set_bg_esti

Herror ::set_bg_esti_params ( const HTuple &BgEstiHandle, const HTuple &Syspar1, const HTuple &Syspar2, const HTuple &GainMode, const HTuple &Gain1, const HTuple &Gain2, const HTuple &AdaptMode, const HTuple &MinDiff, const HTuple &StatNum, const HTuple &ConfidenceC, const HTuple &TimeC )

Change the parameters of the data set.

::set_bg_esti_params is used to change the parameters of the data set. The parameters passed by ::set_bg_esti_params are the same as in ::create_bg_esti (see there for an explanation).

The image format cannot be changed! To do this, a new data set with an initialization image of the appropriate format has to be created.

To exchange the background image completely, use ::update_bg_esti. The current image then has to be passed for both the input image and the update region.

Attention

If GainMode was set to 'frame', the run-time can be extremly long for large values of Gain1 or Gain2, because the values for the gains' table are determined by a simple binary search.

Parameters

`BgEstiHandle` (input_control)	bg_estimation `->` HTuple.long
ID of the BgEsti data set.

`Syspar1` (input_control)	real `->` HTuple.double
1. system matrix parameter.
Default value: 0.7
Suggested values: 0.65, 0.7, 0.75
Typical range of values: `0.05 <= Syspar1 <= 1.0`
Recommended increment: 0.05

`Syspar2` (input_control)	real `->` HTuple.double
2. system matrix parameter.
Default value: 0.7
Suggested values: 0.65, 0.7, 0.75
Typical range of values: `0.05 <= Syspar2 <= 1.0`
Recommended increment: 0.05

`GainMode` (input_control)	string `->` HTuple.char *
Gain type.
Default value: 'fixed'
List of values: 'fixed', 'frame'

`Gain1` (input_control)	real `->` HTuple.double
Kalman gain / foreground adaptation time.
Default value: 0.002
Suggested values: 10.0, 20.0, 50.0, 0.1, 0.05, 0.01, 0.005, 0.001
Restriction: `0.0 <= Gain1`

`Gain2` (input_control)	real `->` HTuple.double
Kalman gain / background adaptation time.
Default value: 0.02
Suggested values: 2.0, 4.0, 8.0, 0.5, 0.1, 0.05, 0.01
Restriction: `0.0 <= Gain2`

`AdaptMode` (input_control)	string `->` HTuple.char *
Threshold adaptation.
Default value: 'on'
List of values: 'on', 'off'

`MinDiff` (input_control)	real `->` HTuple.double
Foreground/background threshold.
Default value: 7.0
Suggested values: 3.0, 5.0, 7.0, 9.0, 11.0
Recommended increment: 0.2

`StatNum` (input_control)	integer `->` HTuple.long
Number of statistic data sets.
Default value: 10
Suggested values: 5, 10, 20, 30
Typical range of values: `1 <= StatNum`
Recommended increment: 5

`ConfidenceC` (input_control)	real `->` HTuple.double
Confidence constant.
Default value: 3.25
Suggested values: 4.30, 3.25, 2.82, 2.62
Recommended increment: 0.01
Restriction: `0.0 < ConfidenceC`

`TimeC` (input_control)	real `->` HTuple.double
Constant for decay time.
Default value: 15.0
Suggested values: 10.0, 15.0, 20.0
Recommended increment: 5.0
Restriction: `0.0 < TimeC`

Example

/* read Init-Image:*/
read_image(&InitImage,"Init_Image") ;
/* initialize BgEsti-Dataset with 
   fixed gains and threshold adaption: */
create_bg_esti(InitImage,0.7,0.7,"fixed",0.002,0.02,
               "on",7.0,10,3.25,15.0,&BgEstiHandle) ;
/* read the next image in sequence: */
read_image(&Image1,"Image_1") ;
/* estimate the Background: */
run_bg_esti(Image1,&Region1,BgEstiHandle) ;
/* display the foreground region: */
disp_region(Region1,WindowHandle) ; 
/* read the next image in sequence: */
read_image(&Image2,"Image_2") ;
/* estimate the Background: */
run_bg_esti(Image2,&Region2,BgEstiHandle) ;
/* display the foreground region: */
disp_region(Region2,WindowHandle) ;
/* etc. */
/* change parameter in dataset: */
set_bg_esti_params(BgEstiHandle,0.7,0.7,"fixed",
                   0.004,0.08,"on",9.0,10,3.25,20.0) ;
/* read the next image in sequence: */
read_image(&Image3,"Image_3") ;
/* estimate the Background: */
run_bg_esti(Image3,&Region3,BgEstiHandle) ;
/* display the foreground region: */
disp_region(Region3,WindowHandle) ; 
/* etc. */

Result

::set_bg_esti_params returns H_MSG_TRUE if all parameters are correct.

Possible Predecessors

::create_bg_esti

Possible Successors

::run_bg_esti

See also

::update_bg_esti

Module

Background estimation