Object Detection with OpenCV and CNN for beginners

1. ~OpenCV ~

2. 2 Copyright © 2020 Oracle and/or its affiliates.
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3. 3 Copyright © 2020 Oracle and/or its affiliates.
(Image Classification) (Object Detection) (Anomaly Detection)

4. 4 Copyright © 2020 Oracle and/or its affiliates.

5. 5 Copyright © 2020 Oracle and/or its affiliates.

6. Copyright © 2019, Oracle and/or its affiliates. All rights reserved. |Confidential – Oracle Internal/Restricted/Highly Restricted6

7. 7 Copyright © 2020 Oracle and/or its affiliates.
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8. 8 Copyright © 2020 Oracle and/or its affiliates.
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9. 9 Copyright © 2020 Oracle and/or its affiliates.
• Open Source Computer Vision Library
•
• Willow Garage (2009) Itseez
Itseez (2016)
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• C/C++ Java Python
• OS
• Mac OS FreeBSD POSIX Unix OS Linux
Windows Android iOS
•
OpenCV
: Wikipedia
https://ja.wikipedia.org/wiki/OpenCV

10. 10 Copyright © 2020 Oracle and/or its affiliates.
2
(Canny/Sobel/
) (findContours)
(
)

11. 11 Copyright © 2020 Oracle and/or its affiliates.
( )
( )
Canny
Homography

12. 12 Copyright © 2020 Oracle and/or its affiliates.

13. Copyright © 2019, Oracle and/or its affiliates. All rights reserved. |Confidential – Oracle Internal/Restricted/Highly Restricted13

14. 14 Copyright © 2020 Oracle and/or its affiliates.
Scikit-learn Python Anaconda
Tensorflow 2015 Google CNN
RNN Word2Vec Seq2Seq NLP
Keras TensorFlow Theano
Chainer Preferred Networks
Pytorch Facebook NLP
Caffe UC
OpenCV
SHIFT
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• k
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• SVM
• K-means
•
• Cascade
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15. 15 Copyright © 2020 Oracle and/or its affiliates.
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Cascade
+ + =
1 2 3

16. 16 Copyright © 2020 Oracle and/or its affiliates.
Cascade
/…/positive
/…/negative
/…/vector
/…/cascade
positive.vec
cascade.xml
opencv_createsamples
OpenCV
opencv_traincascade
$ mkdir positive negative cascade vector
$ du -a /.../negative/ | awk '{print $2}’ > /…/negative.txt
$ du -a /.../positive/ | awk '{print $2}’ > /…/positivelist.txt
(x Y )
(1
)
$ opencv_createsamples -show -info /…/positivelist.txt -vec /…/vector/positive.vec
-num 500 -maxidev 40 -maxxangle 0.8 -maxyangle 0.8 -maxzangle 0.5
Cascade
$ opencv_traincascade -data cascade -vec /…/vector/positive.vec -bg
neg/neglist.txt -numPos 70 -numNeg 60
OpenCV
positivelist.txt
01.jpg 1 0 0 200 200 ← x Y

17. 17 Copyright © 2020 Oracle and/or its affiliates.
Cascade (OpenCV Python )
# OpenCV
import cv2
#
# OpenCV (xml )
face_cascade = cv2.CascadeClassifier(‘haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier(‘haarcascade_eye.xml’)
#
img = cv2.imread(‘my_face.jpg’)
img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
# ( ) Rect(x,y,w,h)
faces = face_cascade.detectMultiScale(img_gray)
#
for x, y, w, h in faces:
cv2.rectangle(img, (x, y), (x + w, y + h), (255, 0, 0), 2)
face = img[y: y + h, x: x + w]
face_gray = img_gray[y: y + h, x: x + w]
eyes = eye_cascade.detectMultiScale(face_gray) #
for (ex, ey, ew, eh) in eyes:
cv2.rectangle(face, (ex, ey), (ex + ew, ey + eh), (0, 255, 0), 2)
haarcascade_frontalface_default.xml
( Cascade )
haarcascade_eye.xml
( Cascade )
Cascade

18. 18 Copyright © 2020 Oracle and/or its affiliates.

19. 19 Copyright © 2020 Oracle and/or its affiliates.
: Wikipedia
https://ja.wikipedia.org/wiki/%E7%A5%9E%E7%B5%8C%E7%B4%B0%E8%83%9E
• ニューロン：神経細胞
• シナプス：ニューロンと他のニューロンとの接合部分
• ニューロン間の結合（シナプス結合)：あるニューロンから別の
ニューロンへ信号が伝達される状態。
• 活性化：あるニューロンが受け取った刺激の大きさが特定の大きさを
超えると、そのニューロンは次のニューロンへと信号を伝達する。こ
の状態を活性化と呼ぶ。
• ノード：ニューロンに相当する。重みとバイアスを持つ。
• エッジ：シナプス結合に相当する。ノード間を接続する。
• 重み、バイアス：シナプス結合の強度。ノード間接続時の信号の大きさの
計算に利用される。
• 活性化関数：活性化を表す関数。次ノードへ伝える値を決める関数。

20. 20 Copyright © 2020 Oracle and/or its affiliates.
CNN ( )
• 28x28 /
• 6
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0 9 0 9
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• 1
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21. 21 Copyright © 2020 Oracle and/or its affiliates.
( ) 28
28
784 x 1
768
28x28
( : 0 – 255/ )

22. 22 Copyright © 2020 Oracle and/or its affiliates.
CNN
784
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768 x 1
input
input
input
input

23. 23 Copyright © 2020 Oracle and/or its affiliates.

24. 24 Copyright © 2020 Oracle and/or its affiliates.
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25. 25 Copyright © 2020 Oracle and/or its affiliates.
OpenCV Org
https://docs.opencv.org/master/index.html
OpenCV
https://opencv-python-tutroals.readthedocs.io/en/latest/
TensorFlow GPU
https://blogs.oracle.com/bigdata-dataintegration-jp/tfwgpu
Oracle Cloud Infrastructure Data Science
https://blogs.oracle.com/bigdata-dataintegration-jp/oracle-cloud-infrastructure-data-science