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Listing 5. check for size problems.

//Display error message in place of image if the // image won't fit in the display window.if(img.width>width){ text("--Image too wide--",10,20);text("Image width: " + img.width,10,40); text("Display width: " + width,10,60);}else if(img.height>height){ text("--Image too tall--",10,20);text("Image height: " + img.height,10,40); text("Display height: " + height,10,60);}else{ //Copy pixel colors from the input image to the// display image.
Listing 5. Check for size problems.

Copy from input to output

If the image will fit in the display window, the code in Listing 6 is executed to begin the process of copying the pixel colors from the input image to the display image.

Listing 6. copy from input to output.

for(int cnt = 0;cnt<img.pixels.length;cnt++){ //Get and save RGB color values for current pixel.reD = red(img.pixels[cnt]);greeN = green(img.pixels[cnt]);bluE = blue(img.pixels[cnt]);//Normally some sort of image processing algorithm// would be implemented here.//Construct output pixel color color c = color(reD, greeN, bluE);
Listing 6. Copy from input to output.

An object of the PImage class

Although the syntax is unconventional, the call to the loadImage method in Listing 2 instantiates an object of the class named PImage and stores the object's reference in an instance variable named img . That object contains the pixel data extracted from the image file.

An object of the PImage class provides several methods that can be used to manipulate the image. In addition, an object of the PImage class contains fields for the width and height of the image, as well as an array named pixels[] that contains the values for every pixel in the image.

The arrays named pixels

The array containing the pixel data for the input image in this sketch can be accessed as img.pixels[] .

There is a similar pixel array that contains the pixel data for the output display window. That array can be accessed simply as pixels[] .

The data stored in the elements of these arrays is of the Processing primitive type color .

One-dimensional arrays

Although the pixels in an image can be thought of as a residing on a two-dimensional grid, the pixels are stored in these one-dimensional arrays row-by-row. In otherwords, the array element that is accessed as pixels[0] contains color data for the upper leftmost pixel in the image. The last element in the array contains color data for the bottom rightmost pixel in the image.

Extracting RGB color component values

The Pr0120a class inherits method named red , green , and blue .. These methods expect to receive a single parameter of type color , and return the value of the corresponding RGB component as type float . By default, the color component values range between 0.0 and 255.0.

The property named length and a for loop

Every array object in Java has a property named length whose value is equal to the number of elements in the array. This value is very usefulin the conditional clause of loops that are used to traverse an entire array.

Listing 6 shows the beginning of a for loop that

  • Extracts color component values from every pixel in the input image.
  • Uses those values to construct color values and insert them into the elements of the array containing the pixel data for the output display.

This process is complicated somewhat by the fact that the actual output image may be wider than the input image. This is indicated by the white space on the rightside of Image 1 . In other words, it is necessary to take this into account when computing the index of the output array element that isto receive the color from an input array element.

Store colors in the output array

The code that accomplishes that is shown in Listing 7 .

Listing 7. store colors in the output array.

if(width>= img.width){ if((cnt % img.width == 0)&&(cnt != 0)){ //Compensate for excess display width by// increasing the output counter. ctr += (width - img.width);}//end if //Store the pixel in the output pixel array// and increment the output counter. pixels[ctr]= c; ctr++;}//end if }//end for loopupdatePixels();//required}//end else
Listing 7. Store colors in the output array.

Questions & Answers

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
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
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.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
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
what is system testing
what is the application of nanotechnology?
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
anybody can imagine what will be happen after 100 years from now in nano tech world
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
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, The processing programming environment. OpenStax CNX. Feb 26, 2013 Download for free at http://cnx.org/content/col11492/1.5
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