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53 lines
1.8 KiB
Plaintext
53 lines
1.8 KiB
Plaintext
/**
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* Edge Detection.
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*
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* A high-pass filter sharpens an image. This program analyzes every
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* pixel in an image in relation to the neighboring pixels to sharpen
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* the image. This example is currently not accurate in JavaScript mode.
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*/
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// The next line is needed if running in JavaScript Mode with Processing.js
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/* @pjs preload="moon.jpg"; */
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float[][] kernel = {{ -1, -1, -1},
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{ -1, 9, -1},
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{ -1, -1, -1}};
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PImage img;
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void setup() {
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size(640, 360);
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img = loadImage("moon.jpg"); // Load the original image
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noLoop();
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}
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void draw() {
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image(img, 0, 0); // Displays the image from point (0,0)
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img.loadPixels();
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// Create an opaque image of the same size as the original
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PImage edgeImg = createImage(img.width, img.height, RGB);
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// Loop through every pixel in the image.
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for (int y = 1; y < img.height-1; y++) { // Skip top and bottom edges
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for (int x = 1; x < img.width-1; x++) { // Skip left and right edges
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float sum = 0; // Kernel sum for this pixel
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for (int ky = -1; ky <= 1; ky++) {
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for (int kx = -1; kx <= 1; kx++) {
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// Calculate the adjacent pixel for this kernel point
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int pos = (y + ky)*img.width + (x + kx);
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// Image is grayscale, red/green/blue are identical
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float val = red(img.pixels[pos]);
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// Multiply adjacent pixels based on the kernel values
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sum += kernel[ky+1][kx+1] * val;
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}
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}
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// For this pixel in the new image, set the gray value
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// based on the sum from the kernel
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edgeImg.pixels[y*img.width + x] = color(sum, sum, sum);
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}
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}
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// State that there are changes to edgeImg.pixels[]
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edgeImg.updatePixels();
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image(edgeImg, width/2, 0); // Draw the new image
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}
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