Using opencv.detect() and using the face position to replace mouse position in an existing sketch

Processing Libraries
1

Here's the code i currently have, for some reason i keep getting back ArrayIndexOutOfBoundsException = 0; when in theory i thought replacing the faces[i].x in place of mouseX and faces[i].y in place of mouseY would make sense

Face Detect Squares

package ccpd.library;

int barWidth = 20;

int lastBar = -1;


float max_distance;


import gab.opencv.;

import processing.video.;

import java.awt.*;


Capture video;

OpenCV opencv;


void setup() {

size(640, 480);

video = new Capture(this, 640/2, 480/2);

opencv = new OpenCV(this, 640/2, 480/2);

opencv.loadCascade(OpenCV.CASCADE_FRONTALFACE);


video.start();

noStroke();

max_distance = dist(0, 0, width, height);

}


void draw() {

background(0);

scale(2);

opencv.loadImage(video);


image(video, 0, 0 );


noFill();

can remove square on face

stroke(0, 255, 0);

strokeWeight(3);

Rectangle[] faces = opencv.detect();

println(faces.length);


for (int i = 0; i < faces.length; i++) {

println(faces[i].x + “,” + faces[i].y);

rect(faces[i].x, faces[i].y, faces[i].width, faces[i].height);

}

//to fill the squares with diff colour

int whichBar = mouseX / barWidth*2;

if (whichBar != lastBar) {

int barX = whichBar * barWidth;

// fill(mouseY, height, height);

stroke(0, 255, 0);

strokeWeight(3);

fill(mouseY, 0, 255);


for (int i = 0; i <= width; i += 20) {
  for (int j = 0; j <= height; j += 20) {
    //float size = dist(mouseX, mouseY, i, j);
    //change from mouseX,mousyY to positions of the face?
    float size = dist(faces[i].x, faces[i].y, i, j);
    size = size/max_distance * 150;
    rect(i, j, size, size);
  }
}



}

}


void captureEvent(Capture c) {

c.read();

}

Just squares (working)

package ccpd.utilities;

int barWidth = 20;

int lastBar = -1;


float max_distance;


void setup() {

size(640, 360);

stroke(0, 255, 0);

strokeWeight(2);

max_distance = dist(0, 0, width, height);

// colorMode(HSB, height, height, height);

}


void draw() {

background(0);

//to fill the squares with diff colour

int whichBar = mouseY / barWidth*2;

if (whichBar != lastBar) {

int barX = whichBar * barWidth;

fill(mouseY, height, height);

fill(mouseY, 0, 255);

//the squares

for (int i = 0; i <= width; i += 20) {

for (int j = 0; j <= height; j += 20) {


    float size = dist(mouseX, mouseY, i, j);
    size = size/max_distance * 150;
    rect(i, j, size, size);
  }
}



}

}
2

this is the line that I thought would make this work! Am i doing it wrong?

3

Hi,

Welcome to the forum! :wink:

Remember that you can press Ctrl+T in the Processing code editor to auto format your code (specially for indentation).

Also be sure to correctly use the ``` ``` characters to format your entire code and have syntax highlighting so it’s easier to read.

I think your issue is that the line :

float size = dist(faces[i].x, faces[i].y, i, j);

Is in a loop where i goes from 0 to width :

for (int i = 0; i <= width; i += 20) {}

But if the faces array does not contains i + 1 elements, then you have an ArrayIndexOutOfBoundsException because you are trying to access an element at an index that is too high.

What you want is to loop over all the faces in the array regardless it’s length (like you did in the code) :

for (int i = 0; i < faces.length; i++) {
  // Do something with faces[i]
}

Hope it helps! :wink:

1 Like
4

Hi Joseph!! Sorry about that! I was worried that i didn’t format it right.

AH i see!! I understand now, I’ll give it a shot. I appreciate your help! Thank you :smiley:

1 Like