图片工具类，完成图片的截取,缩放(ImageHepler )

编程技术  /  houtizong 发布于 3年前   102

package com.lz.hr_picture.helper;import java.awt.Graphics2D;import java.awt.Rectangle;import java.awt.RenderingHints;import java.awt.geom.AffineTransform;import java.awt.image.BufferedImage;import java.awt.image.ColorModel;import java.awt.image.WritableRaster;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import javax.imageio.ImageIO;/** * 图片工具类，完成图片的截取 * * @author penghuaiyi * @date 2010-11-10 */public class ImageHepler {    /**     * 实现图像的等比缩放     * @param source     * @param targetW     * @param targetH     * @return     */    private static BufferedImage resize(BufferedImage source, int targetW,            int targetH) {        // targetW，targetH分别表示目标长和宽        int type = source.getType();        BufferedImage target = null;        double sx = (double) targetW / source.getWidth();        double sy = (double) targetH / source.getHeight();        // 这里想实现在targetW，targetH范围内实现等比缩放。如果不需要等比缩放        // 则将下面的if else语句注释即可        if (sx < sy) {            sx = sy;            targetW = (int) (sx * source.getWidth());        } else {            sy = sx;            targetH = (int) (sy * source.getHeight());        }        if (type == BufferedImage.TYPE_CUSTOM) { // handmade            ColorModel cm = source.getColorModel();            WritableRaster raster = cm.createCompatibleWritableRaster(targetW,                    targetH);            boolean alphaPremultiplied = cm.isAlphaPremultiplied();            target = new BufferedImage(cm, raster, alphaPremultiplied, null);        } else            target = new BufferedImage(targetW, targetH, type);        Graphics2D g = target.createGraphics();        // smoother than exlax:        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,                RenderingHints.VALUE_INTERPOLATION_BICUBIC);        g.drawRenderedImage(source, AffineTransform.getScaleInstance(sx, sy));        g.dispose();        return target;    }    /**     * 实现图像的等比缩放和缩放后的截取     * @param inFilePath 要截取文件的路径     * @param outFilePath 截取后输出的路径     * @param width 要截取宽度     * @param hight 要截取的高度     * @param proportion     * @throws Exception     */    public static void saveImageAsJpg(String inFilePath, String outFilePath,            int width, int hight, boolean proportion)throws Exception {         File file = new File(inFilePath);         InputStream in = new FileInputStream(file);         File saveFile = new File(outFilePath);        BufferedImage srcImage = ImageIO.read(in);        if (width > 0 || hight > 0) {            // 原图的大小            int sw = srcImage.getWidth();            int sh = srcImage.getHeight();            // 如果原图像的大小小于要缩放的图像大小，直接将要缩放的图像复制过去            if (sw > width && sh > hight) {                srcImage = resize(srcImage, width, hight);            } else {                String fileName = saveFile.getName();                String formatName = fileName.substring(fileName                        .lastIndexOf('.') + 1);                ImageIO.write(srcImage, formatName, saveFile);                return;            }        }        // 缩放后的图像的宽和高        int w = srcImage.getWidth();        int h = srcImage.getHeight();        // 如果缩放后的图像和要求的图像宽度一样，就对缩放的图像的高度进行截取        if (w == width) {            // 计算X轴坐标            int x = 0;            int y = h / 2 - hight / 2;            saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile);        }        // 否则如果是缩放后的图像的高度和要求的图像高度一样，就对缩放后的图像的宽度进行截取        else if (h == hight) {            // 计算X轴坐标            int x = w / 2 - width / 2;            int y = 0;            saveSubImage(srcImage, new Rectangle(x, y, width, hight), saveFile);        }        in.close();    }    /**     * 实现缩放后的截图     * @param image 缩放后的图像     * @param subImageBounds 要截取的子图的范围     * @param subImageFile 要保存的文件     * @throws IOException     */    private static void saveSubImage(BufferedImage image,            Rectangle subImageBounds, File subImageFile) throws IOException {        if (subImageBounds.x < 0 || subImageBounds.y < 0                || subImageBounds.width - subImageBounds.x > image.getWidth()                || subImageBounds.height - subImageBounds.y > image.getHeight()) {            System.out.println("Bad   subimage   bounds");            return;        }        BufferedImage subImage = image.getSubimage(subImageBounds.x,subImageBounds.y, subImageBounds.width, subImageBounds.height);        String fileName = subImageFile.getName();        String formatName = fileName.substring(fileName.lastIndexOf('.') + 1);        ImageIO.write(subImage, formatName, subImageFile);    }    public static void main(String[] args)throws Exception{    ImageHepler.saveImageAsJpg("E:\\证书图片\\1.jpg", "E:\\pics\\1.jpg", 600, 400, true);    }}