I have made simple code which is performing a blue filter. It adds some value to R value and substract something from GB values in two for() loops. It works great on PC but on mobile the performance is really slow. You can see the stuttering on the screen below. Ofc. changing the size of capture image helps but it is not a solution I am looking. How can you improve the performance, what's the best way to do image proccesing on mobile ?

Code:

import ketai.camera.*;

PImage prev;
float threshold = 60;

color currentColor;
color lastColor;

float r1 = 0;
float g1 = 0;
float b1 = 0;

KetaiCamera cam;
void setup() {
  orientation(LANDSCAPE);
  imageMode(CENTER);
  cam = new KetaiCamera(this, 320, 240, 24);
  prev = createImage(320, 240, RGB);
  cam.start();
}

void onCameraPreviewEvent(){
  cam.read();
}

void draw() {
    image(prev, width/2, height/2);
    cam.loadPixels();
    prev.loadPixels();
    loadPixels();

    for (int y = 0; y < cam.height; y++ ) 
  {
    for (int x = 0; x < cam.width; x++ ) 
    {
      int loc = x + y * cam.width; 
      currentColor = cam.pixels[loc]; //current values, taken from cam
      lastColor = prev.pixels[loc];

      float r1 = red(currentColor);
      float g1 = green(currentColor);
      float b1 = blue(currentColor);

      //pixels[loc] = color(r1+30,g1-35,b1-35);
      //float r2 = red(lastColor);
      //float g2 = green(lastColor);
      //float b2 = blue(lastColor);

       prev.pixels[loc] = color(r1-40,g1-40,b1+40);
      //prev.pixels[loc] = lerpColor(lastColor, currentColor, 0.9);

    }
  }
    prev.updatePixels();
    //image(prev, width/2, height/2);
    updatePixels();
  }

A related script: http://codepen.io/72lions/pen/jPzLJX

// duotone script

color c1, c2;

void setup() {  
  size(800, 800, P2D);
  colorMode(HSB, 255);

  c1 = color(240, 14, 46);
  c2 = color(25, 37, 80);

  PImage pic=loadImage("<a href="http://jquery-custom-scrollbar.rocketmind.pl/images/lena.png" target="_blank" rel="nofollow">http://jquery-custom-scrollbar.rocketmind.pl/images/lena.png</a>;");

  image(duotone(pic, c1, c2), 0, 0);
}


PImage duotone(PImage img, color color1, color color2) {

  img.resize(width, 0);
  img.filter(GRAY);

  color gradient[] = new color[256];

  // Creates a gradient of 255 colors between color1 and color2
  for (int d=0; d < 255; d++) {    
    float ratio= float(d)*0.00392156862745;
    gradient[d]=lerpColor(color1,color2,ratio);
  }

  loadPixels();
  for (int y = 0; y < img.height; y++) {
    for (int x = 0; x < img.width; x++) {
      int loc = x + y*img.width;

      // get the brightness
      float br = brightness(img.pixels[loc]);

      // The luminosity from 0 to 255 --this is necessary?
      float luminosity = max(0, min(254, round((br * 254))));

      // Set the pixel to a gradient with the level of brightness
      img.pixels[loc] = gradient[int(br)];   

      //img.pixels[loc] = gradient[int(luminosity)];  // this won't work
    }
  }

  updatePixels();  
  return(img);
}

Conditions: 1. I should be able to do programming only in C / C++, I shouldn’t use any part of Java or Python programming (since timing matters a lot) 2. I don’t want to use OpenCV, Matlab or any other higher image processing softwares or tools (since requirement of my task is very simple)

Any leads on where to start or what sort of method to deploy would be great!

Unfortunately, I don't know the math behind this tools. Do you have any leads wich could help me? My goal is to turn a picture like this :

Into this :

Thanks for you help!

Exploring a Design Space for Patterns and Tilings

a periodical programming competition involving Image Processing, Machine Learning, Mathematics and Visual Arts (student contributions are welcome)

The goal of this periodical programming competition (with some price money) is the exploration of a special design space of patterning & tiling methods and to make selected points of this space (methods that generate interesting and aesthetic results) available for image editing so that contemporary and future artists, illustrators, comic artists, designers, ... can use them under an open source license (CC0 and the like).

The design space relevant for image editing is based on the idea that patterns and tiles can be generated by basic shapes (prototiles) together with a CRMT command list approach that repeatedly clone, rotate and mirror a prototile and translate it over a finite pattern plane. With this unified approach the centuries of mathematical and artistic knowledge about patters, tilings and ornaments will be usable in image editing for bitmap and vector images. By programming CRMT-image interpreter as standalone programs or Plug-ins in bitmap graphic programs (GIMP, Photoshop, ...) and vector graphic programs (Illustrator, Inkscape) very powerful artistic tools can be made that will be using a growing number of CRMT command lists to generate all sorts of patterns from input images.

The goal of the first competition is to reproduce known tilings from the Tiling Database (http://www.tilingsearch.org/). This should be done by a learning process because such processes should be the basis for exploration the design space and its extensions in further iterations of the competition. Technically the learning of a CRMT command list for a tiling is viewed as a 2D packing problem with the 2-objective function "gap -> 0 & overlap -> 0".

The competition is originated in the field of Evolutionary Art therefore the learning process should be preferably done with Evolutionary Computation (EC) methods like Genetic Programming but it is not restricted to this if the learning environment with all aspects and parameters are published under an open source license so that others can use it for further exploration.

A detailed description of this programming competition with more technical details, winning conditions, price money, and future directions can be found under: http://de.evo-art.org/index.php?title=Exploring_a_Design_Space_for_Patterns_and_Tilings_Competition_2015

Registration starts on 01.05.2015 and ends on 15.11.2016. Contributions can be made until 15.01.2016.

Comments and suggestions to all aspects of the competition project are appreciated and should be addressed to Dr. Günter Bachelier (guba at evo-art.org).

Please redistribute this Call for Participation in appropriate mailing lists, blogs, tweets, ... to address and attract as much as possible developer, scientists and students in Evolutionary Computation, Machine Learning, Image Processing and Editing, Mathematics, Media Art, ...

When I print out the values of the pixels I get values for the land cover types(which are ranging from 10 to 100) as well numbers ranging from 0 to 255. How do I know what byte refers to the land cover type and what byte refers to the color palette ? I need a Pixel interpretation of the GEOTIFF file.

If there is no way then my only solution is to write some code where it takes a screen shot and freezes it, and then I do left mouse button presses in pixel of interest and then console prints the co-ordinates as well as the color.

Can you please help me to resolve this problem from my coding?

import toxi.geom.*;
import toxi.geom.mesh.*;

import toxi.processing.*;

TriangleMesh mesh;
ToxiclibsSupport gfx;

void setup() {
  size(displayWidth, displayHeight,P3D);
  mesh=(TriangleMesh)new STLReader().loadBinary(sketchPath("check.stl"),STLReader.TRIANGLEMESH);
  gfx=new ToxiclibsSupport(this);
}

void draw() {
  background(51);
  translate(width/2,height/2,0);
  rotateX(mouseY*0.01);
  rotateY(mouseX*0.01);

  gfx.mesh(mesh,false,10);
}