# Threading on image processing
**URL:** https://discourse.processing.org/t/threading-on-image-processing/8439
**Category:** Libraries
**Created:** [February 16, 2019, 6:32am UTC](https://discourse.processing.org/t/threading-on-image-processing/8439 "2019-02-16T06:32:14Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@doni](https://discourse.processing.org/u/doni)
#### Post date: [February 16, 2019, 6:32am UTC](https://discourse.processing.org/t/threading-on-image-processing/8439/1 "2019-02-16T06:32:14Z")
hi i try to add another thread to improve fps or might be rendering process but my code do not succed
```auto
import processing.video.*;
Capture video;
void setup() {
size(640, 480);
// Uses the default video input, see the reference if this causes an error
video = new Capture(this, width, height);ot
video.start();
noStroke();
smooth();
}
void draw() {
if (video.available()) {
video.read();
image(video, 0, 0, width, height); // Draw the webcam video onto the screen
int brightestX = 0; // X-coordinate of the brightest video pixel
int brightestY = 0; // Y-coordinate of the brightest video pixel
float brightestValue = 0; // Brightness of the brightest video pixel
// Search for the brightest pixel: For each row of pixels in the video image and
// for each pixel in the yth row, compute each pixel's index in the video
video.loadPixels();
int index = 0;
for (int y = 0; y < video.height; y++) {
for (int x = 0; x < video.width; x++) {
// Get the color stored in the pixel
int pixelValue = video.pixels[index];
// Determine the brightness of the pixel
float pixelBrightness = brightness(pixelValue);
// If that value is brighter than any previous, then store the
// brightness of that pixel, as well as its (x,y) location
if (pixelBrightness > brightestValue) {
brightestValue = pixelBrightness;
brightestY = y;
brightestX = x;
}
index++;
}
}
thread("elipse");
}
}
void elipse (){
// Draw a large, yellow circle at the brightest pixel
fill(255, 204, 0, 128);
ellipse(brightestX, brightestY, 200, 200);
}
```
---
### Author:  [@neilcsmith](https://discourse.processing.org/u/neilcsmith)
#### Post date: [February 16, 2019, 10:04am UTC](https://discourse.processing.org/t/threading-on-image-processing/8439/2 "2019-02-16T10:04:59Z")
You cannot use thread to draw things. And you shouldn’t set off a thread every frame. Even if this worked it would decrease framerate not increase it.
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### Author:  [@jeremydouglass](https://discourse.processing.org/u/jeremydouglass)
#### Post date: [February 20, 2019, 6:45pm UTC](https://discourse.processing.org/t/threading-on-image-processing/8439/3 "2019-02-20T18:45:30Z")
> [@neilcsmith](#):
>
> You cannot use thread to draw things.
@doni – for more on _why_, read the reference page for `thread()`:
> You cannot draw to the screen from a function called by **thread()**. Because it runs independently, the code will not be synchronized to the animation thread, causing strange or at least inconsistent results.
> [thread() / Reference / Processing.org](https://processing.org/reference/thread_.html)
---
### Author:  [@doni](https://discourse.processing.org/u/doni)
#### Post date: [March 14, 2019, 12:45pm UTC](https://discourse.processing.org/t/threading-on-image-processing/8439/4 "2019-03-14T12:45:20Z")
@neilcsmith @jeremydouglass. what part of my code you suggest me to run on a thread. thank you