python cv2:

simple video capture and synth framework stub
edge detection sample

samples/python2/edge.py

@@ -0,0 +1,29 @@
+import cv2, cv
+import video
+import sys
+
+try: fn = sys.argv[1]
+except: fn = 'synth:bg=../cpp/lena.jpg:noise=0.1'
+
+def nothing(*arg):
+    pass
+
+cv2.namedWindow('edge')
+cv.CreateTrackbar('thrs1', 'edge', 2000, 5000, nothing)
+cv.CreateTrackbar('thrs2', 'edge', 4000, 5000, nothing)
+
+cap = video.create_capture(fn)
+while True:
+    flag, img = cap.read()
+    gray = cv2.cvtColor(img, cv.CV_BGR2GRAY)
+    thrs1 = cv2.getTrackbarPos('thrs1', 'edge')
+    thrs2 = cv2.getTrackbarPos('thrs2', 'edge')
+    edge = cv2.canny(gray, thrs1, thrs2, apertureSize=5)
+    vis = img.copy()
+    vis /= 2
+    vis[edge != 0] = (0, 255, 0)
+    cv2.imshow('edge', vis)
+    ch = cv2.waitKey(5)
+    if ch == 27:
+        break
+

samples/python2/video.py

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+import numpy as np
+import cv2
+
+class VideoSynth(object):
+    def __init__(self, size=None, noise=0.0, bg = None, **params):
+        self.bg = None
+        self.frame_size = (640, 480)
+        if bg is not None:
+            self.bg = cv2.imread(bg, 1)
+            h, w = self.bg.shape[:2]
+            self.frame_size = (w, h)
+            
+        if size is not None:
+            w, h = map(int, size.split('x'))
+            self.frame_size = (w, h)
+            self.bg = cv2.resize(bg, self.frame_size)
+
+        self.noise = float(noise)
+
+    def read(self, dst=None):
+        w, h = self.frame_size
+
+        buf = np.zeros((h, w, 3), np.uint8)
+        if self.bg is not None:
+            buf[:] = self.bg
+        if self.noise > 0.0:
+            noise = np.random.normal(scale = 255*self.noise, size=(h, w, 3))
+            buf = cv2.add(buf, noise, dtype=cv2.CV_8UC3)
+        return True, buf
+
+
+def create_capture(source):
+    '''
+      source: <int> or '<int>' or '<filename>' or 'synth:<params>'
+    '''
+    try: source = int(source)
+    except ValueError: pass
+    else:
+        return cv2.VideoCapture(source)
+    source = str(source).strip()
+    if source.startswith('synth'):
+        ss = filter(None, source.split(':'))
+        params = dict( s.split('=') for s in ss[1:] )
+        return VideoSynth(**params)
+    return cv2.VideoCapture(source)
+
+
+if __name__ == '__main__':
+    import sys
+    try: fn = sys.argv[1]
+    except: fn = 'synth:bg=../cpp/lena.jpg:noise=0.1'
+
+    cap = create_capture(fn)
+    while True:
+        ret, img = cap.read()
+        cv2.imshow('img', img)
+        ch = cv2.waitKey(1)
+        if ch == 27:
+            break