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Change in pixel values indicates motion

A simple method of subtracting one movie frame from another will provide information about which parts of the scene have changed (generally due to motion). This method was performed on each frame of the movie, with consecutive frames being subtracted from each other.

Frame subtraction

First, the scene is converted to an array of pixel values. These pixel values are the averaged Red, Green, and Blue (RGB) values for each pixel. The pixel values of the previous frame are then subtracted from the current frame’s pixel values, and the absolute value of the values is taken. The result is an array of values that represent how much each pixel has changed between the two frames, with higher values representing more change. The amount of change in a region of pixels can be interpreted as the amount of motion that is taking place in that region. These data can then be used to determine where in the scene the most motion is taking place.

Illustrative example

The images below show the results of subtracting two frames from Punch Drunk Love. Note that these are NOT consecutive frames, as the changes between consecutive frames can be very small. The frames presented below were chosen to clearly illustrate the results of frame subtraction. In the “difference” frame, higher values (more change) are represented by white.

Figure 1: the current frame

Figure 1: the previous frame (not consecutive frames)

Figure 3: the “difference” frame

White regions indicate more change in pixel values. Very little change has occurred in much of the scene. Only the movement of the main character has resulted in a large amount of change in pixel values. Note that in this scene, the motion is taking place not in the center of the frame, but slightly offset to the left.

Questions & Answers

what is variations in raman spectra for nanomaterials
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I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
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Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
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Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
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what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
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Adin
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Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
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nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how did you get the value of 2000N.What calculations are needed to arrive at it
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Source:  OpenStax, Adaptive region of interest for video. OpenStax CNX. Dec 14, 2010 Download for free at http://cnx.org/content/col11256/1.1
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