Pull request #9399: REPORT-103847 导出后蓝色图片不显示

Merge in CORE/base-third from ~OBO/base-third:bugfix/11.0 to bugfix/11.0

* commit 'f07bced888f5b8ade34265b15a6338c0e0208366':
  REPORT-103847 单测
  REPORT-103847 优化补充内容
  REPORT-103847 导出后蓝色图片不显示

fine-itext-old/src/main/java/com/fr/third/com/lowagie/text/Image.java

@@ -753,12 +753,30 @@ public abstract class Image extends Rectangle {
 						} else if (transparency == null) {
 							if (alpha == 0) {
 								transparentPixel = pixels[j] & 0xffffff;
+								// Added by Michael Klink
+								// Check whether this value for transparent pixels
+								// has already been used for a non-transparent one
+								// before this position
+								for (int prevPixel = 0; prevPixel < j; prevPixel++) {
+									if ((pixels[prevPixel] & 0xffffff) == transparentPixel) {
+										// found a prior use of the transparentPixel color
+										// and, therefore, cannot make use of this color
+										// for transparency; we could still use an image
+										// mask but for simplicity let's use a soft mask
+										// which already is implemented here
+										// stackOverFlow：https://stackoverflow.com/questions/39119776/itext-binary-transparency-bug
+										shades = true;
+										break;
+									}
+								}
 								transparency = new int[6];
 								transparency[0] = transparency[1] = (transparentPixel >> 16) & 0xff;
 								transparency[2] = transparency[3] = (transparentPixel >> 8) & 0xff;
 								transparency[4] = transparency[5] = transparentPixel & 0xff;
 							}
-						} else if ((pixels[j] & 0xffffff) != transparentPixel) {
+						} else if (((pixels[j] & 0xffffff) != transparentPixel) && (alpha == 0)) {
+							shades = true;
+						} else if (((pixels[j] & 0xffffff) == transparentPixel) && (alpha != 0)) {
 							shades = true;
 						}
 					}

fine-itext-old/test/com/fr/third/com/lowagie/text/ImageTest.java

@@ -0,0 +1,108 @@
+import com.fr.third.com.lowagie.text.Document;
+import com.fr.third.com.lowagie.text.RectangleReadOnly;
+import com.fr.third.com.lowagie.text.pdf.PdfContentByte;
+import com.fr.third.com.lowagie.text.pdf.PdfGraphics2D;
+import com.fr.third.com.lowagie.text.pdf.PdfTemplate;
+import com.fr.third.com.lowagie.text.pdf.PdfWriter;
+import org.junit.Test;
+import org.junit.Assert;
+
+import javax.imageio.ImageIO;
+import java.awt.Color;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.Arrays;
+
+
+
+/**
+ * Image单元测试类
+ * 不在打包范围内，只是留个凭证，需要自己添加junit 依赖才能跑
+ *
+ * @author obo
+ * @since 11.0
+ * Created on 2023/9/6
+ */
+public class ITextDrawPdfImageTest {
+
+    @Test
+    public void testDrawOpaqueAndTransparentImage() throws Exception {
+        // 创建文档对象
+        Document document = new Document(new RectangleReadOnly(90,90));
+        // 创建PdfWriter以将文档写入文件
+        PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("actual.pdf"));
+        BufferedImage image = ImageIO.read(new File("transparent_image.png"));
+
+        Assert.assertTrue(checkImageValid(image));
+
+        // 打开文档
+        document.open();
+
+        // 获取PdfContentByte用于在PDF页面上绘制内容
+        PdfContentByte contentByte = writer.getDirectContent();
+
+        // 创建PdfTemplate，作为图形容器
+        PdfTemplate template = contentByte.createTemplate(90, 90);
+        PdfGraphics2D graphics2D = (PdfGraphics2D) template.createGraphics(90, 90);
+
+        // 在Graphics2D上绘制图像或其他内容
+        graphics2D.drawImage(image, 0, 0, null);
+
+        // 释放Graphics2D资源
+        graphics2D.dispose();
+
+        // 将PdfTemplate添加到PDF页面
+        contentByte.addTemplate(template, 0, 0); // X, Y 坐标
+        // 关闭文档
+        document.close();
+
+        File actual = new File("actual.pdf");
+        File expect = new File("expect.pdf");
+
+        Assert.assertTrue(checkFilesEqual(actual, expect));
+    }
+
+
+    private boolean checkFilesEqual(File actual, File expect) throws IOException {
+        byte[] actualBytes = Arrays.copyOfRange(Files.readAllBytes(actual.toPath()), 0, 1024);
+        byte[] expectBytes = Arrays.copyOfRange(Files.readAllBytes(expect.toPath()), 0, 1024);
+
+        return java.util.Arrays.equals(actualBytes, expectBytes);
+    }
+
+    /**
+     * 检查Image是否是一种完全透明颜色+一种完全不透明颜色构成的
+     */
+    private boolean checkImageValid(BufferedImage image) {
+        int transparentColor = -1, unTransparentColor = -1;
+
+        int width = image.getWidth();
+        int height = image.getHeight();
+
+        for (int x = 0; x < width; x++) {
+            for (int y = 0; y < height; y++) {
+                int rgb = image.getRGB(x, y);
+                int alpha = (rgb >> 24) & 0xFF;
+                int color = rgb & 0xFFFFFF;
+                if(alpha == 0) {
+                    if (transparentColor == -1) {
+                        transparentColor = color;
+                    } else if (transparentColor != color) {
+                        return false;
+                    }
+                }
+                if(alpha == 255) {
+                    if (unTransparentColor == -1) {
+                        unTransparentColor = color;
+                    } else if (unTransparentColor != color) {
+                        return false;
+                    }
+                }
+            }
+        }
+        return true;
+    }
+}