保留图片 alpha channel 信息，设置 gif 透明背景，建议使用 png 图片源

hellodk34 · May 5, 2022 · 27db7e3 · 27db7e3
1 parent a7abb99
commit 27db7e3
Show file tree

Hide file tree

Showing 2 changed files with 14 additions and 0 deletions.
diff --git a/app.jar b/app.jar
diff --git a/src/main/java/MainService.java b/src/main/java/MainService.java
@@ -1,6 +1,7 @@
 import cn.hutool.core.img.gif.AnimatedGifEncoder;
 
 import javax.imageio.ImageIO;
+import java.awt.Color;
 import java.awt.image.BufferedImage;
 import java.io.File;
 import java.nio.file.Path;
@@ -44,11 +45,24 @@ public void jpg2gif(String imgFolder, String outputFolder) throws Exception {
         File[] tempList = file.listFiles();
         if (tempList != null && tempList.length > 0) {
             for (int i = 0; i < tempList.length; i++) {
+                // TODO 处理一下图片的 alpha channel 问题，保存原本的透明背景
                 File tempFile = tempList[i];
                 String tempFileName = tempFile.getName();
                 BufferedImage src = ImageIO.read(tempFile);
                 AnimatedGifEncoder gifEncoder = new AnimatedGifEncoder();
+                // 循环模式,0代表无限循环
                 gifEncoder.setRepeat(0);
+
+                // 保留原图的 alpha channel 信息，设置 gif 背景图为透明
+                /**
+                 * new rgba color
+                 * red
+                 * green
+                 * blue
+                 * alpha
+                 * 255,255,255 是白色 效果差强人意(勉强使人满意)
+                 */
+                gifEncoder.setTransparent(new Color(255, 255, 255, src.getColorModel().getTransparency()), true);
                 int lastDot = tempFileName.lastIndexOf('.');
                 String newFileName = tempFileName.substring(0, lastDot) + ".gif";
                 System.out.println("current sequence is " + (i + 1) + " and output file name is " + newFileName);