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Filtering

Overview

Although we have more contrast between our cell borders and the background, there is still a lot of noise which will need to be annihilated before edge detection can be successful. Ideally, we want to only preserve pixels which constitute a cell border and map all other pixels to a zero intensity.

Conversion to gray scale

Filtering is more easily done on a grayscale image than on a colormap image. This is due to the fact that grayscale images are intensity images with each pixel reflecting a particular intensity, rather than a combination of three colors (red, green and blue). With a grayscale image, filters such as mean and mode filters can be more appropriately applied.

Mean filtering

The first step in getting rid of unwanted pixels is to apply a mean filter. This filter will take a specified neighborhood around each pixel and set each pixel to the mean of its neighborhood. This is done with Matlab’s sliding neighborhood operation which will go through each pixel, taking its neighborhood pixels as inputs into a specified function and set each pixel as the output of the function.

In our case, the function we want to apply will take the neighboring pixels and output the mean. This mean represents the average intensity of its neighboring pixels. Thus, a lone intense (lit) pixel way out in the boondocks will be set to zero since there are no other high-intensity pixels nearby. This will effectively eliminate lone high-intensity pixels and thus decrease noise.

Following mean filtering, the image was converted to black and white. This was done by specifying a threshold intensity and setting all pixels above the threshold to 1 (white) and all pixels below to 0 (black). Why must this be done? Well, you’ll just have to read on to see… Figure 1 shows our final result in this step after converting to black and white.

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
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
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
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
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
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
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
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
Smarajit Reply
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Source:  OpenStax, Detection of cell boundaries in optical fiber probe images. OpenStax CNX. Jan 20, 2008 Download for free at http://cnx.org/content/col10501/1.2
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