Change pixel's color if in condition

leota

Hi there, I'm loading an image into a processing sketch and I would like to change all the black pixels to white. Here's my code, but changing are not having effect, i'm probably doing a wrong use of the set() method.

PImage img; 

void setup() {
  size(800,800);

  img = loadImage("texture.jpg");
}


void draw() {
  loadPixels();
  img.loadPixels();
  img.resize(800,800);
  //loop through every pixel
  for (int x = 1; x < img.width; x++) {
  for (int y = 0; y < img.height; y++ ) {

    // Calculate the 1D pixel location
    int loc = x + y*img.width;

    // Get the R,G,B values from image
    float r = red   (img.pixels[loc]);
    float g = green (img.pixels[loc]);
    float b = blue  (img.pixels[loc]);

    color white = color(255);

    if (r < 5) {
      set(x,y, white);
    } 

    color c = color(r,g,b);
    pixels[loc] = c;
  }
}
updatePixels();
}

Chrisir

line 29

img.set(x,y, white);

Chrisir

line 13 should be in setup()

Chrisir

line 15

  for (int x = 1;

should be

  for (int x = 0;

Chrisir

line 32+33 delete

you need to display img

using image (img,0,0);

Chrisir

line 36 img.updatePixels();

Chrisir

you have to decide: either you manipulate the image or the screen.

Better manipulate the image. Then you need to draw it each time. And also you need to have img. before operations like set, get, pixels, updatePixels....

Chrisir

maybe look at brightness... for line 28

leota

Thanks Chrisir, I've folollowed your suggestions but I'm getting this error: It looks like you're mixing "active" and "static" modes.

leota

By the way, I want to replace pixel color and then display the results, I don't want to change brightness.

leota

Sorry it actually works putting "image(img,0,0);" right after updatePixels(). Thanks for your help

Chrisir

you wrote

I don't want to change brightness

yes, I was just referring to the if in line 28

so it's only detection of the property of the pixel (black?) and not changing it

Chrisir

Glad you got it working!

yy2

hi, may i know what library that you have added for loading the pixel?

leota

No need to add any library, just use PImage Class