set_bg_esti

set_bg_esti_params ( : : BgEstiHandle, Syspar1, Syspar2, GainMode, Gain1, Gain2, AdaptMode, MinDiff, StatNum, ConfidenceC, 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 `->` integer
ID of the BgEsti data set.

`Syspar1` (input_control)	real `->` real
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 `->` real
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 `->` string
Gain type.
Default value: 'fixed'
List of values: 'fixed', 'frame'

`Gain1` (input_control)	real `->` real
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 `->` real
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 `->` string
Threshold adaptation.
Default value: 'on'
List of values: 'on', 'off'

`MinDiff` (input_control)	real `->` real
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 `->` integer
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 `->` real
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 `->` real
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 2 (H_MSG_TRUE) if all parameters are correct.

Parallelization Information

set_bg_esti_params is reentrant and processed without parallelization.

Possible Predecessors

create_bg_esti

Possible Successors

run_bg_esti

See also

update_bg_esti

Module

Background estimation