computer science

VIRAT

VIRAT is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand VIRAT rather than just read about it. In short: The Video and Image Retrieval and Analysis Tool (VIRAT) program is a video surveillance project funded by the Information Processing Technology Office of the Defense Advanced Research Projects Agency (DARPA). The purpose of the program was to create a database that could store large quantities of video, and make it easily searchable by intelligence agents to find "video content of interest" (e.g. "find all of the fo…

Key takeaways

VIRAT belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect VIRAT to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of VIRAT from memory before moving on to harder problems.

Reference excerpt

The Video and Image Retrieval and Analysis Tool (VIRAT) program is a video surveillance project funded by the Information Processing Technology Office of the Defense Advanced Research Projects Agency (DARPA). The purpose of the program was to create a database that could store large quantities of video, and make it easily searchable by intelligence agents to find "video content of interest" (e.g. "find all of the footage where three or more people are standing together in a group") -- this is known as "content-based searching". The other primary purpose was to create software that could provide "alerts" to intelligence operatives during live operations (e.g. "a person just entered the building"). The focus of VIRAT is primarily on footage from UAVs such as the MQ-1 Predator. As of the writing of the project solicitation in March 2008, most analysis of drone footage is done in a very labor-intensive manner by humans, who have to do manual "fast-forwarding" searches through video, or perform search queries of metadata or annotations added to videos earlier. The goal of VIRAT is to change all of this and have a large portion of the burden taken off of humans, and automating the analysis of surveillance video. VIRAT will focus heavily on developing means to be able to search through databases containing thousands of hours of video, looking for footage where certain types of activities took place, such as:

Single person: Digging, loitering, picking up, throwing, exploding/burning, carrying, shooting, launching, walking, limping, running, kicking, smoking, gesturing Person-to-person: Following, meeting, gathering, moving as a group, dispersing, shaking hands, kissing, exchanging objects, kicking, carrying an object together Person-to-vehicle: Driving, getting-in (out), loading (unloading), opening (closing) trunk, crawling under car, breaking window, shooting/launching, exploding/burning, dropping off, picking up Person-to-facility: Entering (exiting), standing, waiting at checkpoint, evading checkpoint, climbing atop, passing through gate, dropping off Vehicle: Accelerating (decelerating), turning, stopping, overtaking/passing, exploding/burning, discharging, shooting, moving together, forming into convoys, maintaining distance Other: VIP activities (convoy, parade, receiving line, troop formation, speaking to crowds), riding/leading animal, bicycling There are already highly developed object detection systems (e.g. programs that can determine whether an object in video footage is a "car" or a "person wearing a backpack"). VIRAT will utilize what is currently available for object detection. It is not within the scope of VIRAT to fund research in object detection, unless it is somehow related to identifying certain types of activities, like those mentioned above. The DARPA program manager for the VIRAT project is Dr. Mita Desai.

See also Biometrics Human identification at a distance Information Processing Technology Office MALINTENT Cameras

References

External links DARPA solicitations Listing of VIRAT team members FBO contracting awards and solicitations

Illustrations

Worked examples

Example 1 — a first encounter with VIRAT

Start with the simplest possible case. Write down what VIRAT claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to VIRAT before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about VIRAT ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of VIRAT

In research: VIRAT appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses VIRAT in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: VIRAT is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer vision software, Surveillance, so understanding it makes those chapters shorter.
In everyday life: Look for VIRAT outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study VIRAT in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what VIRAT means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain VIRAT out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is VIRAT in simple terms?

Why does VIRAT matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study VIRAT?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on VIRAT.