iText二进制透明错误
我遇到了以下问题:使用iText将透明的java.awt.Image嵌入pdf(使用2.1.7和5.5.9进行了尝试) 我想在这种特殊情况下,当将二进制透明图像从ARGB图像转换为iText图像时,iText无法正确处理它们 当提供的图像仅包含100%和0%的透明像素(即二进制透明),且所有像素均为黑色(不透明像素和透明像素-即图像的所有像素的颜色=黑色,但alpha值为0%或100%)时,透明像素颜色值在内部检测为黑色(我认为这是错误的),这将导致生成的pdf中出现不可见图像 测试用例:iText二进制透明错误,itext,Itext,我遇到了以下问题:使用iText将透明的java.awt.Image嵌入pdf(使用2.1.7和5.5.9进行了尝试) 我想在这种特殊情况下,当将二进制透明图像从ARGB图像转换为iText图像时,iText无法正确处理它们 当提供的图像仅包含100%和0%的透明像素(即二进制透明),且所有像素均为黑色(不透明像素和透明像素-即图像的所有像素的颜色=黑色,但alpha值为0%或100%)时,透明像素颜色值在内部检测为黑色(我认为这是错误的),这将导致生成的pdf中出现不可见图像 测试用例: im
import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import com.itextpdf.text.BadElementException;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfWriter;
public class BinaryTransparencyBug {
private static Image bkgnd;
public static void main(String[] args) throws Exception {
bkgnd = Image.getInstance(new URL("http://gitlab.itextsupport.com/itext/sandbox/raw/master/resources/images/berlin2013.jpg"));
bkgnd.scaleAbsolute(PageSize.A4);
bkgnd.setAbsolutePosition(0, 0);
Document document = new Document();
File file = new File("target/binary_transparency_bug.pdf");
FileOutputStream outputStream = new FileOutputStream(file);
PdfWriter writer = PdfWriter.getInstance(document, outputStream);
document.open();
addBackground(writer);
document.add(new Paragraph("Binary transparency bug test case"));
document.add(new Paragraph("OK: Visible image (opaque pixels are red, non opaque pixels are black)"));
document.add(com.itextpdf.text.Image.getInstance(createBinaryTransparentAWTImage(Color.red,false,null), null));
document.newPage();
addBackground(writer);
document.add(new Paragraph("Suspected bug: invisible image (both opaque an non opaque pixels have the same color)"));
document.add(com.itextpdf.text.Image.getInstance(createBinaryTransparentAWTImage(Color.black,false,null), null));
document.newPage();
addBackground(writer);
document.add(new Paragraph("Analysis: Aliasing makes the problem disappear, because this way the image is not binary transparent any more"));
document.add(com.itextpdf.text.Image.getInstance(createBinaryTransparentAWTImage(Color.black,true,null), null));
document.newPage();
addBackground(writer);
document.add(new Paragraph("Analysis: Setting the color of the transparent pixels to anything but black makes the problem go away, too"));
document.add(com.itextpdf.text.Image.getInstance(createBinaryTransparentAWTImage(Color.black,false,Color.red), null));
document.close();
}
private static void addBackground(PdfWriter writer)
throws BadElementException, MalformedURLException, IOException, DocumentException {
PdfContentByte canvas = writer.getDirectContentUnder();
canvas.saveState();
canvas.addImage(bkgnd);
canvas.restoreState();
}
// Create an ARGB AWT Image that has only 100% transparent and 0%
// transparent pixels.
// All 100% opaque pixels have the provided color "color"
// All transparent pixels have the Color "backgroundColor"
public static BufferedImage createBinaryTransparentAWTImage(Color color, boolean alias, Color backgroundColor) {
Dimension size = new Dimension(200, 200);
BufferedImage awtimg = new BufferedImage(size.width, size.height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = awtimg.createGraphics();
if (backgroundColor!=null)
{
//Usually it doen't make much sense to set the color of transparent pixels...
//but in this case it changes the behavior of com.itextpdf.text.Image.getInstance fundamentally!
g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC, 0f));
g2d.setColor(backgroundColor);
g2d.fillRect(0, 0, size.width, size.height);
}
g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 1f));
g2d.setColor(color);
if (alias)
{
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
}
BasicStroke bs = new BasicStroke(2);
g2d.setStroke(bs);
for (int i = 0; i < 5; i++) {
g2d.drawLine((size.width + 2) / 4 * i, 0, (size.width + 2) / 4 * i, size.height - 1);
g2d.drawLine(0, (size.height + 2) / 4 * i, size.width - 1, (size.height + 2) / 4 * i);
}
return awtimg;
}
}
导入java.awt.AlphaComposite;
导入java.awt.BasicStroke;
导入java.awt.Color;
导入java.awt.Dimension;
导入java.awt.Graphics2D;
导入java.awt.RenderingHints;
导入java.awt.image.buffereImage;
导入java.io.File;
导入java.io.FileOutputStream;
导入java.io.IOException;
导入java.net.MalformedURLException;
导入java.net.URL;
导入com.itextpdf.text.BadElementException;
导入com.itextpdf.text.Document;
导入com.itextpdf.text.DocumentException;
导入com.itextpdf.text.Image;
导入com.itextpdf.text.PageSize;
导入com.itextpdf.text.paragration;
导入com.itextpdf.text.pdf.PdfContentByte;
导入com.itextpdf.text.pdf.PdfWriter;
公共类二进制透明bug{
私有静态图像bkgnd;
公共静态void main(字符串[]args)引发异常{
bkgnd=Image.getInstance(新URL(“http://gitlab.itextsupport.com/itext/sandbox/raw/master/resources/images/berlin2013.jpg"));
bkgnd.可缩放溶质(页面大小A4);
bkgnd.setAbsolutePosition(0,0);
文档=新文档();
File File=新文件(“target/binary_transparency_bug.pdf”);
FileOutputStream outputStream=新的FileOutputStream(文件);
PdfWriter writer=PdfWriter.getInstance(文档,outputStream);
document.open();
背景(作者);
添加(新段落(“二进制透明错误测试用例”);
添加(新段落(“确定:可见图像(不透明像素为红色,非不透明像素为黑色)”);
add(com.itextpdf.text.Image.getInstance(createBinaryTransparentAWTImage(Color.red,false,null),null));
document.newPage();
背景(作者);
添加(新段落(“可疑缺陷:不可见图像(不透明和非不透明像素颜色相同)”);
add(com.itextpdf.text.Image.getInstance(createBinaryTransparentAWTImage(Color.black,false,null),null));
document.newPage();
背景(作者);
添加(新的段落(“分析:别名使问题消失,因为这样图像不再是二进制透明的”);
add(com.itextpdf.text.Image.getInstance(createBinaryTransparentAWTImage(Color.black,true,null),null));
document.newPage();
背景(作者);
添加(新段落(“分析:将透明像素的颜色设置为除黑色以外的任何颜色都会使问题消失”);
add(com.itextpdf.text.Image.getInstance(createBinaryTransparentAWTImage(Color.black,false,Color.red),null));
document.close();
}
私有静态void addBackground(PdfWriter编写器)
抛出BadElementException、MalformedURLException、IOException、DocumentException{
PdfContentByte canvas=writer.getDirectContentUnder();
canvas.saveState();
canvas.addImage(bkgnd);
canvas.restoreState();
}
//创建只有100%透明和0%透明的ARGB AWT图像
//透明像素。
//所有100%不透明像素都具有提供的颜色“颜色”
//所有透明像素的颜色均为“backgroundColor”
公共静态缓冲区图像CreateBaryTransparentAwtImage(颜色、布尔别名、颜色背景色){
尺寸尺寸=新尺寸(200200);
BuffereImage awtimg=新的BuffereImage(size.width、size.height、BuffereImage.TYPE_INT_ARGB);
Graphics2D g2d=awtimg.createGraphics();
if(backgroundColor!=null)
{
//通常设置透明像素的颜色没有多大意义。。。
//但在本例中,它从根本上改变了com.itextpdf.text.Image.getInstance的行为!
setComposite(AlphaComposite.getInstance(AlphaComposite.SRC,0f));
g2d.setColor(背景色);
g2d.fillRect(0,0,size.width,size.height);
}
setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER,1f));
g2d.setColor(彩色);
如果(别名)
{
g2d.setRenderingHint(renderingHits.KEY\u抗锯齿,renderingHits.VALUE\u抗锯齿\u开启);
g2d.setRenderingHint(RenderingHits.KEY\u插值,RenderingHits.VALUE\u插值\u双线性);
}
基本行程bs=新的基本行程(2);
g2d.调整行程(bs);
对于(int i=0;i<5;i++){
g2d.绘图线((尺寸.宽度+2)/4*i,0,(尺寸.宽度+2)/4*i,尺寸.高度-1);
g2d.绘图线(0,(尺寸高度+2)/4*i,尺寸宽度-1,(尺寸高度+2)/4*i);
}
返回awtimg;
}
}
以下是我的解决方案:
在Image.getInstance中(AWTImage、color、forcebw):
在forceBW=false和color=null的情况下:
for (int j = 0; j < size; j++) {
byte alpha = smask[j] = (byte) (pixels[j] >> 24 & 0xff);
/* bugfix by Chris Nokleberg */
if (!shades) {
if (alpha != 0 && alpha != -1) {
//as soon as there is any pixel with alpha not 0% or 100%
//switch to smask
shades = true;
} else if (transparency == null) {
//in binary transparency mode, determine the transparentPixel Color to be the
//value of the first Pixel we find with 100% transparency
if (alpha == 0) {
transparentPixel = pixels[j] & 0xffffff;
transparency = new int[6];
transparency[0] = transparency[1] = transparentPixel >> 16 & 0xff;
transparency[2] = transparency[3] = transparentPixel >> 8 & 0xff;
transparency[4] = transparency[5] = transparentPixel & 0xff;
// vvv--- added by mkl
// Check whether this value for transparent pixels
// has already been used for a non-transparent one
// before this position
for (int jj = 0; jj < j; jj++)
{
if ((pixels[jj] & 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
shades = true;
break;
}
}
// ^^^--- added by mkl
}
} else if (((pixels[j] & 0xffffff) != transparentPixel) && (alpha==0)) {
//TB: The above if seems incorrect to me. (EDIT: it was if ((pixels[j] & 0xffffff) != transparentPixel)
//As soon as we find any pixel that has differnt color from
//transparentPixel-Color and alpha 0% or 100%
//switch of binary transparency mode.
//IMHO this should only be done if alpha==0!
//so the if clause should be
//((pixels[j] & 0xffffff) != transparentPixel) && (alpha==0)
shades = true;
}
//TB: Proposed fix:
else if ((pixels[j] & 0xffffff) == transparentPixel && alpha!=0) {
//switch of binary transparency mode, if we find any pixel with the transparentPixel-Color,
//but which is not transparent
shades = true;
}
}
...
}
for(int j=0;j>24&0xff);
/*克里斯·诺克伯格的错误修正*/
如果(!阴影){
如果(alpha!=0&&alpha!=-1){
//一旦出现alpha不是0%或100%的像素
//切换到smask
阴影=真实;
}else if(透明度==null){
//在“二进制透明度”模式下,确定要显示的透明度像素颜色