System information (version)

• OpenCV => 4.3 or later
• Operating System / Platform => Windows 10 (64 Bit)
• Compiler => Python 3.8.7

Detailed description

In Houghcircles, I got different shape of the result in using the method HOUGH_GRADIENT and HOUGH_GRADIENT_ALT.

In HOUGH_GRADIENT, the result is like:

[[[ x1 y1 r1 ]
[ x2 y2 r2 ]
[ x3 y3 r3 ]]]

circles.shape = (1, 3, 3)

But in HOUGH_GRADIENT_ALT, the result is like:

[[[ x1 y1 r1 ]]
[[ x2 y2 r2 ]]
[[ x3 y3 r3 ]]]

circles.shape = (3, 1, 3)

I wonder if it is a bug or this is the new feature of HOUGH_GRADIENT_ALT

Steps to reproduce

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues,
  answers.opencv.org, Stack Overflow, etc and have not found solution
• I updated to latest OpenCV version and the issue is still there
• There is reproducer code and related data files: videos, images, onnx, etc