From b08709beca30891d29b3608a0de36699f2537744 Mon Sep 17 00:00:00 2001 From: erik Date: Thu, 3 Aug 2006 18:45:55 +0000 Subject: [PATCH] --- gps/src/org/wamblee/utils/JpegUtils.java | 108 +++++++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 gps/src/org/wamblee/utils/JpegUtils.java diff --git a/gps/src/org/wamblee/utils/JpegUtils.java b/gps/src/org/wamblee/utils/JpegUtils.java new file mode 100644 index 00000000..abeea40a --- /dev/null +++ b/gps/src/org/wamblee/utils/JpegUtils.java @@ -0,0 +1,108 @@ +/* + * Copyright 2006 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.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 = JPEGCodec.createJPEGDecoder(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); + } + +} + -- 2.31.1