java图片处理 文字水印 图片水印 缩放 补白

import java.awt.AlphaComposite; import java.awt.Color; import java.awt.Font; import java.awt.Graphics2D; import java.awt.Image; import java.awt.geom.AffineTransform; import java.awt.image.AffineTransformOp; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import javax.imageio.ImageIO; /** * @author Eric Xu * */ public final class ImageUtils { /** * 图片水印 * @param pressImg 水印图片 * @param targetImg 目标图片 * @param x 修正值 默认在中间 * @param y 修正值 默认在中间 * @param alpha 透明度 */ public final static void pressImage(String pressImg, String targetImg, int x, int y, float alpha) { try { File img = new File(targetImg); Image src = ImageIO.read(img); int wideth = src.getWidth(null); int height = src.getHeight(null); BufferedImage image = new BufferedImage(wideth, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); g.drawImage(src, 0, 0, wideth, height, null); //水印文件 Image src_biao = ImageIO.read(new File(pressImg)); int wideth_biao = src_biao.getWidth(null); int height_biao = src_biao.getHeight(null); g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha)); g.drawImage(src_biao, (wideth - wideth_biao) / 2, (height - height_biao) / 2, wideth_biao, height_biao, null); //水印文件结束 g.dispose(); ImageIO.write((BufferedImage) image, "jpg", img); } catch (Exception e) { e.printStackTrace(); } } /** * 文字水印 * @param pressText 水印文字 * @param targetImg 目标图片 * @param fontName 字体名称 * @param fontStyle 字体样式 * @param color 字体颜色 * @param fontSize 字体大小 * @param x 修正值 * @param y 修正值 * @param alpha 透明度 */ public static void pressText(String pressText, String targetImg, String fontName, int fontStyle, Color color, int fontSize, int x, int y, float alpha) { try { File img = new File(targetImg); Image src = ImageIO.read(img); int width = src.getWidth(null); int height = src.getHeight(null); BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); g.drawImage(src, 0, 0, width, height, null); g.setColor(color); g.setFont(new Font(fontName, fontStyle, fontSize)); g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha)); g.drawString(pressText, (width - (getLength(pressText) * fontSize)) / 2 + x, (height - fontSize) / 2 + y); g.dispose(); ImageIO.write((BufferedImage) image, "jpg", img); } catch (Exception e) { e.printStackTrace(); } } /** * 缩放 * @param filePath 图片路径 * @param height 高度 * @param width 宽度 * @param bb 比例不对时是否需要补白 */ public static void resize(String filePath, int height, int width, boolean bb) { try { double ratio = 0.0; //缩放比例 File f = new File(filePath); BufferedImage bi = ImageIO.read(f); Image itemp = bi.getScaledInstance(width, height, bi.SCALE_SMOOTH); //计算比例 if ((bi.getHeight() > height) || (bi.getWidth() > width)) { if (bi.getHeight() > bi.getWidth()) { ratio = (new Integer(height)).doubleValue() / bi.getHeight(); } else { ratio = (new Integer(width)).doubleValue() / bi.getWidth(); } AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(ratio, ratio), null); itemp = op.filter(bi, null); } if (bb) { BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); g.setColor(Color.white); g.fillRect(0, 0, width, height); if (width == itemp.getWidth(null)) g.drawImage(itemp, 0, (height - itemp.getHeight(null)) / 2, itemp.getWidth(null), itemp.getHeight(null), Color.white, null); else g.drawImage(itemp, (width - itemp.getWidth(null)) / 2, 0, itemp.getWidth(null), itemp.getHeight(null), Color.white, null); g.dispose(); itemp = image; } ImageIO.write((BufferedImage) itemp, "jpg", f); } catch (IOException e) { e.printStackTrace(); } } public static void main(String[] args) throws IOException { pressImage("G:\\imgtest\\sy.jpg", "G:\\imgtest\\test1.jpg", 0, 0, 0.5f); pressText("我是文字水印", "G:\\imgtest\\test1.jpg", "黑体", 36, Color.white, 80, 0, 0, 0.3f); resize("G:\\imgtest\\test1.jpg", 500, 500, true); } public static int getLength(String text) { int length = 0; for (int i = 0; i < text.length(); i++) { if (new String(text.charAt(i) + "").getBytes().length > 1) { length += 2; } else { length += 1; } } return length / 2; } }