When drawing circles a linetype of CV_AA does not cause the resulting drawing to be anti-aliased (Bug #4159)

Added by Dave Williams about 10 years ago. Updated about 10 years ago.

Status:Cancelled Start date:2015-01-29
Priority:Normal Due date:
Assignee:Vadim Pisarevsky % Done:

0%
Category:python bindings
Target version:-
Affected version:2.4.9 (latest release) Operating System:Mac OSX
Difficulty: HW Platform:x64
Pull request:

Description

To reproduce using Python: 

import numpy as np
import cv2
test_img = np.zeros((10,10))
print test_img
cv2.circle(test_img, (5,5), 2, 100, 2, cv2.cv.CV_AA)
print test_img

The result is a circle drawn with values of 100, but no anti-aliased 0-to-100 values, despite the line specification. Output copied below for reference:

[[ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]
 [ 0.  0.  0.  0.  0.  0.  0.  0.  0.  0.]]
[[   0.    0.    0.    0.    0.    0.    0.    0.    0.    0.]
 [   0.    0.    0.    0.    0.    0.    0.    0.    0.    0.]
 [   0.    0.    0.    0.  100.  100.  100.    0.    0.    0.]
 [   0.    0.    0.  100.  100.  100.  100.  100.    0.    0.]
 [   0.    0.  100.  100.  100.  100.  100.  100.  100.    0.]
 [   0.    0.  100.  100.  100.  100.  100.  100.  100.    0.]
 [   0.    0.  100.  100.  100.  100.  100.  100.  100.    0.]
 [   0.    0.    0.  100.  100.  100.  100.  100.    0.    0.]
 [   0.    0.    0.    0.  100.  100.  100.    0.    0.    0.]
 [   0.    0.    0.    0.    0.    0.    0.    0.    0.    0.]]

Associated revisions

Revision 40fcc9d1
Added by Alexander Alekhin over 9 years ago

Merge pull request #4159 from alalek:vector_processing

History

#1
Updated by Nisarg Thakkar about 10 years ago

This has been fixed in 2.4.10 and a pull request has been sent for 3.0.
https://github.com/Itseez/opencv/pull/3309

  • Status changed from New to Done
  • % Done changed from 0 to 100

#2
Updated by Nisarg Thakkar about 10 years ago

Sorry, that was a different bug

  • Status changed from Done to Open
  • % Done changed from 100 to 0

#3
Updated by Nisarg Thakkar about 10 years ago

You should change your code to :

test_img = np.zeros((10,10), np.uint8)

#4
Updated by Dave Williams about 10 years ago

Nisarg Thakkar wrote:

You should change your code to :
[...]

That fixes it, thanks!

Let me know if there is any way to infer this type of required type from the documentation. It seems like CvArr's have different restrictions on them depending on what function they are being passed to, restrictions that for the life of me I can't intuit from the docs.

  • Status changed from Open to Cancelled

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