This example is for Processing 3+. If you have a previous version, use the examples included with your software. If you see any errors or have suggestions, please let us know.

Blur.

A low-pass filter blurs an image. This program analyzes every pixel in an image and blends it with the neighboring pixels to blur the image.

```
float v = 1.0 / 9.0;
float[][] kernel = {{ v, v, v },
{ v, v, v },
{ v, v, v }};

PImage img;

void setup() {
size(640, 360);
noLoop();
}

void draw() {
image(img, 0, 0); // Displays the image from point (0,0)

// Create an opaque image of the same size as the original
PImage edgeImg = createImage(img.width, img.height, RGB);

// Loop through every pixel in the image
for (int y = 1; y < img.height-1; y++) {   // Skip top and bottom edges
for (int x = 1; x < img.width-1; x++) {  // Skip left and right edges
float sum = 0; // Kernel sum for this pixel
for (int ky = -1; ky <= 1; ky++) {
for (int kx = -1; kx <= 1; kx++) {
// Calculate the adjacent pixel for this kernel point
int pos = (y + ky)*img.width + (x + kx);
// Image is grayscale, red/green/blue are identical
float val = red(img.pixels[pos]);
// Multiply adjacent pixels based on the kernel values
sum += kernel[ky+1][kx+1] * val;
}
}
// For this pixel in the new image, set the gray value
// based on the sum from the kernel
edgeImg.pixels[y*img.width + x] = color(sum);
}
}
// State that there are changes to edgeImg.pixels[]
edgeImg.updatePixels();

image(edgeImg, width/2, 0); // Draw the new image
}

```