samples: fix python samples compatibility with demo.py

samples/python/mouse_and_match.py

@@ -25,59 +25,64 @@ import argparse
 from math import *
 
 
-drag_start = None
-sel = (0,0,0,0)
+class App():
+    drag_start = None
+    sel = (0,0,0,0)
+
+    def onmouse(self, event, x, y, flags, param):
+        if event == cv.EVENT_LBUTTONDOWN:
+            self.drag_start = x, y
+            self.sel = (0,0,0,0)
+        elif event == cv.EVENT_LBUTTONUP:
+            if self.sel[2] > self.sel[0] and self.sel[3] > self.sel[1]:
+                patch = self.gray[self.sel[1]:self.sel[3], self.sel[0]:self.sel[2]]
+                result = cv.matchTemplate(self.gray, patch, cv.TM_CCOEFF_NORMED)
+                result = np.abs(result)**3
+                _val, result = cv.threshold(result, 0.01, 0, cv.THRESH_TOZERO)
+                result8 = cv.normalize(result, None, 0, 255, cv.NORM_MINMAX, cv.CV_8U)
+                cv.imshow("result", result8)
+            self.drag_start = None
+        elif self.drag_start:
+            #print flags
+            if flags & cv.EVENT_FLAG_LBUTTON:
+                minpos = min(self.drag_start[0], x), min(self.drag_start[1], y)
+                maxpos = max(self.drag_start[0], x), max(self.drag_start[1], y)
+                self.sel = (minpos[0], minpos[1], maxpos[0], maxpos[1])
+                img = cv.cvtColor(self.gray, cv.COLOR_GRAY2BGR)
+                cv.rectangle(img, (self.sel[0], self.sel[1]), (self.sel[2], self.sel[3]), (0,255,255), 1)
+                cv.imshow("gray", img)
+            else:
+                print("selection is complete")
+                self.drag_start = None
+
+    def run(self):
+        parser = argparse.ArgumentParser(description='Demonstrate mouse interaction with images')
+        parser.add_argument("-i","--input", default='../data/', help="Input directory.")
+        args = parser.parse_args()
+        path = args.input
+
+        cv.namedWindow("gray",1)
+        cv.setMouseCallback("gray", self.onmouse)
+        '''Loop through all the images in the directory'''
+        for infile in glob.glob( os.path.join(path, '*.*') ):
+            ext = os.path.splitext(infile)[1][1:] #get the filename extension
+            if ext == "png" or ext == "jpg" or ext == "bmp" or ext == "tiff" or ext == "pbm":
+                print(infile)
+
+                img = cv.imread(infile,1)
+                if img is None:
+                    continue
+                self.sel = (0,0,0,0)
+                self.drag_start = None
+                self.gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
+                cv.imshow("gray", self.gray)
+                if cv.waitKey() == 27:
+                    break
+
+        print('Done')
 
-def onmouse(event, x, y, flags, param):
-    global drag_start, sel
-    if event == cv.EVENT_LBUTTONDOWN:
-        drag_start = x, y
-        sel = 0,0,0,0
-    elif event == cv.EVENT_LBUTTONUP:
-        if sel[2] > sel[0] and sel[3] > sel[1]:
-            patch = gray[sel[1]:sel[3],sel[0]:sel[2]]
-            result = cv.matchTemplate(gray,patch,cv.TM_CCOEFF_NORMED)
-            result = np.abs(result)**3
-            _val, result = cv.threshold(result, 0.01, 0, cv.THRESH_TOZERO)
-            result8 = cv.normalize(result,None,0,255,cv.NORM_MINMAX,cv.CV_8U)
-            cv.imshow("result", result8)
-        drag_start = None
-    elif drag_start:
-        #print flags
-        if flags & cv.EVENT_FLAG_LBUTTON:
-            minpos = min(drag_start[0], x), min(drag_start[1], y)
-            maxpos = max(drag_start[0], x), max(drag_start[1], y)
-            sel = minpos[0], minpos[1], maxpos[0], maxpos[1]
-            img = cv.cvtColor(gray, cv.COLOR_GRAY2BGR)
-            cv.rectangle(img, (sel[0], sel[1]), (sel[2], sel[3]), (0,255,255), 1)
-            cv.imshow("gray", img)
-        else:
-            print("selection is complete")
-            drag_start = None
 
 if __name__ == '__main__':
     print(__doc__)
-
-    parser = argparse.ArgumentParser(description='Demonstrate mouse interaction with images')
-    parser.add_argument("-i","--input", default='../data/', help="Input directory.")
-    args = parser.parse_args()
-    path = args.input
-
-    cv.namedWindow("gray",1)
-    cv.setMouseCallback("gray", onmouse)
-    '''Loop through all the images in the directory'''
-    for infile in glob.glob( os.path.join(path, '*.*') ):
-        ext = os.path.splitext(infile)[1][1:] #get the filename extension
-        if ext == "png" or ext == "jpg" or ext == "bmp" or ext == "tiff" or ext == "pbm":
-            print(infile)
-
-            img=cv.imread(infile,1)
-            if img is None:
-                continue
-            sel = (0,0,0,0)
-            drag_start = None
-            gray=cv.cvtColor(img, cv.COLOR_BGR2GRAY)
-            cv.imshow("gray",gray)
-            if cv.waitKey() == 27:
-                break
+    App().run()
     cv.destroyAllWindows()