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如何将“来自图像的印章注释”导出到图像文件？

我有一个包含戳记注释的 pdf（实际上它是一个图像），我想将所有这些类型的图像导出到文件并获取 x/y 位置。

我是pdf新手。任何想法或代码将不胜感激。

[--- 编辑于 2019/08/08 ---]

    private void btnExtractAnnotaion_Click(object sender, EventArgs e)
    {
        PdfReader reader = new PdfReader(this.txtPdf.Text);
        PdfDictionary pageDict = reader.GetPageN(reader.NumberOfPages);
        PdfArray annotArray = pageDict.GetAsArray(PdfName.ANNOTS);
        PdfObject annot = null;
        Console.WriteLine("Annotation count:{0}", annotArray.Size);
        for (int i = 0; i < annotArray.Size; i++)
        {
            annot = annotArray.GetDirectObject(i);
            Console.WriteLine(annot.ToString());
            //curAnnot = annotArray.GetAsDict(i);
            //Console.WriteLine(curAnnot.ToString());
            bool btmp = annot.IsDictionary();
            if (btmp)
            {
                PdfDictionary pdfDic = ((PdfDictionary)annot);
                PdfName stamp = pdfDic.GetAsName(PdfName.SUBTYPE);
                if (stamp.Equals(PdfName.STAMP))
                {
                    //PdfObject img = pdfDic.GetDirectObject(PdfName.RECT);
                    // How Can I get the image(png, jpg...) of Stamp?
                }
            }
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2 回答 2

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@mkl @FastJack 感谢您的宝贵时间！通过这个答案ImageRenderListener

它解决了我的问题。以下是我的代码：

PdfReader reader = new PdfReader(this.txtPdf.Text);
PdfDictionary pageDict = reader.GetPageN(reader.NumberOfPages);
PdfArray annotArray = pageDict.GetAsArray(PdfName.ANNOTS);

//Console.WriteLine("Annotation count:{0}", annotArray.Size);
for (int i = 0; i < annotArray.Size; i++)
{
    PdfObject annot = annotArray.GetDirectObject(i);
    //Console.WriteLine(annot.ToString());
    bool btmp = annot.IsDictionary();
    if (btmp)
    {
        PdfDictionary pdfDic = ((PdfDictionary)annot);
        PdfName stamp = pdfDic.GetAsName(PdfName.SUBTYPE);
        if (stamp.Equals(PdfName.STAMP))
        {
            // rects are laid out [llx, lly, urx, ury]
            float x, y, width, height;
            PdfArray rect = pdfDic.GetAsArray(PdfName.RECT);
            x = rect.GetAsNumber(0).FloatValue;
            y = rect.GetAsNumber(1).FloatValue;
            width = rect.GetAsNumber(2).FloatValue - x;
            height = rect.GetAsNumber(3).FloatValue - y;

            PdfDictionary appearancesDic = pdfDic.GetAsDict(PdfName.AP);
            PdfStream normalAppearance = appearancesDic.GetAsStream(PdfName.N);
            PdfDictionary resourcesDic = ormalAppearance.GetAsDict(PdfName.RESOURCES);

            ImageRenderListener listener = new ImageRenderListener();
            PdfContentStreamProcessor processor = new PdfContentStreamProcessor(listener);
            processor.ProcessContent(
                ContentByteUtils.GetContentBytesFromContentObject(normalAppearance),                 resourcesDic);

            System.Drawing.Image drawingImage = listener.Images.First();
            //Image image = Image.GetInstance(drawingImage, drawingImage.RawFormat);
        }
    }
}
于 2019-08-12T08:37:01.610 回答
0

iText7 正是您想要使用的东西。;)

https://www.nuget.org/packages/itext7/

https://itextpdf.com/en/products/itext-7

这就是您可以访问邮票的方式，具体取决于所使用的冲压技术：

using (PdfReader r = new PdfReader("input.pdf"))
using (PdfDocument doc = new PdfDocument(r))
{
    var annotations = doc.GetPage(1).GetAnnotations();
}

在其他情况下，这可以解决问题：

using (PdfReader r = new PdfReader("input.pdf"))
using (PdfDocument doc = new PdfDocument(r))
{
    var res = doc.GetFirstPage().GetResources();
}

除非您提供演示 PDF，否则我可以为您提供所有帮助

于 2019-08-02T08:00:17.547 回答