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Implementation of the algorithm

The algorithm is implemented by the code in a conventional for loop, which begins in Listing 4 .

Listing 4 . Beginning of the for loop.
for(int cnt = 0;cnt<pixels.length;cnt++){ pixel = pixels[cnt];green = pixel.getGreen();blue = pixel.getBlue();

The loop iterates through the array of Pixel data, modifying the colors in one pixel during each iteration.

The length property of the array object

Every array object in Java contains a length property that contains the number of elements in the array. The value of this property is used in theconditional clause in the for loop in Listing 4 to establish when the end of the array has been reached in order to terminate the loop.

Get reference to the next Pixel object

The first statement inside the for loop in Listing 4 gets a reference to a Pixel object from the next array element. That reference is stored in the local variable of type Pixel named pixel that was declared in Listing 3 .

Get the red and green color values for the current pixel

Having gotten a reference to the Pixel object, the next statement calls the getGreen method on that reference to get and save the value of the green color component in the current pixel.

Similarly, the statement following that one gets and saves the value of the blue color component in the current pixel.

Both values are returned as type int , and can range in value from 0 up to and including 255.

Objective is to scale the green and blue color values

Recall that the objective is to scale the green and blue color values on a column by column basis, going from left to right across the image shown in Figure 1 in order to produce the output image shown in Figure 2 .

Organization of the pixel data

The pixel data is stored in the array on a row by row basis. In other words, the first width elements contain references to pixels in the first row of pixels going from left to right across the screen. The next width elements contain references to pixels in the second row of pixels, etc.

Compute the column number and scale factors

Listing 5 uses the modulus operator to compute the column number for each Pixel object.

Listing 5 . Compute the column number and scale factors.
//Compute the column number and use it to compute // the scale factor.int col = cnt%width;greenScale = (double)(width - col)/width; blueScale = (double)(col)/width;

An exercise for the student

Knowing the column number in which the pixel is located, the next step is to compute the green and blue scale factors necessary to satisfy the algorithm.

I will leave it as an exercise for the student to think about how the expressions contained in the last two statements in Listing 5 cause the two scale factors to vary linearly from left to right across the image in accordance with the requirements of the algorithm. (Think about the equation of a straight line from your high school math classes.)

Apply the scale factors

The Pixel class contains methods named setRed , setGreen , and setBlue that can be called to set the color values for the pixel represented by a Pixel object.

Questions & Answers

Do somebody tell me a best nano engineering book for beginners?
s. Reply
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Devang Reply
are you nano engineer ?
s.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
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SUYASH Reply
for screen printed electrodes ?
SUYASH
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s. Reply
of graphene you mean?
Ebrahim
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Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
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what's the easiest and fastest way to the synthesize AgNP?
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Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
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Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
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what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
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not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
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I'm interested in Nanotube
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this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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