/* ImageUtils.java
* --------------------------------------
* CREATED ON Jun 19, 2006 4:44:25 AM
*
* MSN arden.emily@msn.com
* QQ 103099587（太阳里的雪）
* MOBILE 13590309275
*
* ALL RIGHTS RESERVED BY ZHENUU CO,.LTD.
* --------------------------------------
*/
package com.jrails.commons.utils;
import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.plugins.jpeg.JPEGImageWriteParam;
import javax.imageio.stream.ImageOutputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.image.PixelGrabber;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.Iterator;
import java.util.Locale;
/**
* Utilities methods for image manipulation.
* It does not support writting of GIF images, but it
* can read from. GIF images will be saved as PNG.
* <p/>
* Date: Jun 19, 2006 4:44:25 AM
*
* @author <a href="arden.emily@gmail.com">arden</a>
*/
public class ImageUtils {
public static final int IMAGE_UNKNOWN = -1;
public static final int IMAGE_JPEG = 0;
public static final int IMAGE_PNG = 1;
public static final int IMAGE_GIF = 2;
/**
* Resizes an image
*
* @param imgName The image name to resize. Must be the complet path to the file
* @param maxWidth The image's max width
* @param maxHeight The image's max height
* @return A resized <code>BufferedImage</code>
* @throws IOException If the file is not found
*/
public static BufferedImage resizeImage(File file, int type, int maxWidth, int maxHeight) throws IOException {
return resizeImage(ImageIO.read(file), type, maxWidth, maxHeight);
}
/**
* Resizes an image
*
* @param imgName The image name to resize. Must be the complet path to the file
* @param maxWidth The image's max width
* @param maxHeight The image's max height
* @return A resized <code>BufferedImage</code>
* @throws IOException If the file is not found
*/
public static BufferedImage resizeImage(String imgName, int type, int maxWidth, int maxHeight) throws IOException {
return resizeImage(ImageIO.read(new File(imgName)), type, maxWidth, maxHeight);
}
public static BufferedImage resizeImage(URL url, int type, int maxWidth, int maxHeight) throws IOException {
return resizeImage(ImageIO.read(url), type, maxWidth, maxHeight);
}
/**
* Resizes an image.
*
* @param image The image to resize
* @param maxWidth The image's max width
* @param maxHeight The image's max height
* @return A resized <code>BufferedImage</code>
*/
public static BufferedImage resizeImage(Image image, int type, int maxWidth, int maxHeight) {
Dimension largestDimension = new Dimension(maxWidth, maxHeight);
// Original size
int imageWidth = image.getWidth(null);
int imageHeight = image.getHeight(null);
float aspectRation = (float) imageWidth / imageHeight;
if (imageWidth > maxWidth || imageHeight > maxHeight) {
if ((float) largestDimension.width / largestDimension.height > aspectRation) {
largestDimension.width = (int) Math.ceil(largestDimension.height * aspectRation);
} else {
largestDimension.height = (int) Math.ceil(largestDimension.width / aspectRation);
}
imageWidth = largestDimension.width;
imageHeight = largestDimension.height;
}
return createBufferedImage(image, type, imageWidth, imageHeight);
}
/**
* Saves an image to the disk.
*
* @param image The image to save
* @param toFileName The filename to use
* @param type The image type. Use <code>ImageUtils.IMAGE_JPEG</code> to save as JPEG
* images, or <code>ImageUtils.IMAGE_PNG</code> to save as PNG.
* @return <code>false</code> if no appropriate writer is found
* @throws IOException
*/
public static boolean saveImage(BufferedImage image, String toFileName, int type) throws IOException {
return ImageIO.write(image, type == IMAGE_JPEG ? "jpg" : "png", new File(toFileName));
}
/**
* Compress and save an image to the disk.
* Currently this method only supports JPEG images.
*
* @param image The image to save
* @param toFileName The filename to use
* @param type The image type. Use <code>ImageUtils.IMAGE_JPEG</code> to save as JPEG
* images, or <code>ImageUtils.IMAGE_PNG</code> to save as PNG.
* @param compress Set to <code>true</code> if you want to compress the image.
* @return <code>false</code> if no appropriate writer is found
* @throws IOException
*/
@SuppressWarnings("unchecked")
public static void saveCompressedImage(BufferedImage image, String toFileName, int type) throws IOException {
if (type == IMAGE_PNG) {
throw new UnsupportedOperationException("PNG compression not implemented");
}
ImageWriter writer = null;
Iterator iter = ImageIO.getImageWritersByFormatName("jpg");
writer = (ImageWriter) iter.next();
ImageOutputStream ios = ImageIO.createImageOutputStream(new File(toFileName));
writer.setOutput(ios);
ImageWriteParam iwparam = new JPEGImageWriteParam(Locale.getDefault());
iwparam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
iwparam.setCompressionQuality(0.7F);
writer.write(null, new IIOImage(image, null, null), iwparam);
ios.flush();
writer.dispose();
ios.close();
}
/**
* Creates a <code>BufferedImage</code> from an <code>Image</code>.
*
* @param image The image to convert
* @param w The desired image width
* @param h The desired image height
* @return The converted image
*/
public static BufferedImage createBufferedImage(Image image, int type, int w, int h) {
if (type == ImageUtils.IMAGE_PNG && hasAlpha(image)) {
type = BufferedImage.TYPE_INT_ARGB;
} else {
type = BufferedImage.TYPE_INT_RGB;
}
BufferedImage bi = new BufferedImage(w, h, type);
Graphics g = bi.createGraphics();
g.drawImage(image, 0, 0, w, h, null);
g.dispose();
return bi;
}
/**
* Determines if the image has transparent pixels.
*
* @param image The image to check for transparent pixel.s
* @return <code>true</code> of <code>false</code>, according to the result
* @throws InterruptedException
*/
public static boolean hasAlpha(Image image) {
try {
PixelGrabber pg = new PixelGrabber(image, 0, 0, 1, 1, false);
pg.grabPixels();
return pg.getColorModel().hasAlpha();
} catch (InterruptedException e) {
return false;
}
}
}