run_bg_esti — Estimate the background and return the foreground region.
run_bg_esti adapts the background image stored in the BgEsti data set using a Kalman filter on each pixel and returns a region of the foreground (detected moving objects).
For every pixel an estimation of its grayvalue is computed using the values of the current data set and its stored background image and the current image (PresentImage). By comparison to the threshold (fixed or adaptive, see create_bg_esti) the pixels are classified as either foreground or background.
The background estimation processes only single-channel images. Therefore the background has to be adapted separately for every channel.
The background estimation should be used on half- or even quarter-sized images. For this, the input images (and the initialization image!) has to be reduced using zoom_image_factor. The advantage is a shorter run-time on one hand and a low-band filtering on the other. The filtering eliminates high frequency noise and results in a more reliable estimation. As a result the threshold (see create_bg_esti) can be lowered. The foreground region returned by run_bg_esti then has to be enlarged again for further processing.
The passed image (PresentImage) must have the same type and size as the background image of the current data set (initialized with create_bg_esti).
Region of the detected foreground.
ID of the BgEsti data set.
* Read image for initialization: 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,ForegroundRegion1,BgEstiHandle) * Display the foreground region: dev_display (ForegroundRegion1) * Read the next image in sequence: read_image(Image2,'Image_2') * Estimate the background: run_bg_esti(Image2,ForegroundRegion2,BgEstiHandle) * Display the foreground region: dev_display (ForegroundRegion2) * etc.
run_bg_esti returns 2 (H_MSG_TRUE) if all parameters are correct.
set_bg_esti_params, create_bg_esti, update_bg_esti, give_bg_esti