Java - resize JPG image (high quality)

package com.example;

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import java.awt.image.BufferedImage;

import java.io.IOException;

​

public class Program {

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    public static void main(String[] args) throws IOException {

        BufferedImage originalImage = JpegImageUtils.readImage("original-image.jpg");

        if (originalImage != null) {

            BufferedImage resizedImage = JpegImageUtils.resizeImage(originalImage, 300, 300);

            JpegImageUtils.writeImage(resizedImage, 0.75f, "resized-image.jpg");

        }

    }

}

package com.example;

​

import java.awt.Image;

import java.awt.Color;

import java.awt.Graphics;

import java.awt.image.BufferedImage;

import java.io.IOException;

import java.io.InputStream;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.OutputStream;

import java.util.Iterator;

import javax.imageio.IIOImage;

import javax.imageio.ImageIO;

import javax.imageio.ImageWriter;

import javax.imageio.ImageWriteParam;

import javax.imageio.plugins.jpeg.JPEGImageWriteParam;

import javax.imageio.spi.IIORegistry;

import javax.imageio.spi.ImageWriterSpi;

import javax.imageio.spi.ServiceRegistry;

import javax.imageio.stream.MemoryCacheImageOutputStream;

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public final class JpegImageUtils {

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    // constants

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    private static final ImageWriterSpi SPI;

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    // constructors

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    static {

        IIORegistry registry = IIORegistry.getDefaultInstance();

        ServiceRegistry.Filter filter = (Object object) -> {

            ImageWriterSpi spi = (ImageWriterSpi) object;

            for (String type : spi.getMIMETypes()) {

                if ("image/jpeg".equals(type)) {

                    return true;

                }

            }

            return false;

        };

        Iterator<ImageWriterSpi> iterator = registry.getServiceProviders(ImageWriterSpi.class, filter, true);

        if (!iterator.hasNext()) {

            throw new RuntimeException("JPEG image writer is not supported.");

        }

        SPI = iterator.next();

    }

​

    private JpegImageUtils() {

        // Nothing here ...

    }

​

    // helper methods

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    private static ImageWriteParam createParameter(float quality) {

        JPEGImageWriteParam parameter = new JPEGImageWriteParam(null);

        parameter.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);

        parameter.setCompressionQuality(quality);

        return parameter;

    }

​

    private static ImageWriter createWriter(OutputStream stream) throws IOException {

        ImageWriter writer = SPI.createWriterInstance();

        try {

            writer.setOutput(new MemoryCacheImageOutputStream(stream));

        } catch (Throwable ex) {

            writer.dispose();

        }

        return writer;

    }

​

    // public methods

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    // ------ readImage

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    public static BufferedImage readImage(String path) throws IOException {

        try (FileInputStream stream = new FileInputStream(path)) {

            return ImageIO.read(stream);

        }

    }

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    public static BufferedImage readImage(InputStream stream) throws IOException {

        return ImageIO.read(stream);

    }

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    // ------ writeImage

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    public static void writeImage(BufferedImage srcImage, float dstQuality, String dstPath) throws IOException {

        try (FileOutputStream dstStream = new FileOutputStream(dstPath)) {

            writeImage(srcImage, dstQuality, dstStream);

        }

    }

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    public static void writeImage(BufferedImage srcImage, float dstQuality, OutputStream dstStream) throws IOException {

        IIOImage image = new IIOImage(srcImage, null, null);

        ImageWriteParam parameter = createParameter(dstQuality);

        ImageWriter writer = createWriter(dstStream);

        try {

            writer.write(null, image, parameter);

        } finally {

            writer.dispose();

        }

    }

​

    // ------ resizeImage

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    public static BufferedImage resizeImage(BufferedImage srcImage, int dstWidth, int dstHeight) {

        return resizeImage(srcImage, dstWidth, dstHeight, Image.SCALE_AREA_AVERAGING);

    }

​

    public static BufferedImage resizeImage(BufferedImage srcImage, int dstWidth, int dstHeight, int dstHints) {

        BufferedImage image = new BufferedImage(dstWidth, dstHeight, BufferedImage.TYPE_INT_BGR);

        Graphics graphics = image.getGraphics();

        try {

            Image descriptor = srcImage.getScaledInstance(dstWidth, dstHeight, dstHints);

            graphics.drawImage(descriptor, 0, 0, Color.WHITE, null);

        } finally {

            graphics.dispose();

        }

        return image;

    }

}