Computer vision brightness or colour tracking

Processing Libraries
1

while doing color tracking using the camera as a sensor is thr a way to get a continuous line as you move the tracker around
the way i am doing is using an ellipse to follow the tracker but am not getting a continuous line

Would be very obliged if somebody can suggest
thanks

1 Like
2

Sharing code will help you get better advice.

If your tracker is giving you x,y each frame, then create a px, py from the previous frame. Let’s say the tracker is jumping around at random, and we want a line.

void setup() {
  size(400,400);
  strokeWeight(3);
  frameRate(3);
}
void draw() {
  float x = random(width);
  float y = random(height);
  ellipse(x, y, 10, 10);
}

Save the previous point at the end of each frame. Now each frame draw a line between previous and current point.

float px;
float py;
void setup() {
  size(400,400);
  strokeWeight(3);
  frameRate(3);
}
void draw() {
  float x = random(width);
  float y = random(height);
  line(px, py, x, y);
  px = x;
  py = y;
}

For the mouse, this is actually why pmouseX and pmouseY are built into Processing.

3

Thank you so very much
The solution was so simple and the very idea depended on the flow of the program in the loop
I think I got clarity of something which I often overlooked.
Is thr some tutorial (with detailed discussion) that deals with these basics in a very thorough manner more so as my knowledge of java is pretty limited on which processing is built .

1 Like
4

Perhaps try:

  1. the pmouseX reference page https://processing.org/reference/pmouseX.html
  2. the continuous lines example https://processing.org/examples/continuouslines.html and pattern example https://processing.org/examples/pattern.html
  3. the interactivity tutorial https://processing.org/tutorials/interactivity/

These assume pmousex is implemented – but, as you’ve seen, implementing a previous value is just saving it at the end of the loop. You can do something similar with previous time, previous color, previous click, et cetera.