Moving object detection is a technique used in
computer vision
Computer vision is an interdisciplinary scientific field that deals with how computers can gain high-level understanding from digital images or videos. From the perspective of engineering, it seeks to understand and automate tasks that the hum ...
and image processing. Multiple consecutive frames from a video are compared by various methods to determine if any moving object is detected.
Moving objects detection has been used for wide range of applications like video surveillance,
activity recognition
Activity recognition aims to recognize the actions and goals of one or more agents from a series of observations on the agents' actions and the environmental conditions. Since the 1980s, this research field has captured the attention of several c ...
, road condition monitoring, airport safety, monitoring of protection along marine border, etc.
Definition
Moving object detection is to recognize the physical movement of an object in a given place or region.
J. S. Kulchandani and K. J. Dangarwala, "Moving object detection: Review of recent research trends," 2015 International Conference on Pervasive Computing (ICPC), Pune, 2015, pp. 1-5.
doi: 10.1109/PERVASIVE.2015.7087138. By acting
image segmentation, segmentation among moving objects and stationary area or region,
Weiming Hu, Tieniu Tan, Liang Wang, and Steve Maybank, “A Survey on Visual Surveillance of Object Motion and Behaviors,” IEEE Trans. on Systems, Man, and Cybernetics—Part C: Applications and Reviews,vol. 34, no. 3, pp. 334-352, August 2004. the moving objects' motion can be tracked and thus analyzed later. To achieve this, consider a video is a structure built upon single frames, moving object detection is to find the foreground moving target(s), either in each video frame or only when the moving target shows the first appearance in the video.
Traditional methods
Among all the traditional moving object detection methods, we could categorize them into four major approaches:
Background subtraction, Frame differencing, Temporal Differencing, and
Optical Flow
Optical flow or optic flow is the pattern of apparent motion of objects, surfaces, and edges in a visual scene caused by the relative motion between an observer and a scene. Optical flow can also be defined as the distribution of apparent veloci ...
.
Frame differencing
Instead of using traditional approach, to use image subtraction operator by subtracting second and images afterwards, the frame differencing method makes comparisons between two successive frames to detect moving targets.
Jain, R. and H. Nagel, “On the Accumulative Difference Pictures for the Analysis of Real World Scene Sequences,” IEEE Tran. on Pattern Anal. Mach. Intell., pp. 206-221, 1979.
Temporal differencing
The temporal differencing method identifies the moving object by applying pixel-wise difference method with two or three consecutive frames.
See also
* object detection
Object detection is a computer technology related to computer vision and image processing that deals with detecting instances of semantic objects of a certain class (such as humans, buildings, or cars) in digital images and videos. Well-researched ...
* motion estimation
Motion estimation is the process of determining ''motion vectors'' that describe the transformation from one 2D image to another; usually from adjacent frames in a video sequence. It is an ill-posed problem as the motion is in three dimensions b ...
* video tracking
Video tracking is the process of locating a moving object (or multiple objects) over time using a camera. It has a variety of uses, some of which are: human-computer interaction, security and surveillance, video communication and compression, aug ...
References
Image processing
Motion in computer vision