jpeg

pom.xml

@@ -18,13 +18,13 @@
 		<dependency>
 			<groupId>org.junit.jupiter</groupId>
 			<artifactId>junit-jupiter-engine</artifactId>
-			<version>5.10.0</version>
+			<version>5.10.1</version>
 			<scope>test</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.junit.jupiter</groupId>
 			<artifactId>junit-jupiter-params</artifactId>
-			<version>5.10.0</version>
+			<version>5.10.1</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>
@@ -42,7 +42,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-compiler-plugin</artifactId>
-				<version>3.11.0</version>
+				<version>3.12.1</version>
 				<configuration>
 					<release>21</release>
 				</configuration>
@@ -72,12 +72,12 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-surefire-plugin</artifactId>
-				<version>3.1.2</version>
+				<version>3.2.3</version>
 			</plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-failsafe-plugin</artifactId>
-				<version>3.1.2</version>
+				<version>3.2.3</version>
 			</plugin>
 
 			<plugin>

src/main/java/ch/alpine/tensor/ext/Jpeg.java

@@ -0,0 +1,35 @@
+// adapted by jph
+package ch.alpine.tensor.ext;
+
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.util.Iterator;
+
+import javax.imageio.IIOImage;
+import javax.imageio.ImageIO;
+import javax.imageio.ImageWriteParam;
+import javax.imageio.ImageWriter;
+import javax.imageio.stream.ImageOutputStream;
+
+public enum Jpeg {
+  ;
+  /** Reference:
+   * https://stackoverflow.com/questions/13204432/java-how-to-set-jpg-quality
+   * 
+   * @param bufferedImage
+   * @param object
+   * @param quality
+   * @throws IOException */
+  public static void put(BufferedImage bufferedImage, Object object, float quality) throws IOException {
+    try (ImageOutputStream imageOutputStream = ImageIO.createImageOutputStream(object)) {
+      Iterator<ImageWriter> iterator = ImageIO.getImageWritersByFormatName("jpeg");
+      ImageWriter imageWriter = iterator.next();
+      ImageWriteParam imageWriteParam = imageWriter.getDefaultWriteParam();
+      imageWriteParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
+      imageWriteParam.setCompressionQuality(quality);
+      imageWriter.setOutput(imageOutputStream);
+      imageWriter.write(null, new IIOImage(bufferedImage, null, null), imageWriteParam);
+      imageWriter.dispose();
+    }
+  }
+}

src/main/java/ch/alpine/tensor/img/ImageResize.java

@@ -40,10 +40,9 @@ public enum ImageResize {
    * @param bufferedImage
    * @param width of rescaled image
    * @param height of rescaled image
-   * @return scaled instance of given buffered image with given dimensions and type
-   * either BufferedImage.TYPE_BYTE_GRAY or BufferedImage.TYPE_INT_ARGB */
+   * @return scaled instance of given buffered image with given dimensions */
   public static BufferedImage of(BufferedImage bufferedImage, int width, int height) {
-    BufferedImage result = new BufferedImage(width, height, StaticHelper.type(bufferedImage.getType()));
+    BufferedImage result = new BufferedImage(width, height, bufferedImage.getType());
     Graphics graphics = result.createGraphics();
     // TODO TENSOR IMPL improve results
     Image image = bufferedImage.getScaledInstance(width, height, Image.SCALE_AREA_AVERAGING);

src/main/java/ch/alpine/tensor/img/ImageRotate.java

@@ -1,6 +1,8 @@
 // code by jph
 package ch.alpine.tensor.img;
 
+import java.awt.image.BufferedImage;
+
 import ch.alpine.tensor.Tensor;
 import ch.alpine.tensor.Tensors;
 import ch.alpine.tensor.Unprotect;
@@ -41,4 +43,16 @@ public static Tensor _180(Tensor tensor) {
   private static int cols(Tensor tensor) {
     return Integers.requirePositive(Unprotect.dimension1(tensor));
   }
+
+  /** @param bufferedImage
+   * @return */
+  public static BufferedImage cw(BufferedImage bufferedImage) {
+    int width = bufferedImage.getWidth();
+    int height = bufferedImage.getHeight();
+    BufferedImage result = new BufferedImage(height, width, bufferedImage.getType());
+    for (int i = 0; i < width; ++i)
+      for (int j = 0; j < height; ++j)
+        result.setRGB(height - 1 - j, i, bufferedImage.getRGB(i, j));
+    return result;
+  }
 }

src/main/java/ch/alpine/tensor/img/Thumbnail.java

@@ -37,9 +37,8 @@ public static BufferedImage of(BufferedImage bufferedImage, int size) {
     Dimension dimension = h <= w //
         ? new Dimension(s.multiply(r).number().intValue(), size)
         : new Dimension(size, s.divide(r).number().intValue());
-    BufferedImage result = new BufferedImage(size, size, StaticHelper.type(bufferedImage.getType()));
+    BufferedImage result = new BufferedImage(size, size, bufferedImage.getType());
     Graphics2D graphics = result.createGraphics();
-    // TODO TENSOR IMPL improve results
     Image image = bufferedImage.getScaledInstance(dimension.width, dimension.height, Image.SCALE_AREA_AVERAGING);
     graphics.drawImage(image, (size - dimension.width) / 2, (size - dimension.height) / 2, null);
     graphics.dispose();

src/main/java/ch/alpine/tensor/io/ExportHelper.java

@@ -11,6 +11,7 @@
 import javax.imageio.ImageIO;
 
 import ch.alpine.tensor.Tensor;
+import ch.alpine.tensor.ext.Jpeg;
 
 /* package */ enum ExportHelper {
   ;
@@ -28,6 +29,8 @@ public static void of(Filename filename, Tensor tensor, OutputStream outputStrea
       of(extension, tensor, outputStream);
   }
 
+  private static final float JPG_QUALITY = 0.98f;
+
   /** @param extension
    * @param tensor
    * @param outputStream
@@ -38,7 +41,8 @@ public static void of(Extension extension, Tensor tensor, OutputStream outputStr
     case CSV -> lines(XsvFormat.CSV.of(tensor), outputStream);
     case TSV -> lines(XsvFormat.TSV.of(tensor), outputStream);
     case VECTOR -> lines(VectorFormat.of(tensor), outputStream);
-    case BMP, JPG -> ImageIO.write(ImageFormat.bgr(tensor), extension.name(), outputStream);
+    case BMP -> ImageIO.write(ImageFormat.bgr(tensor), extension.name(), outputStream);
+    case JPG -> Jpeg.put(ImageFormat.bgr(tensor), outputStream, JPG_QUALITY);
     case GIF, PNG, TIFF -> ImageIO.write(ImageFormat.of(tensor), extension.name(), outputStream);
     case M -> lines(MatlabExport.of(tensor), outputStream);
     default -> throw new UnsupportedOperationException(extension.name());