X-Git-Url: http://wamblee.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=src%2Fmain%2Fjava%2Forg%2Fwamblee%2Fphotos%2Futils%2FJpegUtils.java;fp=src%2Fmain%2Fjava%2Forg%2Fwamblee%2Fphotos%2Futils%2FJpegUtils.java;h=2b0a0e753e3d15c07c971449b900d78ae0c65fe4;hb=8845e7fe6141ccc98fd070ee4e653941f6e60508;hp=0000000000000000000000000000000000000000;hpb=b5dd7f771153492ebf5b70949dba8914af58a3cd;p=photos

diff --git a/src/main/java/org/wamblee/photos/utils/JpegUtils.java b/src/main/java/org/wamblee/photos/utils/JpegUtils.java
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+++ b/src/main/java/org/wamblee/photos/utils/JpegUtils.java
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+/*
+ * Copyright 2005 the original author or authors.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */ 
+package org.wamblee.photos.utils;
+
+import java.awt.Container;
+import java.awt.Graphics2D;
+import java.awt.Image;
+import java.awt.MediaTracker;
+import java.awt.RenderingHints;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import sun.awt.image.codec.JPEGImageDecoderImpl;
+
+import com.sun.image.codec.jpeg.JPEGCodec;
+import com.sun.image.codec.jpeg.JPEGEncodeParam;
+import com.sun.image.codec.jpeg.JPEGImageDecoder;
+import com.sun.image.codec.jpeg.JPEGImageEncoder;
+
+/**
+ * Utility functions for processing JPEG images. 
+ */
+public class JpegUtils {
+	/**
+	 * Scales an image preserving the aspect ratio. 
+	 * 
+	 * @param aMaxWidth Maximum width. 
+	 * @param aMaxHeight Maximum height. 
+	 * @param aImage Image to scale. 
+	 * @return Scaled image. 
+	 */
+	public static BufferedImage scaleImage(int aMaxWidth, int aMaxHeight, Image aImage) {
+        double thumbRatio = (double) aMaxWidth / (double) aMaxHeight;
+        int imageWidth = aImage.getWidth(null);
+        int imageHeight = aImage.getHeight(null);
+        double imageRatio = (double) imageWidth / (double) imageHeight;
+        if (thumbRatio < imageRatio) {
+            aMaxHeight = (int) (aMaxWidth / imageRatio);
+        } else {
+            aMaxWidth = (int) (aMaxHeight * imageRatio);
+        }
+		BufferedImage thumbImage = new BufferedImage(aMaxWidth, aMaxHeight,
+				BufferedImage.TYPE_INT_RGB);
+		Graphics2D graphics2D = thumbImage.createGraphics();
+		graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
+				RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+		graphics2D.drawImage(aImage, 0, 0, aMaxWidth, aMaxHeight, null);
+		return thumbImage;
+	}
+
+	/**
+	 * Loads a jpeg image from an input stream.
+	 *  
+	 * @param aInput Input stream. 
+	 * @return JPEG image. 
+	 * @throws IOException In case of IO problems.  
+	 * @throws InterruptedException When execution is interrupted. 
+	 */
+	public static BufferedImage loadJpegImage(InputStream aInput) throws IOException, InterruptedException {
+		JPEGImageDecoder decoder = new JPEGImageDecoderImpl(aInput);
+		BufferedImage image = decoder.decodeAsBufferedImage();
+		MediaTracker mediaTracker = new MediaTracker(new Container());
+		mediaTracker.addImage(image, 0);
+		mediaTracker.waitForID(0);
+		return image;
+	}
+
+	/**
+	 * Writes a JPEG image. 
+	 * 
+	 * @param aOutput Output stream to write to. 
+	 * @param aQuality Quality of the JPEG image in the range 0..100
+	 * @param aThumbImage
+	 * @throws IOException
+	 */
+	public static void writeJpegImage(OutputStream aOutput, int aQuality, BufferedImage aThumbImage) throws IOException {
+		// save thumbnail image to OUTFILE
+		
+		if ( aQuality < 0 || aQuality > 100 ) {
+			throw new IllegalArgumentException("Argument quality must be in range 0.100: " + aQuality); 
+		}
+			
+		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(aOutput);
+		JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(aThumbImage);
+		aQuality = Math.max(0, Math.min(aQuality, 100));
+		param.setQuality((float) aQuality / 100.0f, false);
+		encoder.setJPEGEncodeParam(param);
+		encoder.encode(aThumbImage);
+	}
+
+}