how to extract x,y coordinates from OpenCV “cv2.keypoint” object?

I tried to use the following code:

    xCoordinate=point.x

(point is type of cv2.keyPoint)
It gives me error saying cv2.keyPoint has no attribute 'x'

asked Mar 9 '16 at 6:21

mengmengxyz

1442510

add a comment |

I tried to use the following code:

    xCoordinate=point.x

(point is type of cv2.keyPoint)
It gives me error saying cv2.keyPoint has no attribute 'x'

asked Mar 9 '16 at 6:21

mengmengxyz

1442510

add a comment |

I tried to use the following code:

    xCoordinate=point.x

(point is type of cv2.keyPoint)
It gives me error saying cv2.keyPoint has no attribute 'x'

asked Mar 9 '16 at 6:21

mengmengxyz

1442510

I tried to use the following code:

    xCoordinate=point.x

(point is type of cv2.keyPoint)
It gives me error saying cv2.keyPoint has no attribute 'x'

python opencv numpy

asked Mar 9 '16 at 6:21

mengmengxyz

1442510

asked Mar 9 '16 at 6:21

mengmengxyz

1442510

asked Mar 9 '16 at 6:21

mengmengxyz

1442510

asked Mar 9 '16 at 6:21

mengmengxyz

1442510

asked Mar 9 '16 at 6:21

mengmengxyz

1442510

add a comment |

5 Answers
5

active

oldest

votes

You can use:

import numpy as np



pts = np.float([kp[idx].pt for idx in len(kp)]).reshape(-1, 1, 2)

pts will be an array of keypoints.

answered Mar 9 '16 at 8:40

Francesco Nazzaro

1,809617

add a comment |

point.pt is a tuple(x,y)`.

So,

x = point.pt[0]

y = point.pt[1]

or,

(x,y) = point.pt

edited Dec 22 '18 at 4:45

skumhest

answered May 6 '17 at 8:13

saikat sarkar

9114

add a comment |

Read the docs.

class KeyPoint

Data structure for salient point detectors.

Point2f pt
-- coordinates of the keypoint

float size
-- diameter of the meaningful keypoint neighborhood

float angle ...¶

So point.pt is a Point2f.

Try x,y= point.pt

edited Nov 20 '18 at 2:05

answered Mar 9 '16 at 6:37

roadrunner66

3,74321834

point.pt.x is invalid, please correct it as: x, y = point.pt

– Nirmal
Oct 26 '18 at 5:30

add a comment |

Here is my take (runable code):

import cv2, os

import numpy as np

import matplotlib.pyplot as plt



# INITIALISATION

filename = os.path.join('foo', 'bar.jpg')

img0 = cv2.imread(filename) # original image

gray = cv2.cvtColor(img0, cv2.COLOR_BGR2GRAY) # convert to grayscale

sift = cv2.xfeatures2d.SIFT_create() # initialize SIFT 

f, (ax1, ax2) = plt.subplots(1, 2) # create subplots



# DETECT AND DRAW KEYPOINTS

# sift.detect() returns a list of keypoints

# keypoint is a standard class of opencv (not just SIFT-related)

kp = sift.detect(gray,None) # calculates SIFT points

img1=cv2.drawKeypoints(gray,kp, None) # mae new image with keypoints drawn

ax1.imshow(img1) # plot 



# RETREIVE KEYPOINTS COORDINATES AND DRAW MANUALLY

# Reade these and make numpy array

pts = np.asarray([[p.pt[0], p.pt[1]] for p in kp])

cols = pts[:,0]

rows = pts[:,1]

ax2.imshow(cv2.cvtColor(img0, cv2.COLOR_BGR2RGB))

ax2.scatter(cols, rows)



plt.show()

edited Nov 2 '18 at 12:58

answered Nov 2 '18 at 10:40

quickbug

1,65931117

add a comment |

I solved your problem like this.

kp,des = surf.detectAndCompute(img,None) 

pts = [p.pt for p in kp]

Now you get a list of x,y co-ordinates for all keypoints in your image.

edited Oct 6 '17 at 9:06

Shaido

12.6k122541

answered Oct 6 '17 at 8:49

Alexander Hunt

add a comment |

Your Answer

StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});

}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f35884409%2fhow-to-extract-x-y-coordinates-from-opencv-cv2-keypoint-object%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

5 Answers
5

active

oldest

votes

5 Answers
5

active

oldest

votes

You can use:

import numpy as np



pts = np.float([kp[idx].pt for idx in len(kp)]).reshape(-1, 1, 2)

pts will be an array of keypoints.

answered Mar 9 '16 at 8:40

Francesco Nazzaro

1,809617

add a comment |

You can use:

import numpy as np



pts = np.float([kp[idx].pt for idx in len(kp)]).reshape(-1, 1, 2)

pts will be an array of keypoints.

answered Mar 9 '16 at 8:40

Francesco Nazzaro

1,809617

add a comment |

You can use:

import numpy as np



pts = np.float([kp[idx].pt for idx in len(kp)]).reshape(-1, 1, 2)

pts will be an array of keypoints.

answered Mar 9 '16 at 8:40

Francesco Nazzaro

1,809617

You can use:

import numpy as np



pts = np.float([kp[idx].pt for idx in len(kp)]).reshape(-1, 1, 2)

pts will be an array of keypoints.

answered Mar 9 '16 at 8:40

Francesco Nazzaro

1,809617

answered Mar 9 '16 at 8:40

Francesco Nazzaro

1,809617

answered Mar 9 '16 at 8:40

Francesco Nazzaro

1,809617

answered Mar 9 '16 at 8:40

Francesco Nazzaro

1,809617

add a comment |

point.pt is a tuple(x,y)`.

So,

x = point.pt[0]

y = point.pt[1]

or,

(x,y) = point.pt

edited Dec 22 '18 at 4:45

skumhest

answered May 6 '17 at 8:13

saikat sarkar

9114

add a comment |

point.pt is a tuple(x,y)`.

So,

x = point.pt[0]

y = point.pt[1]

or,

(x,y) = point.pt

edited Dec 22 '18 at 4:45

skumhest

answered May 6 '17 at 8:13

saikat sarkar

9114

add a comment |

point.pt is a tuple(x,y)`.

So,

x = point.pt[0]

y = point.pt[1]

or,

(x,y) = point.pt

edited Dec 22 '18 at 4:45

skumhest

answered May 6 '17 at 8:13

saikat sarkar

9114

point.pt is a tuple(x,y)`.

So,

x = point.pt[0]

y = point.pt[1]

or,

(x,y) = point.pt

edited Dec 22 '18 at 4:45

skumhest

answered May 6 '17 at 8:13

saikat sarkar

9114

edited Dec 22 '18 at 4:45

skumhest

edited Dec 22 '18 at 4:45

skumhest

edited Dec 22 '18 at 4:45

skumhest

answered May 6 '17 at 8:13

saikat sarkar

9114

answered May 6 '17 at 8:13

saikat sarkar

9114

answered May 6 '17 at 8:13

saikat sarkar

9114

add a comment |

Read the docs.

class KeyPoint

Data structure for salient point detectors.

Point2f pt
-- coordinates of the keypoint

float size
-- diameter of the meaningful keypoint neighborhood

float angle ...¶

So point.pt is a Point2f.

Try x,y= point.pt

edited Nov 20 '18 at 2:05

answered Mar 9 '16 at 6:37

roadrunner66

3,74321834

point.pt.x is invalid, please correct it as: x, y = point.pt

– Nirmal
Oct 26 '18 at 5:30

add a comment |

Read the docs.

class KeyPoint

Data structure for salient point detectors.

Point2f pt
-- coordinates of the keypoint

float size
-- diameter of the meaningful keypoint neighborhood

float angle ...¶

So point.pt is a Point2f.

Try x,y= point.pt

edited Nov 20 '18 at 2:05

answered Mar 9 '16 at 6:37

roadrunner66

3,74321834

point.pt.x is invalid, please correct it as: x, y = point.pt

– Nirmal
Oct 26 '18 at 5:30

add a comment |

Read the docs.

class KeyPoint

Data structure for salient point detectors.

Point2f pt
-- coordinates of the keypoint

float size
-- diameter of the meaningful keypoint neighborhood

float angle ...¶

So point.pt is a Point2f.

Try x,y= point.pt

edited Nov 20 '18 at 2:05

answered Mar 9 '16 at 6:37

roadrunner66

3,74321834

Read the docs.

class KeyPoint

Data structure for salient point detectors.

Point2f pt
-- coordinates of the keypoint

float size
-- diameter of the meaningful keypoint neighborhood

float angle ...¶

So point.pt is a Point2f.

Try x,y= point.pt

edited Nov 20 '18 at 2:05

answered Mar 9 '16 at 6:37

roadrunner66

3,74321834

edited Nov 20 '18 at 2:05

answered Mar 9 '16 at 6:37

roadrunner66

3,74321834

answered Mar 9 '16 at 6:37

roadrunner66

3,74321834

answered Mar 9 '16 at 6:37

roadrunner66

3,74321834

point.pt.x is invalid, please correct it as: x, y = point.pt

– Nirmal
Oct 26 '18 at 5:30

add a comment |

point.pt.x is invalid, please correct it as: x, y = point.pt

– Nirmal
Oct 26 '18 at 5:30

point.pt.x is invalid, please correct it as: x, y = point.pt

– Nirmal
Oct 26 '18 at 5:30

add a comment |

Here is my take (runable code):

import cv2, os

import numpy as np

import matplotlib.pyplot as plt



# INITIALISATION

filename = os.path.join('foo', 'bar.jpg')

img0 = cv2.imread(filename) # original image

gray = cv2.cvtColor(img0, cv2.COLOR_BGR2GRAY) # convert to grayscale

sift = cv2.xfeatures2d.SIFT_create() # initialize SIFT 

f, (ax1, ax2) = plt.subplots(1, 2) # create subplots



# DETECT AND DRAW KEYPOINTS

# sift.detect() returns a list of keypoints

# keypoint is a standard class of opencv (not just SIFT-related)

kp = sift.detect(gray,None) # calculates SIFT points

img1=cv2.drawKeypoints(gray,kp, None) # mae new image with keypoints drawn

ax1.imshow(img1) # plot 



# RETREIVE KEYPOINTS COORDINATES AND DRAW MANUALLY

# Reade these and make numpy array

pts = np.asarray([[p.pt[0], p.pt[1]] for p in kp])

cols = pts[:,0]

rows = pts[:,1]

ax2.imshow(cv2.cvtColor(img0, cv2.COLOR_BGR2RGB))

ax2.scatter(cols, rows)



plt.show()

edited Nov 2 '18 at 12:58

answered Nov 2 '18 at 10:40

quickbug

1,65931117

add a comment |

Here is my take (runable code):

import cv2, os

import numpy as np

import matplotlib.pyplot as plt



# INITIALISATION

filename = os.path.join('foo', 'bar.jpg')

img0 = cv2.imread(filename) # original image

gray = cv2.cvtColor(img0, cv2.COLOR_BGR2GRAY) # convert to grayscale

sift = cv2.xfeatures2d.SIFT_create() # initialize SIFT 

f, (ax1, ax2) = plt.subplots(1, 2) # create subplots



# DETECT AND DRAW KEYPOINTS

# sift.detect() returns a list of keypoints

# keypoint is a standard class of opencv (not just SIFT-related)

kp = sift.detect(gray,None) # calculates SIFT points

img1=cv2.drawKeypoints(gray,kp, None) # mae new image with keypoints drawn

ax1.imshow(img1) # plot 



# RETREIVE KEYPOINTS COORDINATES AND DRAW MANUALLY

# Reade these and make numpy array

pts = np.asarray([[p.pt[0], p.pt[1]] for p in kp])

cols = pts[:,0]

rows = pts[:,1]

ax2.imshow(cv2.cvtColor(img0, cv2.COLOR_BGR2RGB))

ax2.scatter(cols, rows)



plt.show()

edited Nov 2 '18 at 12:58

answered Nov 2 '18 at 10:40

quickbug

1,65931117

add a comment |

Here is my take (runable code):

import cv2, os

import numpy as np

import matplotlib.pyplot as plt



# INITIALISATION

filename = os.path.join('foo', 'bar.jpg')

img0 = cv2.imread(filename) # original image

gray = cv2.cvtColor(img0, cv2.COLOR_BGR2GRAY) # convert to grayscale

sift = cv2.xfeatures2d.SIFT_create() # initialize SIFT 

f, (ax1, ax2) = plt.subplots(1, 2) # create subplots



# DETECT AND DRAW KEYPOINTS

# sift.detect() returns a list of keypoints

# keypoint is a standard class of opencv (not just SIFT-related)

kp = sift.detect(gray,None) # calculates SIFT points

img1=cv2.drawKeypoints(gray,kp, None) # mae new image with keypoints drawn

ax1.imshow(img1) # plot 



# RETREIVE KEYPOINTS COORDINATES AND DRAW MANUALLY

# Reade these and make numpy array

pts = np.asarray([[p.pt[0], p.pt[1]] for p in kp])

cols = pts[:,0]

rows = pts[:,1]

ax2.imshow(cv2.cvtColor(img0, cv2.COLOR_BGR2RGB))

ax2.scatter(cols, rows)



plt.show()

edited Nov 2 '18 at 12:58

answered Nov 2 '18 at 10:40

quickbug

1,65931117

Here is my take (runable code):

import cv2, os

import numpy as np

import matplotlib.pyplot as plt



# INITIALISATION

filename = os.path.join('foo', 'bar.jpg')

img0 = cv2.imread(filename) # original image

gray = cv2.cvtColor(img0, cv2.COLOR_BGR2GRAY) # convert to grayscale

sift = cv2.xfeatures2d.SIFT_create() # initialize SIFT 

f, (ax1, ax2) = plt.subplots(1, 2) # create subplots



# DETECT AND DRAW KEYPOINTS

# sift.detect() returns a list of keypoints

# keypoint is a standard class of opencv (not just SIFT-related)

kp = sift.detect(gray,None) # calculates SIFT points

img1=cv2.drawKeypoints(gray,kp, None) # mae new image with keypoints drawn

ax1.imshow(img1) # plot 



# RETREIVE KEYPOINTS COORDINATES AND DRAW MANUALLY

# Reade these and make numpy array

pts = np.asarray([[p.pt[0], p.pt[1]] for p in kp])

cols = pts[:,0]

rows = pts[:,1]

ax2.imshow(cv2.cvtColor(img0, cv2.COLOR_BGR2RGB))

ax2.scatter(cols, rows)



plt.show()

edited Nov 2 '18 at 12:58

answered Nov 2 '18 at 10:40

quickbug

1,65931117

edited Nov 2 '18 at 12:58

answered Nov 2 '18 at 10:40

quickbug

1,65931117

answered Nov 2 '18 at 10:40

quickbug

1,65931117

answered Nov 2 '18 at 10:40

quickbug

1,65931117

add a comment |

I solved your problem like this.

kp,des = surf.detectAndCompute(img,None) 

pts = [p.pt for p in kp]

Now you get a list of x,y co-ordinates for all keypoints in your image.

edited Oct 6 '17 at 9:06

Shaido

12.6k122541

answered Oct 6 '17 at 8:49

Alexander Hunt

add a comment |

I solved your problem like this.

kp,des = surf.detectAndCompute(img,None) 

pts = [p.pt for p in kp]

Now you get a list of x,y co-ordinates for all keypoints in your image.

edited Oct 6 '17 at 9:06

Shaido

12.6k122541

answered Oct 6 '17 at 8:49

Alexander Hunt

add a comment |

I solved your problem like this.

kp,des = surf.detectAndCompute(img,None) 

pts = [p.pt for p in kp]

Now you get a list of x,y co-ordinates for all keypoints in your image.

edited Oct 6 '17 at 9:06

Shaido

12.6k122541

answered Oct 6 '17 at 8:49

Alexander Hunt

I solved your problem like this.

kp,des = surf.detectAndCompute(img,None) 

pts = [p.pt for p in kp]

Now you get a list of x,y co-ordinates for all keypoints in your image.

edited Oct 6 '17 at 9:06

Shaido

12.6k122541

answered Oct 6 '17 at 8:49

Alexander Hunt

edited Oct 6 '17 at 9:06

Shaido

12.6k122541

edited Oct 6 '17 at 9:06

Shaido

12.6k122541

edited Oct 6 '17 at 9:06

Shaido

12.6k122541

answered Oct 6 '17 at 8:49

Alexander Hunt

answered Oct 6 '17 at 8:49

Alexander Hunt

answered Oct 6 '17 at 8:49

Alexander Hunt

add a comment |

draft saved

draft discarded

Thanks for contributing an answer to Stack Overflow!

Please be sure to answer the question. Provide details and share your research!

But avoid …

Asking for help, clarification, or responding to other answers.

Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Name

Required, but never shown

Name

Required, but never shown

This page is only for reference, If you need detailed information, please check here

搜尋此網誌

Agfdhyk

how to extract x,y coordinates from OpenCV “cv2.keypoint” object?

5 Answers
5

class KeyPoint

Your Answer

Post as a guest

5 Answers
5

5 Answers
5

class KeyPoint

class KeyPoint

class KeyPoint

class KeyPoint

Post as a guest

Popular posts from this blog

Guess what letter conforming each word

Port of Spain

Run scheduled task as local user group (not BUILTIN)

how to extract x,y coordinates from OpenCV “cv2.keypoint” object?

5 Answers 5

class KeyPoint

Your Answer

Sign up or log in

Post as a guest

Post as a guest

5 Answers 5

5 Answers 5

class KeyPoint

class KeyPoint

class KeyPoint

class KeyPoint

Sign up or log in

Post as a guest

Post as a guest

Sign up or log in

Post as a guest

Sign up or log in

Post as a guest

Sign up or log in

Post as a guest

Popular posts from this blog

Guess what letter conforming each word

Port of Spain

Run scheduled task as local user group (not BUILTIN)

5 Answers
5

5 Answers
5

5 Answers
5