1 コンピューター内の画像
import cv2
import matplotlib.pyplot as plt
import numpy as np
img = cv2.imread('img.png')
cv2.imshow('image', img)
cv2.waitKey(0)
cv2.destroyAllWindows()
cv2.imwrite('myimg.jpg', img)
2 ビデオの読み取りと処理
import cv2
import matplotlib.pyplot as plt
import numpy as np
vc = cv2.VideoCapture('test.mp4')
if vc.isOpened():
open, frame = vc.read()
else:
open = False
while open:
ret, frame = vc.read()
if frame is None:
break
if ret == True:
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('result', gray)
if cv2.waitKey(10) & 0xFF == 27:
break
vc.release()
cv2.destroyAllWindows()
3 ROIエリア
import cv2
import matplotlib.pyplot as plt
import numpy as np
img = cv2.imread('img.png')
img = img[0:500, 0:500]
cv2.imshow('img', img)
cv2.waitKey(0)
cv2.destroyAllWindows()
b, g, r = cv2.split(img)
img = cv2.merge((b, g, r))
4 ボーダーパディング
import cv2
import matplotlib.pyplot as plt
import numpy as np
img = cv2.imread('test.jpg')
img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
top_size, bottom_size, left_size, right_size = (100, 100, 100, 100)
replicate = cv2.copyMakeBorder(src=img, top=top_size, bottom=bottom_size, left=left_size, right=right_size,
borderType=cv2.BORDER_REPLICATE)
reflect = cv2.copyMakeBorder(src=img, top=top_size, bottom=bottom_size, left=left_size, right=right_size,
borderType=cv2.BORDER_REFLECT)
reflect101 = cv2.copyMakeBorder(src=img, top=top_size, bottom=bottom_size, left=left_size, right=right_size,
borderType=cv2.BORDER_REFLECT_101)
wrap = cv2.copyMakeBorder(src=img, top=top_size, bottom=bottom_size, left=left_size, right=right_size,
borderType=cv2.BORDER_WRAP)
constant = cv2.copyMakeBorder(src=img, top=top_size, bottom=bottom_size, left=left_size, right=right_size,
borderType=cv2.BORDER_CONSTANT, value=0)
plt.subplot(2, 3, 1), plt.imshow(img, ), plt.title('original')
plt.subplot(2, 3, 2), plt.imshow(replicate, ), plt.title('replicate')
plt.subplot(2, 3, 3), plt.imshow(reflect, ), plt.title('reflect')
plt.subplot(2, 3, 4), plt.imshow(reflect101, ), plt.title('reflect101')
plt.subplot(2, 3, 5), plt.imshow(wrap, ), plt.title('wrap')
plt.subplot(2, 3, 6), plt.imshow(constant, ), plt.title('constant')
plt.show()
5 画像融合
import cv2
import matplotlib.pyplot as plt
import numpy as np
img1 = cv2.imread('data/lena.png')
img2 = cv2.imread('data/dog.jpg')
print(img1.shape)
print(img2.shape)
img2 = cv2.resize(img2, img1.shape[:2])
res = cv2.addWeighted(img1, 0.4, img2, 0.6, 0)
cv2.imwrite('res.jpg', res)