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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

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
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.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
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
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
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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