Create an gaussian blur filter - Java 2D Graphics

Java examples for 2D Graphics:BufferedImage Blur

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Description

Create an gaussian blur filter

Demo Code


//package com.java2s;

import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;

public class Main {
    /**/*from  ww  w .j a v  a  2 s .c o  m*/
     * Create an gaussian blur filter
     *
     * @param radius     radius of the filter
     * @param horizontal whether it is horizontal blur
     * @return ConvolveOp  filter
     */
    public static ConvolveOp getGaussianBlurFilter(int radius,
            boolean horizontal) {
        if (radius < 1) {
            throw new IllegalArgumentException("Radius must be >= 1");
        }
        int size = radius * 2 + 1;
        float[] data = new float[size];
        float sigma = radius / 3.0f;
        float twoSigmaSquare = 2.0f * sigma * sigma;
        float sigmaRoot = (float) Math.sqrt(twoSigmaSquare * Math.PI);
        float total = 0.0f;
        for (int i = -radius; i <= radius; i++) {
            float distance = i * i;
            int index = i + radius;
            data[index] = (float) Math.exp(-distance / twoSigmaSquare)
                    / sigmaRoot;
            total += data[index];
        }
        for (int i = 0; i < data.length; i++) {
            data[i] /= total;
        }
        Kernel kernel;
        if (horizontal) {
            kernel = new Kernel(size, 1, data);
        } else {
            kernel = new Kernel(1, size, data);
        }
        return new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);
    }
}

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