

processing/digits2.jpg

@@ -1,3 +1,5 @@
 numpy
 pyocr
-pillow
+pillow
+tesseract
+pytesseract