OpenCV with Python Blueprints

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Welcome to the "OpenCV with Python Blueprints" group!

This is the place to discuss and ask questions about the following book:

M. Beyeler (2015). "OpenCV with Python Blueprints: Design and develop advanced computer vision projects using OpenCV with Python". Packt Publishing Ltd., London, England, 230 pages, ISBN 978-178528269-0.

All source code is available on GitHub.

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petar.m....@gmail.com, … Michael Beyeler8

8/6/20

metaclass conflict

The second edition of the book should provide a more modern solution: https://github.com/

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metaclass conflict

The second edition of the book should provide a more modern solution: https://github.com/

8/6/20

12/19/18

Mask two images with python

Hello there, How do I supper impose an image design on a transparent png image? I have tried to use

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Mask two images with python

Hello there, How do I supper impose an image design on a transparent png image? I have tried to use

12/19/18

Zhang Xun, Michael Beyeler2

12/11/18

python cv2 feature matching give different results

Hi, You're not the only one having this problem. FLANN uses some probabilistic method to find the

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python cv2 feature matching give different results

Hi, You're not the only one having this problem. FLANN uses some probabilistic method to find the

12/11/18

Goli, Michael Beyeler2

12/11/18

input videos in tensorflow. TypeError: Required argument 'mat' (pos 2) not found

The problem seems to be that video3d wants a second argument mat, which you did not provide (last

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input videos in tensorflow. TypeError: Required argument 'mat' (pos 2) not found

The problem seems to be that video3d wants a second argument mat, which you did not provide (last

12/11/18

Goli, Michael Beyeler2

12/11/18

why does cv2.imread change the pixel values?

Hi, You didn't post the output of these calls, so it's hard to know what went wrong with this

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why does cv2.imread change the pixel values?

Hi, You didn't post the output of these calls, so it's hard to know what went wrong with this

12/11/18

degrou...@gmail.com, Michael Beyeler3

6/5/18

Creating cx_Freeze exe with cv2

Hi, Thanks for posting. Unfortunately, I'm not familiar with cxFreeze - here we mainly discuss

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Creating cx_Freeze exe with cv2

Hi, Thanks for posting. Unfortunately, I'm not familiar with cxFreeze - here we mainly discuss

6/5/18

G10DRAS, … Michael Beyeler5

5/4/18

How to train multiple datasets/faces_training-*.pkl files with train_test_mlp.py script ?

Hi, In short, you need to assemble a training set first using the app. The .pkl file will then be

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How to train multiple datasets/faces_training-*.pkl files with train_test_mlp.py script ?

Hi, In short, you need to assemble a training set first using the app. The .pkl file will then be

5/4/18

4/2/18

Chapter 4- undistorted

Hi, Why are the images undistorted first and then - at _find_camera_matrices_rt() - calculating

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Chapter 4- undistorted

Hi, Why are the images undistorted first and then - at _find_camera_matrices_rt() - calculating

4/2/18

Vedant Shah, Michael Beyeler2

3/13/18

Unable to train

Hi Vedant, Any chance you're running OpenCV 3.1? In newer version of OpenCV, PCACompute requires

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Unable to train

Hi Vedant, Any chance you're running OpenCV 3.1? In newer version of OpenCV, PCACompute requires

3/13/18

Mateus Arruda, Michael Beyeler2

3/2/18

3D Reconstruction from multiple Images

On Friday, January 19, 2018 at 3:46:08 PM UTC-7, Mateus Arruda wrote: Hi! I've been studying from

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3D Reconstruction from multiple Images

On Friday, January 19, 2018 at 3:46:08 PM UTC-7, Mateus Arruda wrote: Hi! I've been studying from

3/2/18

tizian...@gmail.com

1/14/18

OpenCV Error: Unspecified error

Hi Michael, I create the faces_preprocessed.pkl and mlp.xml but running chapter7.py in the phase of

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OpenCV Error: Unspecified error

Hi Michael, I create the faces_preprocessed.pkl and mlp.xml but running chapter7.py in the phase of

1/14/18

ibrahim...@gmail.com, Michael Beyeler2

5/16/17

Chapter7 When I click take snapshot button, I take type error.

Hi Ibrahim, Python 2 can be a bit finicky when it comes to slicing arrays: It wants the indices to be

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Chapter7 When I click take snapshot button, I take type error.

Hi Ibrahim, Python 2 can be a bit finicky when it comes to slicing arrays: It wants the indices to be

5/16/17

4/5/17

Hello Michael. I'm Jason from Korea. i did read your book. and have a question. i want analyze of

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Hello Michael. I'm Jason from Korea. i did read your book. and have a question. i want analyze of

4/5/17

goodw...@daum.net, Michael Beyeler2

2/28/17

Hi, Thanks for posting the error messages. Is it possible that you're using OpenCV 3 (possibly

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Hi, Thanks for posting the error messages. Is it possible that you're using OpenCV 3 (possibly

2/28/17

goodw...@daum.net, … 상범박9

2/28/17

i have some questins about chapter7

I am running chapter7.py. I had installed opencv.However, these errors occur. There is a lot of

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i have some questins about chapter7

I am running chapter7.py. I had installed opencv.However, these errors occur. There is a lot of

2/28/17

VINOD BATTINI, Michael Beyeler2

2/21/17

Hi Vinod, A good place to start would be to find a publicly available dataset that shows traffic

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Hi Vinod, A good place to start would be to find a publicly available dataset that shows traffic

2/21/17

Aman Dalmia, Michael Beyeler2

1/19/17

Query on NDVI image

Hi Aman, Here's a possible outline: Convert to HSV. Find the distribution (range) of HSV values

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Query on NDVI image

Hi Aman, Here's a possible outline: Convert to HSV. Find the distribution (range) of HSV values

1/19/17

Cool Brin, Michael Beyeler2

12/27/16

Demo Failure : Cannot detect face with funcntion face_cascade.detectMultiScale()

Hi, If the pre-trained Haar classifier doesn't detect a face in your image, there are a few

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Demo Failure : Cannot detect face with funcntion face_cascade.detectMultiScale()

Hi, If the pre-trained Haar classifier doesn't detect a face in your image, there are a few

12/27/16

proletaria...@gmail.com, Michael Beyeler3

12/6/16

Hi, Michael. I don't understand the function "_in_front_of_both_cameras" in Chapter4.

Thanks, Micheal. I have browsed through the chapter on epipolar geometry of Hartley & Zisserman,

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Hi, Michael. I don't understand the function "_in_front_of_both_cameras" in Chapter4.

Thanks, Micheal. I have browsed through the chapter on epipolar geometry of Hartley & Zisserman,

12/6/16

Michael Beyeler2

12/6/16

How to install wxPython on Mac OS X 10.11 El Capitan?

User Phuong P. on Amazon reported that wxPython 3.0.3 (and forward?) is the way to go: This wxPython

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How to install wxPython on Mac OS X 10.11 El Capitan?

User Phuong P. on Amazon reported that wxPython 3.0.3 (and forward?) is the way to go: This wxPython

12/6/16

Laurent, Michael Beyeler2

11/29/16

ValueError: too many values to unpack when running chapter 5 code

Hi Laurent, Thanks for your comment! I'm glad you're enjoying the book. Any chance you're

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ValueError: too many values to unpack when running chapter 5 code

Hi Laurent, Thanks for your comment! I'm glad you're enjoying the book. Any chance you're

11/29/16

Sam Lee, Michael Beyeler5

10/4/16

Fail to install Python3x and OpenCV 3

If anyone is still having problems with OpenCV 3 and Python 3.5, the easiest way is probably to go

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Fail to install Python3x and OpenCV 3

If anyone is still having problems with OpenCV 3 and Python 3.5, the easiest way is probably to go

10/4/16

mike nesius, Michael Beyeler2

9/30/16

ch 6 Memory Error MCS.fit(X_train, y_train)

Hi Mike, This is a tricky one... Here are some comments and ideas, hopefully one of them will work

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ch 6 Memory Error MCS.fit(X_train, y_train)

Hi Mike, This is a tricky one... Here are some comments and ideas, hopefully one of them will work

9/30/16

赵东城, Michael Beyeler4

5/13/16

some questions about chapter 7

You're welcome. Let me know if you run into any other issues. On Friday, May 13, 2016 at 4:16:29

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some questions about chapter 7

You're welcome. Let me know if you run into any other issues. On Friday, May 13, 2016 at 4:16:29

5/13/16

Dietrich Dehlinger, Michael Beyeler3

5/2/16

Adventures in open CV

Well, I am unable to get SURF to work on a standard PC running linux as well. From what I can tell

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Adventures in open CV

Well, I am unable to get SURF to work on a standard PC running linux as well. From what I can tell

5/2/16

Zhicheng Cui, Michael Beyeler2

4/28/16

cv2_imread can not load JPEG

Hi Zhicheng, You are correct: >>> myJpg = cv2.imread('myfile.jpg') is the right way

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cv2_imread can not load JPEG

Hi Zhicheng, You are correct: >>> myJpg = cv2.imread('myfile.jpg') is the right way

4/28/16

as6...@g.rit.edu, Michael Beyeler2

4/23/16

How to get reconstruction output in chapter 4 ?

Hi, Hmmm, your output definitely looks weird. This is what you got from running >>> python

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How to get reconstruction output in chapter 4 ?

Hi, Hmmm, your output definitely looks weird. This is what you got from running >>> python

4/23/16

Luis Assunção, Michael Beyeler4

4/23/16

Sugestion of a new chapter

Hi Luis, I have not gotten a chance to write it yet, but it will appear over at www.askaswiss.com! I

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Sugestion of a new chapter

Hi Luis, I have not gotten a chance to write it yet, but it will appear over at www.askaswiss.com! I

4/23/16

G10DRAS, Michael Beyeler3

2/21/16

Chapter7 code for Raspbian Whizzy ?

I tried latest code on Raspbian Whizzy (ARM7) but result is same ie not working. The following code

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Chapter7 code for Raspbian Whizzy ?

I tried latest code on Raspbian Whizzy (ARM7) but result is same ie not working. The following code

2/21/16

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