JAVA-6503: Image compression in Java (#14081)

image-compressing/src/main/java/com/baeldung/image/compression/ImageCompressor.java

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+package com.baeldung.image.compression;
+
+
+import javax.imageio.ImageIO;
+import javax.imageio.ImageWriteParam;
+import javax.imageio.ImageWriter;
+import javax.imageio.stream.ImageOutputStream;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+import java.util.Iterator;
+
+
+public class ImageCompressor {
+
+    public static void compressImage(String inputPath, String outputPath) throws IOException {
+        File inputFile = new File(inputPath);
+        BufferedImage inputImage = ImageIO.read(inputFile);
+
+        Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("jpg");
+        ImageWriter writer = writers.next();
+
+        File outputFile = new File(outputPath);
+        ImageOutputStream outputStream = ImageIO.createImageOutputStream(outputFile);
+        writer.setOutput(outputStream);
+
+        ImageWriteParam params = writer.getDefaultWriteParam();
+        params.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
+        params.setCompressionQuality(0.5f);
+
+        writer.write(null, new javax.imageio.IIOImage(inputImage, null, null), params);
+
+        outputStream.close();
+        writer.dispose();
+    }
+}

image-compressing/src/main/java/com/baeldung/image/compression/ThumbnailsCompressor.java

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+package com.baeldung.image.compression;
+
+
+import net.coobird.thumbnailator.Thumbnails;
+
+import java.io.File;
+import java.io.IOException;
+
+public class ThumbnailsCompressor {
+
+    public static void compressImage(String inputPath, String outputPath) throws IOException {
+        File input = new File(inputPath);
+        File output = new File(outputPath);
+        Thumbnails.of(input)
+                .scale(1)
+                .outputQuality(0.5)
+                .toFile(output);
+    }
+}

image-compressing/src/test/java/com/baeldung/image/compression/ImageCompressorUnitTest.java

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+package com.baeldung.image.compression;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+
+class ImageCompressorUnitTest {
+    @Test
+    void testSecondFileIsSmaller() throws IOException {
+        String inputImagePath = ImageCompressorUnitTest.class.getClassLoader()
+                .getResource("input.jpg").getPath();
+        File inputImage = new File(inputImagePath);
+        long inputImageSize = inputImage.length();
+        String outputPath = inputImagePath + "compressed.jpg";
+        ImageCompressor.compressImage(inputImagePath, outputPath);
+        File compressedImage = new File(outputPath);
+        long compressedImageSize = compressedImage.length();
+
+        assertTrue(compressedImageSize < inputImageSize, "The compressed image is smaller in size");
+    }
+}

image-compressing/src/test/java/com/baeldung/image/compression/ThumbnailsCompressorUnitTest.java

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+package com.baeldung.image.compression;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ThumbnailsCompressorUnitTest {
+    @Test
+    void testCompressedImageIsSmaller() throws IOException {
+        String inputImagePath = ThumbnailsCompressor.class.getClassLoader()
+                .getResource("input.jpg").getPath();
+        File inputImage = new File(inputImagePath);
+        long inputImageSize = inputImage.length();
+        String outputPath = inputImagePath + "compressed.jpg";
+        ThumbnailsCompressor.compressImage(inputImagePath, outputPath);
+        File compressedImage = new File(outputPath);
+        long compressedImageSize = compressedImage.length();
+
+        assertTrue(compressedImageSize < inputImageSize, "The compressed image is smaller in size");
+    }
+}