For Background Subtraction, the value nShadowDetection can't be set (Bug #3623)

Added by Ben Jones almost 11 years ago. Updated almost 11 years ago.

Status:Cancelled Start date:2014-03-26
Priority:Normal Due date:
Assignee:- % Done:

100%
Category:imgproc, video
Target version:- Estimated time:1.00 hour
Affected version:branch 'master' (3.0-dev) Operating System:Windows
Difficulty:Easy HW Platform:x86
Pull request:https://github.com/Itseez/opencv/pull/2681

Description

When you have an instance of the MOG2 background subtractor

cv::BackgroundSubtractorMOG2 mybacksub;

you can set all values, except

mybacksub.set("nShadowDetection", 120);

where an error occurs.

I think the error is likely to be in "bgfg_gaussmix2.cpp", line 782

Associated revisions

Revision f3439de4
Added by Vadim Pisarevsky about 10 years ago

Merge pull request #3623 from Trundle:fix_android_link

History

#1
Updated by Ben Jones almost 11 years ago

you can set all values, except

mybacksub.set("nShadowDetection", 120);

this means that all other parameters can be set (e.g. "fTau"). Setting "nShadowDetection" crashed for all values (not just 120).

#2
Updated by Sergei Nosov almost 11 years ago

Hi!

Thx for reporting! Could you, please, consider submitting a pull request to our repo on GitHub (https://github.com/Itseez/opencv) with a proposed fix?

  • Status changed from New to Open

#3
Updated by Sergei Nosov almost 11 years ago

  • Category set to imgproc, video

#4
Updated by Artur Wieczorek almost 11 years ago

Though BackgroundSubtractorMOG2 (and BackgroundSubtractorMOG) inherits from Algorithm class but interface to set/get parameters is not currently implemented.
In the pull request https://github.com/Itseez/opencv/pull/2681 there is submitted a patch implementing missing interface.

  • % Done changed from 0 to 100

#5
Updated by Andrew Senin almost 11 years ago

  • Pull request set to https://github.com/Itseez/opencv/pull/2681

#6
Updated by Vladislav Vinogradov almost 11 years ago

In 3.0 old get/set API with string parameter are replaced with separate get/set function for each parameter:

// old
bg->set("nShadowDetection", 0);
int n = bgs->getInt("nShadowDetection");

// new
bg->setShadowValue(0);
int n = bg->getShadowValue();

The old approach was declared obsolete. In 2.4 old API is used and it works.

I am cancelling the issue, please reopen if you disagree.

  • Status changed from Open to Cancelled
  • Affected version changed from 2.4.8 (latest release) to branch 'master' (3.0-dev)

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