Look at pixels[] and friends (loadPixels, etc.).

pixels[] seemed appropriate for a linear scan of the list of pixels...

Quoting the manual: "Getting the color of a single pixel with get(x, y) is easy, but not as fast as grabbing the data directly from pixels[]." and the JavaDoc: "This function is included primarily for beginners. It is quite slow because it has to check to see if the x, y that was provided is inside the bounds, and then has to check to see what image type it is. If you want things to be more efficient, access the pixels[] array directly."

Indeed, it adds 4 tests and a switch to each get. That's not much, and might not do a noticeable difference for a one time usage, but might do a difference for an algorithm reading each pixel several times (some filter) on each frame.

Hi all,
This is what i'm trying to do, but i can't achieve the result i need... any help?? thanks in advance..




Code:

int widthImg = 600;
int heightImg = 635;

size(1200,600, P3D);
//background(240);

//float fov = mouseX/float(width) * PI/2;
// float cameraX = width;
//float cameraZ = (height/2.0) / tan(fov / 2.0);

//perspective();
//perspective(fov, float(width)/float(height), cameraZ/10.0, cameraZ*10.0);
//ortho(-width/2, width/2, -height/2, height/2, -10, 10); 

   float fov = PI/3.0; 
    float cameraZ = (height/2.0) / tan(PI * fov / 360.0); 
    perspective(fov, float(width)/float(height), 
		    cameraZ/2.0, cameraZ*2.0); 

   


// X, Z, Y --> eye, center , etc...
//camera(0, 600, 0, 600, 0, -600, 0, 1, 0);

//rect(0,0, 100, 100);


//ortho(-width/2, width/2, -height/2, height/2, -10, 10); 

//strokeWeight(1);

// griglia set-up
//line(x1,y1,z1, x2,y2,z2);
// inverted X as X / Y as -Z / Z as Y

line(0, 0+600, 0, 0, 600, -9000); // y axis
line(100, 0+600, 0, 0, 600, -9000); // y axis
line(200, 0+600, 0, 0, 600, -9000); // y axis
line(300, 0+600, 0, 0, 600, -9000); // y axis
line(400, 0+600, 0, 0, 600, -9000); // y axis
line(500, 0+600, 0, 0, 600, -9000); // y axis
line(600, 0+600, 0, 0, 600, -9000); // y axis
line(700, 0+600, 0, 0, 600, -9000); // y axis
line(800, 0+600, 0, 0, 600, -9000); // y axis
// line (X, Z, Y);
line(0, 0+600, -200, 800, 0+600, -200); // x axis
line(0, 0+600, -400, 800, 0+600, -400); // x axis
line(0, 0+600, -600, 800, 0+600, -600); // x axis
line(0, 0+600, -800, 800, 0+600, -800); // x axis


PImage img = loadImage("mestreorto.jpg");

color fillColor = color(0,255,0);
color black = color(0,0,0);

colorMode(HSB, 360, 100, 100);

img.loadPixels();
for (int i = 0; i < (widthImg*heightImg); i++){
    color c = img.pixels[i];
   
    if (hue(c) >= 35 && hue(c) <= 150 && saturation(c) > 25 && brightness(c) > 15 && brightness(c) < 95){
	    img.pixels[i] = fillColor;
	    int riga = 0;
		if(i > 600){
		    riga = i/600;
		  }else{
		    riga = 0;
		  }
	    int colonna = 0;
		if(i > 100){
		    colonna = i-((i/600)*600);
		  }else{
		    colonna = i;
		  }
		  
		  //real coordinates
		  //translate(colonna, riga, hue(c));
		  
		  float x = colonna;
		  float y = riga;
		  float z = hue(c)/2;
		  
		  // point (x,z,y);
		  //stroke(fillColor);
		  //point (x, (z*-1.0)+600, (-1.0*y));
		  
		  println("colonna -> " + colonna + "// hue->" + hue(c) + "// riga->" + riga );
	    
    }else{
	img.pixels[i] = black;
    }
    
}

/*
PImage a = loadImage("mestreorto.jpg");
beginShape();
texture(a);
// X, Z, Y 
vertex(0, 600, 0, 0);
vertex(600, 600, 0, 0);
vertex(0, 600, 635, 635);
vertex(600, 600, 635, 635);
endShape();
*/

//img.updatePixels();
// image(img, 0, 0);