增加图片透明度设置。

picc-enterprise-server/src/test/java/com/jpsoft/picc/test/ImageTest.java

@@ -0,0 +1,60 @@
+package com.jpsoft.picc.test;
+
+import javax.imageio.ImageIO;
+import javax.swing.*;
+import java.awt.*;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+public class ImageTest {
+    public static void main(String[] args) {
+        System.out.println(transferAlpha2File("E:\\印章1.png", "E:\\透明印章.png"));
+    }
+
+    public static boolean transferAlpha2File(String imgSrc, String imgTarget) {
+        File file = new File(imgSrc);
+        InputStream is = null;
+        boolean result = false;
+        try {
+            is = new FileInputStream(file);
+            // 如果是MultipartFile类型，那么自身也有转换成流的方法：is = file.getInputStream();
+            BufferedImage bi = ImageIO.read(is);
+            Image image = (Image) bi;
+            ImageIcon imageIcon = new ImageIcon(image);
+            BufferedImage bufferedImage = new BufferedImage(imageIcon.getIconWidth(), imageIcon.getIconHeight(),
+                    BufferedImage.TYPE_4BYTE_ABGR);
+            Graphics2D g2D = (Graphics2D) bufferedImage.getGraphics();
+            g2D.drawImage(imageIcon.getImage(), 0, 0, imageIcon.getImageObserver());
+            int alpha = 0;
+            for (int j1 = bufferedImage.getMinY(); j1 < bufferedImage.getHeight(); j1++) {
+                for (int j2 = bufferedImage.getMinX(); j2 < bufferedImage.getWidth(); j2++) {
+                    int rgb = bufferedImage.getRGB(j2, j1);
+                    int R = (rgb & 0xff0000) >> 16;
+                    int G = (rgb & 0xff00) >> 8;
+                    int B = (rgb & 0xff);
+                    if (((255 - R) < 30) && ((255 - G) < 30) && ((255 - B) < 30)) {
+                        rgb = ((alpha + 1) << 24) | (rgb & 0x00ffffff);
+                    }
+                    bufferedImage.setRGB(j2, j1, rgb);
+                }
+            }
+            g2D.drawImage(bufferedImage, 0, 0, imageIcon.getImageObserver());
+            result = ImageIO.write(bufferedImage, "png", new File(imgTarget));// 直接输出文件
+        } catch (Exception e) {
+            e.printStackTrace();
+            result = false;
+        } finally {
+            if (is != null) {
+                try {
+                    is.close();
+                } catch (IOException e) {
+                    // TODO Auto-generated catch block
+                }
+            }
+        }
+        return result;
+    }
+}