Video ghost detection by outline
Video image ghost detection in a security/surveillance CCTV system for automated image analysis. At least one pass of a video frame produces a terrain map with video content-indicating parameters, by which are analyzed behavior of objects, e.g., people and vehicles, moving in a scene having a background and a foreground, while detecting “ghost” images of objects that were in an adaptive background of the scene but are moving, by measuring a horizontal smoothness and/or vertical smoothness by segmentation procedure by which an object outline is predicted. The examination of segmented background and foreground image portions is conducted by software process to determine existence of such outline as by edge detection or changes in texture. Probability of an image ghost in either the background or foreground, or both, is calculated.
1 . A method of video image ghost detection for use in a video surveillance system using real-time image analysis of video data wherein at least one pass of a video frame produces a terrain map containing parameters indicating content of background and foreground video images, said method comprising
(a) measuring one or more parameters in the terrain map for smoothness in segmentation to predict where an outline of an object is predicted,
(b) considering the magnitudes of differences in regions of predicted object outlines;
(c) determining from the magnitudes of differences in regions the probability of image ghosting therein in either background or foreground images or both.
2 . A method as set forth in claim 1 further comprising calculating from said magnitudes of differences the percentage of likelihood of a ghost in either background or foreground of the image.
3 . A method as set forth in claim 2 comprising quantifying said percentage for further use.
4 . A method as set forth in claim 1 wherein step (a) is carried out by comparing a horizontal or vertical smoothness parameter of the terrain map.
5 . A method as set forth in claim 4 wherein step (b) is carried out by system software examination of segmented image portions to determine existence of an object outline by edge detection or changes in texture.
6 . A method as set forth in claim 5 wherein step (b) is carried out in both background and foreground images and magnitudes of differences between background and foreground are compared to determine if an image ghost appears in either the background or foreground or both.
7 . A method as set forth in claim 6 , wherein steps (b) and (c) are carried out for each row of a target area within the background and foreground images, by software sequential steps.
8 . A method as set forth in claim 6 , wherein a predicted object outline on the left side is defined by the left-most segmented pixel, and wherein the left-most segmented pixel in both the foreground image and the background image is compared to its adjacent non-segmented pixel, and further wherein the same procedure is followed on the right side of the target and all rows from both sides of the target are compared.
9 . In a video system for automatically screening video cameras wherein software elements provide real-time image analysis of video data is performed, and wherein at least a single pass of a video frame produces a terrain map which contains parameters indicating the content of the video, a method of video image ghost detection comprising:
(a) measuring one or more parameters in the terrain map for smoothness in segmentation to predict where an outline of an object is predicted,
(b) considering the magnitudes of differences in regions of predicted object outlines;
(c) determining from the magnitudes of differences in regions the probability of image ghosting therein in either background or foreground images or both.
10 . A method as set forth in claim 9 further comprising calculating from said magnitudes of differences the percentage of likelihood of a ghost in either background or foreground of the image.
11 . A method as set forth in claim 10 comprising quantifying said percentage for further use in said system.
12 . A method as set forth in claim 9 wherein step (a) is carried out by comparing a horizontal or vertical smoothness parameter of the terrain map.
13 . A method as set forth in claim 12 wherein step (b) is carried out by system software examination of segmented image portions to determine existence of an object outline by edge detection or changes in texture.
14 . A method as set forth in claim 13 wherein step (b) is carried out in both background and foreground images and magnitudes of differences between background and foreground are compared to determine if an image ghost appears in either the background or foreground or both.
15 . A method as set forth in claim 14 , wherein steps (b) and (c) are carried out for each row of a target area within the background and foreground images, by software steps.
16 . A method as set forth in claim 15 , wherein a predicted object outline on the left side is defined by the left-most segmented pixel, and wherein the left-most segmented pixel in both the foreground image and the background image is compared to its adjacent non-segmented pixel, and further wherein the same procedure is followed on the right side of the target and all rows from both sides of the target are compared.
17 . A method of video image ghost detection for use in a video system using real-time image analysis of video data wherein a video frame is analyzed to provide a set of data containing parameters indicating content of background and foreground video images, said method comprising
(a) measuring one or more parameters to predict where an outline of an object is predicted,
(b) considering the magnitudes of differences in regions of predicted object outlines;
(c) determining from the magnitudes of differences in regions the probability of image ghosting therein in either background or foreground images or both.