hi everyone. guys helpme. i want to scan from 100 to 380 of my video.height

doni

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);
  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;
           pixelBrightness = color(256);
        }
        index++;
      }
    }
    // Draw a large, yellow circle at the brightest pixel
    fill(255, 204, 0, 128);
    ellipse(brightestX, brightestY, 50, 50);
     text("brightestX: " + brightestX, 20,20);
      text("brightestY: " + brightestY, 20,40);
      text("brightnesslevel: " + brightestValue, 20, 60);
  }
}

koogs

Edit post, highlight code, press Ctrl-o.

If we can't read it, we can't fix it.

doni

i want to scan from 100 to 380 of my video.height

Lord_of_the_Galaxy

Which part of

Edit post, highlight code, press Ctrl-o.

If we can't read it, we can't fix it.

Did you not understand?

doni

Lord_of_the_Galaxy i dont understand

Lord_of_the_Galaxy

Can you see that gear icon at the top right corner of your post? Press it to edit your post.
Then select your code as you would select any text on a computer. Press CTRL + O to indent your code. Then leave a line above and below the code and press save.

koogs

i want to scan from 100 to 380 of my video.height

well, line 25 currently does ALL of the video height

for (int y =0 ; y < video.height; y++) {

can you see how you would restrict it to just lines 100 to 380?

Lord_of_the_Galaxy

More clearly, it scans from 0 to video.height. You need from 100 to 380. See some sort of relation?

Lord_of_the_Galaxy

You're declaring y = 0 and limiting it with y < video.height. You need it to start at 100 and limit at 380. So you must replace two things here.

doni

what i mean is have screen size 640X480 but only scan the middle screen to increase FPS speed.

Lord_of_the_Galaxy

And what did we tell you to do? Did you try it?

doni

i have tried for (int y =100 ; y < video.height; y++) although my screen size 640X480 and the apps only scan 100 to 640. i also tried this but nothing for (int y =100 ; y < video.height > 380; y++).

kfrajer

@doni

You need to use a different index definition after you implement previous post's feedback. See the code below. Notice I have only pasted the relevant code, the for loops..

One a side note, this line is not proper: y < video.height > 380. To make things clear, I will write it this other way: (y < video.height) && (video.height > 380) . As you see, the comparison on the right is constant and not really useful.

Lastly, pixelBrightness = color(256); might not do what you want. Please check colorMode() in the reference. As default, a color definition will range from 0 to 255, inclusive. In you case, if you use 256, then you are probably looping around the full range. If you intend 256 to be white, you are going to get black. In other words, 255=white but 256=255+1 will be interpret as color(1) which is black.

Kf

for (int y =100; y < 380; y++) {
  for (int x = 0; x < video.width; x++) {
    index=y*width+x;  //###### ADDED
    // 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;
      pixelBrightness = color(256);
    }
    // // // index++;  //###### DISABLE
  }
}

Lord_of_the_Galaxy

Huh? Scan from 100 to 640? Are you using x for y and vice versa???

doni

thanks all you guys, especially @kfrajer. i got inspired by your idea and i tried some modification and ended at this code
for (int y = 100; (y < video.height && y < 380) ; y++)

Lord_of_the_Galaxy

No, no, no. Just use for (int y = 100; y < 380 ; y++)

koogs

i thought that too, but if the video is less than 380 high (is it?) you'll get errors.

Lord_of_the_Galaxy

The video is 640x480 as mentioned by the OP.

koogs

Where exactly does he say that?

Lord_of_the_Galaxy

In that case, I'd like to know what you thought he means by

have tried for (int y =100 ; y < video.height; y++) although my screen size 640X480 and the apps only scan 100 to 640. i also tried this but nothing for (int y =100 ; y < video.height > 380; y++).

Lord_of_the_Galaxy

(The OP's posts are indeed very confusing)

koogs

That's talking about screen size, obviously.

Don't assume the video is the same size.

Lord_of_the_Galaxy

@koogs int that case would you explain why he tells "scan"? Surely, he's scanning the video and not the screen?

Lord_of_the_Galaxy

(In fact, after displaying the video, resized, onto the screen, there's no need to even load the pixels of the video, he should be loading the pixels of the screen)