Moving object detection

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Moving object detection is a technique used in computer vision and image processing. Multiple consecutive frames from a video are compared by various methods to determine if any moving object is detected.

Contents

Moving objects detection has been used for wide range of applications like video surveillance, activity recognition, road condition monitoring, airport safety, monitoring of protection along marine border, etc. [1]

Definition

Moving object detection is to recognize the physical movement of an object in a given place or region. [2] By acting segmentation among moving objects and stationary area or region, [3] 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. [4]

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. [2]

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. [5]

Temporal differencing

The temporal differencing method identifies the moving object by applying pixel-wise difference method with two or three consecutive frames. [3]

See also

Related Research Articles

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Frame rate, most commonly expressed in frames per second or FPS, is typically the frequency (rate) at which consecutive images (frames) are captured or displayed. This definition applies to film and video cameras, computer animation, and motion capture systems. In these contexts, frame rate may be used interchangeably with frame frequency and refresh rate, which are expressed in hertz. Additionally, in the context of computer graphics performance, FPS is the rate at which a system, particularly a GPU, is able to generate frames, and refresh rate is the frequency at which a display shows completed frames. In electronic camera specifications frame rate refers to the maximum possible rate frames could be captured, but in practice, other settings may reduce the actual frequency to a lower number than the frame rate.

<span class="mw-page-title-main">Motion compensation</span> Video compression technique, used to efficiently predict and generate video frames

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<span class="mw-page-title-main">Image segmentation</span> Partitioning a digital image into segments

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<span class="mw-page-title-main">Motion estimation</span> Process used in video coding/compression

In computer vision and image processing, 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 happens in three dimensions (3D) but the images are a projection of the 3D scene onto a 2D plane. The motion vectors may relate to the whole image or specific parts, such as rectangular blocks, arbitrary shaped patches or even per pixel. The motion vectors may be represented by a translational model or many other models that can approximate the motion of a real video camera, such as rotation and translation in all three dimensions and zoom.

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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 computer science communities due to its strength in providing personalized support for many different applications and its connection to many different fields of study such as medicine, human-computer interaction, or sociology.

<span class="mw-page-title-main">Object detection</span> Computer technology related to computer vision and image processing

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 in digital images and videos. Well-researched domains of object detection include face detection and pedestrian detection. Object detection has applications in many areas of computer vision, including image retrieval and video surveillance.

<span class="mw-page-title-main">Pedestrian detection</span> Computer technology

Pedestrian detection is an essential and significant task in any intelligent video surveillance system, as it provides the fundamental information for semantic understanding of the video footages. It has an obvious extension to automotive applications due to the potential for improving safety systems. Many car manufacturers offer this as an ADAS option in 2017.

<span class="mw-page-title-main">Video synopsis</span>

Video synopsis is a method for automatically synthesizing a short, informative summary of a video. Unlike traditional video summarization, the synopsis is not just composed of frames from the original video. The algorithm detects, tracks and analyzes moving objects in a database of objects and activities. The final output is a new, short video clip in which objects and activities that originally occurred at different times are displayed simultaneously, so as to convey information in the shortest possible time. Video synopsis has specific applications in the field of video analytics and video surveillance where, despite technological advancements and increased growth in the deployment of CCTV cameras, viewing and analysis of recorded footage is still a costly labor-intensive and time-intensive task.

ViBe is a background subtraction algorithm which has been presented at the IEEE ICASSP 2009 conference and was refined in later publications. More precisely, it is a software module for extracting background information from moving images. It has been developed by Oliver Barnich and Marc Van Droogenbroeck of the Montefiore Institute, University of Liège, Belgium.

Foreground detection is one of the major tasks in the field of computer vision and image processing whose aim is to detect changes in image sequences. Background subtraction is any technique which allows an image's foreground to be extracted for further processing.

In computer vision, rigid motion segmentation is the process of separating regions, features, or trajectories from a video sequence into coherent subsets of space and time. These subsets correspond to independent rigidly moving objects in the scene. The goal of this segmentation is to differentiate and extract the meaningful rigid motion from the background and analyze it. Image segmentation techniques labels the pixels to be a part of pixels with certain characteristics at a particular time. Here, the pixels are segmented depending on its relative movement over a period of time i.e. the time of the video sequence.

<span class="mw-page-title-main">Saliency map</span> Type of image

In computer vision, a saliency map is an image that highlights either the region on which people's eyes focus first or the most relevant regions for machine learning models. The goal of a saliency map is to reflect the degree of importance of a pixel to the human visual system or an otherwise opaque ML model.

<span class="mw-page-title-main">Object co-segmentation</span> Type of image segmentation, jointly segmenting semantically similar objects in multiple images

In computer vision, object co-segmentation is a special case of image segmentation, which is defined as jointly segmenting semantically similar objects in multiple images or video frames.

<span class="mw-page-title-main">Event camera</span> Type of imaging sensor

An event camera, also known as a neuromorphic camera, silicon retina or dynamic vision sensor, is an imaging sensor that responds to local changes in brightness. Event cameras do not capture images using a shutter as conventional (frame) cameras do. Instead, each pixel inside an event camera operates independently and asynchronously, reporting changes in brightness as they occur, and staying silent otherwise.

<span class="mw-page-title-main">Video super-resolution</span> Generating high-resolution video frames from given low-resolution ones

Video super-resolution (VSR) is the process of generating high-resolution video frames from the given low-resolution video frames. Unlike single-image super-resolution (SISR), the main goal is not only to restore more fine details while saving coarse ones, but also to preserve motion consistency.

References

  1. Chaquet, Jose M.; Carmona, Enrique J.; Fernández-Caballero, Antonio (June 2013). "A survey of video datasets for human action and activity recognition". Computer Vision and Image Understanding. 117 (6): 633–659. doi:10.1016/j.cviu.2013.01.013. hdl: 10578/3697 .
  2. 1 2 , 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.
  3. 1 2 , 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.
  4. , Bahadir Karasulu and Serdar Korukoglu (2013). Performance Evaluation Software: Moving Object Detection and Tracking in Videos.
  5. , 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.