Java修改图片png格式透明背景大小分辨率

来源：互联网发布：社交网络电影编辑：程序博客网时间：2024/05/16 13:51
import java.awt.Graphics2D;import java.awt.Image;import java.awt.Transparency;import java.awt.image.BufferedImage;import java.io.File;import javax.imageio.ImageIO;/** * 图片工具类 */public class ImageUtil {/** * 裁剪PNG图片工具类 *  * @param fromFile *            源文件 * @param toFile *            裁剪后的文件 * @param outputWidth *            裁剪宽度 * @param outputHeight *            裁剪高度 * @param proportion *            是否是等比缩放 */public static void resizePng(File fromFile, File toFile, int outputWidth, int outputHeight,boolean proportion) {try {BufferedImage bi2 = ImageIO.read(fromFile);int newWidth;int newHeight;// 判断是否是等比缩放if (proportion) {// 为等比缩放计算输出的图片宽度及高度double rate1 = ((double) bi2.getWidth(null)) / (double) outputWidth + 0.1;double rate2 = ((double) bi2.getHeight(null)) / (double) outputHeight + 0.1;// 根据缩放比率大的进行缩放控制double rate = rate1 < rate2 ? rate1 : rate2;newWidth = (int) (((double) bi2.getWidth(null)) / rate);newHeight = (int) (((double) bi2.getHeight(null)) / rate);} else {newWidth = outputWidth; // 输出的图片宽度newHeight = outputHeight; // 输出的图片高度}BufferedImage to = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_RGB);Graphics2D g2d = to.createGraphics();to = g2d.getDeviceConfiguration().createCompatibleImage(newWidth, newHeight,Transparency.TRANSLUCENT);g2d.dispose();g2d = to.createGraphics();@SuppressWarnings("static-access")Image from = bi2.getScaledInstance(newWidth, newHeight, bi2.SCALE_AREA_AVERAGING);g2d.drawImage(from, 0, 0, null);g2d.dispose();ImageIO.write(to, "png", toFile);} catch (Exception e) {e.printStackTrace();}}/** * 测试 */public static void main(String[] args) throws Exception {File fromFile = new File("c:/1.png");File toFile = new File("c:/2.png");resizePng(fromFile, toFile, 100, 100, false);}}
1 0