ch4-ch9

Author: makelove

__init__.py

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+__author__ = 'play'

ch4/4.1_imread_imshow.py

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+# -*- coding: utf-8 -*-
+
+import numpy as np
+import cv2
+
+# Load an color image in grayscale
+img = cv2.imread('messi5.jpg',0)
+
+cv2.namedWindow('image',cv2.WINDOW_NORMAL)
+cv2.imshow('image',img)
+cv2.waitKey(0)
+cv2.destroyAllWindows()
+
+#
+cv2.imwrite('messigray.png',img)

ch4/4.imread_imshow_imwrite.py

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+import numpy as np
+import cv2
+
+img = cv2.imread('messi5.jpg',0)
+cv2.imshow('image',img)
+k = cv2.waitKey(0)
+if k == 27:         # wait for ESC key to exit
+    cv2.destroyAllWindows()
+elif k == ord('s'): # wait for 's' key to save and exit
+    cv2.imwrite('messigray.png',img)
+    cv2.destroyAllWindows()

ch4/4.matplotlib.py

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+import numpy as np
+import cv2
+from matplotlib import pyplot as plt
+
+img = cv2.imread('messi5.jpg',0)
+plt.imshow(img, cmap = 'gray', interpolation = 'bicubic')
+plt.xticks([]), plt.yticks([])  # to hide tick values on X and Y axis
+plt.show()

ch4/messi5.jpg

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+# -*- coding: utf-8 -*-
+"""
+Created on Fri Jan 3 21:06:22 2014
+
+@author: duan
+ """
+
+import numpy as np
+import cv2
+
+cap = cv2.VideoCapture(0)
+# while (True):
+while (cap.isOpened()):
+    # Capture frame-by-frame
+    ret, frame = cap.read()
+
+    # Our operations on the frame come here
+    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
+
+    # Display the resulting frame
+    cv2.imshow('frame', gray)
+    if cv2.waitKey(1) & 0xFF == ord('q'):
+        break
+
+# When everything done, release the capture
+cap.release()
+cv2.destroyAllWindows()

ch4/messigray.png

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+import numpy as np
+import cv2
+
+cap = cv2.VideoCapture('vtest.avi')
+
+while(cap.isOpened()):
+    ret, frame = cap.read()
+
+    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
+
+    cv2.imshow('frame',gray)
+    if cv2.waitKey(1) & 0xFF == ord('q'):
+        break
+
+cap.release()
+cv2.destroyAllWindows()

ch5/5.VideoCapture.py

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+import numpy as np
+import cv2
+
+cap = cv2.VideoCapture(0)
+
+# Define the codec and create VideoWriter object
+fourcc = cv2.VideoWriter_fourcc(*'XVID')#opencv 3.0
+#Error: 'module' object has no attribute 'VideoWriter_fourcc'
+#
+out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
+
+while(cap.isOpened()):
+    ret, frame = cap.read()
+    if ret==True:
+        frame = cv2.flip(frame,0)
+
+        # write the flipped frame
+        out.write(frame)
+
+        cv2.imshow('frame',frame)
+        if cv2.waitKey(1) & 0xFF == ord('q'):
+            break
+    else:
+        break
+
+# Release everything if job is finished
+cap.release()
+out.release()
+cv2.destroyAllWindows()

ch5/5.VideoPlay.py

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+__author__ = 'play'

ch5/5.VideoWriter.py

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+# -*- coding: utf-8 -*-
+import numpy as np
+import cv2
+
+# Create a black image
+img = np.zeros((512, 512, 3), np.uint8)
+
+
+# Draw a diagonal blue line with thickness of 5 px
+cv2.line(img, (0, 0), (511, 511), (255, 0, 0), 5)
+
+cv2.rectangle(img, (384, 0), (510, 128), (0, 255, 0), 3)
+
+cv2.circle(img, (447, 63), 63, (0, 0, 255), -1)
+
+cv2.ellipse(img, (256, 256), (100, 50), 0, 0, 180, 255, -1)
+
+pts = np.array([[10, 5], [20, 30], [70, 20], [50, 10]], np.int32)
+pts = pts.reshape((-1, 1, 2))
+# 这里 reshape 的第一个参数为-1, 表明这一维的长度是根据后面的维度的计算出来的。
+
+font=cv2.FONT_HERSHEY_SIMPLEX
+cv2.putText(img,'OpenCV',(10,500), font, 4,(255,255,255),2)
+
+winname = 'example'
+cv2.namedWindow(winname, 0)
+cv2.imshow(winname, img)
+cv2.waitKey(0)
+cv2.destroyAllWindows()

ch5/__init__.py

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+# -*- coding: utf-8 -*-
+import cv2
+import numpy as np
+
+
+# mouse callback function
+
+
+def draw_circle(event, x, y, flags, param):
+    if event == cv2.EVENT_LBUTTONDBLCLK:
+        cv2.circle(img, (x, y), 100, (255, 0, 0), -1)
+
+
+# 创建图像与窗口并将窗口与回调函数绑定
+img = np.zeros((512, 512, 3), np.uint8)
+cv2.namedWindow('image',0)
+cv2.setMouseCallback('image', draw_circle)
+while (1):
+    cv2.imshow('image', img)
+    if cv2.waitKey(20) & 0xFF == 27:
+        break
+cv2.destroyAllWindows()

ch6/6.draw.py

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+# -*- coding: utf-8 -*-
+import cv2
+import numpy as np
+# 当鼠标按下时变为 True
+drawing = False
+# 如果 mode 为 true 绘制矩形。按下'm' 变成绘制曲线。 mode=True
+ix, iy = -1, -1
+
+
+# 创建回调函数
+def draw_circle(event, x, y, flags, param):
+    global ix, iy, drawing, mode
+    # 当按下左键是返回起始位置坐标
+    if event == cv2.EVENT_LBUTTONDOWN:
+        drawing = True
+        ix, iy = x, y
+    # 当鼠标左键按下并移动是绘制图形。event 可以查看移动,flag 查看是否按下
+    elif event == cv2.EVENT_MOUSEMOVE and flags == cv2.EVENT_FLAG_LBUTTON:
+        if drawing == True:
+            if mode == True:
+                cv2.rectangle(img, (ix, iy), (x, y), (0, 255, 0), -1)
+            else:
+                # 绘制圆圈,小圆点连在一起就成了线,3 代表了笔画的粗细
+                cv2.circle(img, (x, y), 3, (0, 0, 255), -1)
+                # 下面注释掉的代码是起始点为圆心,起点到终点为半径的
+                # r = int(np.sqrt((x - ix) ** 2 + (y - iy) ** 2))
+                # cv2.circle(img, (x, y), r, (0, 0, 255), -1)
+                # 当鼠标松开停止绘画。
+    elif event == cv2.EVENT_LBUTTONUP:
+        drawing == False
+        # if mode == True:
+        #     cv2.rectangle(img, (ix, iy), (x, y), (0, 255, 0), -1)
+        # else:
+        #     cv2.circle(img, (x, y), 5, (0, 0, 255), -1)
+
+
+#
+img = np.zeros((512, 512, 3), np.uint8)
+mode=False
+
+cv2.namedWindow('image', 0)
+cv2.setMouseCallback('image', draw_circle)
+while (1):
+    cv2.imshow('image', img)
+    k = cv2.waitKey(1) & 0xFF
+    if k == ord('m'):
+        mode = not mode
+    elif k == 27:
+        break

ch7/7.MouseCallback.py

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+# -*- coding: utf-8 -*-
+import cv2
+import numpy as np
+
+
+def nothing(x):
+    pass
+
+
+# 当鼠标按下时变为 True
+drawing = False
+# 如果 mode 为 true 绘制矩形。按下'm' 变成绘制曲线。 mode=True
+ix, iy = -1, -1
+
+
+# 创建回调函数
+def draw_circle(event, x, y, flags, param):
+    r = cv2.getTrackbarPos('R', 'image')
+    g = cv2.getTrackbarPos('G', 'image')
+    b = cv2.getTrackbarPos('B', 'image')
+    color = (b, g, r)
+
+    global ix, iy, drawing, mode
+    # 当按下左键是返回起始位置坐标
+    if event == cv2.EVENT_LBUTTONDOWN:
+        drawing = True
+        ix, iy = x, y
+    # 当鼠标左键按下并移动是绘制图形。event 可以查看移动,flag 查看是否按下
+    elif event == cv2.EVENT_MOUSEMOVE and flags == cv2.EVENT_FLAG_LBUTTON:
+        if drawing == True:
+            if mode == True:
+                cv2.rectangle(img, (ix, iy), (x, y), color, -1)
+            else:
+                # 绘制圆圈,小圆点连在一起就成了线,3 代表了笔画的粗细
+                cv2.circle(img, (x, y), 3, color, -1)
+                # 下面注释掉的代码是起始点为圆心,起点到终点为半径的
+                # r=int(np.sqrt((x-ix)**2+(y-iy)**2))
+                # cv2.circle(img,(x,y),r,(0,0,255),-1)
+
+                # 当鼠标松开停止绘画。
+    elif event == cv2.EVENT_LBUTTONUP:
+        drawing == False
+        # if mode==True:
+        #     cv2.rectangle(img,(ix,iy),(x,y),(0,255,0),-1)
+        # else:
+        #     cv2.circle(img,(x,y),5,(0,0,255),-1)
+
+
+img = np.zeros((512, 512, 3), np.uint8)
+mode=False
+
+cv2.namedWindow('image')
+cv2.createTrackbar('R', 'image', 0, 255, nothing)
+cv2.createTrackbar('G', 'image', 0, 255, nothing)
+cv2.createTrackbar('B', 'image', 0, 255, nothing)
+cv2.setMouseCallback('image', draw_circle)
+while (1):
+    cv2.imshow('image', img)
+    k = cv2.waitKey(1) & 0xFF
+    if k == ord('m'):
+        mode = not mode
+    elif k == 27:
+        break

ch7/7.draw_circle_rectangle.py

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+# -*- coding: utf-8 -*-
+
+import cv2
+import numpy as np
+
+def nothing(x):
+    pass
+
+# Create a black image, a window
+img = np.zeros((300,512,3), np.uint8)
+cv2.namedWindow('image')
+
+# create trackbars for color change
+cv2.createTrackbar('R','image',0,255,nothing)
+cv2.createTrackbar('G','image',0,255,nothing)
+cv2.createTrackbar('B','image',0,255,nothing)
+
+# create switch for ON/OFF functionality
+switch = '0 : OFF \n1 : ON'
+cv2.createTrackbar(switch, 'image',0,1,nothing)
+
+while(1):
+    cv2.imshow('image',img)
+    k = cv2.waitKey(1) & 0xFF
+    if k == 27:
+        break
+
+    # get current positions of four trackbars
+    r = cv2.getTrackbarPos('R','image')
+    g = cv2.getTrackbarPos('G','image')
+    b = cv2.getTrackbarPos('B','image')
+    s = cv2.getTrackbarPos(switch,'image')
+
+    if s == 0:
+        img[:] = 0
+    else:
+        img[:] = [b,g,r]
+
+cv2.destroyAllWindows()