图片等比例缩放
http://my.oschina.net/vitoh/blog/491478
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Java代码 import java.awt.Color; import java.awt.Graphics; import java.awt.Image; import java.awt.image.BufferedImage; import java.awt.image.ConvolveOp; import java.awt.image.Kernel; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import javax.swing.ImageIcon; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGEncodeParam; import com.sun.image.codec.jpeg.JPEGImageEncoder; /** * 图片等比例缩放工具 * @Author vitoHuang * @Time 2015年8月12日 * @Mark */ public class ImageUtil { /** * * @param originalFile 原图片文件 * @param resizedFile 缩放后文件 * @throws IOException */ public static void resize(File originalFile, File resizedFile)throws IOException { resize(originalFile,resizedFile,640); } /** * * @param originalFile 原图片文件 * @param resizedFile 缩放后文件 * @param newWidth 缩放后宽度 单位：px * @throws IOException */ public static void resize(File originalFile, File resizedFile,int newWidth)throws IOException { resize(originalFile, resizedFile, newWidth,1F); } /** * * @param originalFile 原图片文件 * @param resizedFile 缩放后文件 * @param newWidth 缩放后宽度 单位：px * @param quality 质量 0-1之间 * @throws IOException */ public static void resize(File originalFile, File resizedFile,int newWidth, float quality) throws IOException { if (quality > 1) throw new IllegalArgumentException("质量必须是0和1之间"); ImageIcon ii = new ImageIcon(originalFile.getCanonicalPath()); Image i = ii.getImage(); Image resizedImage = null; int iWidth = i.getWidth(null); int iHeight = i.getHeight(null); //根据提供的新图片宽度 if (iWidth > iHeight) { resizedImage = i.getScaledInstance(newWidth, (newWidth * iHeight) / iWidth, Image.SCALE_SMOOTH); }else{ resizedImage = i.getScaledInstance((newWidth * iWidth) / iHeight,newWidth, Image.SCALE_SMOOTH); } //确保在加载图像中的所有像素 Image temp = new ImageIcon(resizedImage).getImage(); //创建图片缓存 BufferedImage bufferedImage = new BufferedImage(temp.getWidth(null),temp.getHeight(null), BufferedImage.TYPE_INT_RGB); //复制图像缓冲图像 Graphics g = bufferedImage.createGraphics(); g.setColor(Color.white); g.fillRect(0, 0, temp.getWidth(null), temp.getHeight(null)); g.drawImage(temp, 0, 0, null); g.dispose(); float softenFactor = 0.05f; float[] softenArray = { 0, softenFactor, 0, softenFactor,1 - (softenFactor * 4), softenFactor, 0, softenFactor, 0 }; Kernel kernel = new Kernel(3, 3, softenArray); ConvolveOp cOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null); bufferedImage = cOp.filter(bufferedImage, null); FileOutputStream out = new FileOutputStream(resizedFile); // 编码图像作为JPEG数据流 JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out); JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bufferedImage); param.setQuality(quality, true); encoder.setJPEGEncodeParam(param); encoder.encode(bufferedImage); } } |
