问题
we have created an application to generate pdf documents using itext 5 library. As the part of pdf generation, we tried to embed an image inline in pdf which should be non editable and read only. We tried with an addImage method of PdfContentByte as below,
byte[] decoded = Base64.getDecoder().decode(encodedImage);
image = Image.getInstance(decoded);
After this image is retrieved, used the same in addImage method.
PdfContentByte canvas = pdfStamper.getOverContent(item.getPage(0));
canvas.addImage(image, Boolean.TRUE);
Findings : Since the image is in Base 64 string format, the image is not displayed in the resultant pdf document (if the image is not in Base 64 format, it is working fine).
when we open the pdf , the below error is shown :-------> "An error exists on this page. Acrobat may not display the page correctly. Please contact the person who created the PDF document to correct the problem."
how can we handle this situation ?.
Is any other way to achieve this requirement. Please help
Code :-
PdfReader resultantPdfReader = new PdfReader("template.pdf");
PdfStamper resultandPdfStamper = new PdfStamper(resultantPdfReader, new FileOutputStream("A13.pdf"));
AcroFields acroFields = resultantPdfReader.getAcroFields();
Rectangle fieldPosRec = acroFields.getFieldPositions("imageField").get(0).position;
String encodedSignature = "";
encodedSignature = new String(Files.readAllBytes(Paths.get("MyImage.png")));
if(encodedSignature.indexOf("data:image/png;base64,") != -1) {
encodedSignature = encodedSignature.substring("data:image/png;base64,".length());
}
Image image = null;
try {
byte[] decoded = Base64.getDecoder().decode(encodedSignature);
image = Image.getInstance(decoded);
} catch (Exception e) {
e.printStackTrace();
}
image.scaleAbsoluteHeight(fieldPosRec.getHeight());
image.scaleAbsoluteWidth(fieldPosRec.getWidth());
image.scaleToFit(fieldPosRec);
acroFields.removeField("imageField");
image.setAbsolutePosition(fieldPosRec.getLeft(), fieldPosRec.getBottom());
PdfContentByte canvas = resultandPdfStamper.getOverContent(item.getPage(0));
canvas.addImage(image, Boolean.TRUE);
resultandPdfStamper.close();
resultantPdfReader.close();
Base64 Image String : 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
回答1:
Your example image has properties that iText cannot properly translate into an inlined image. Unfortunately it does not recognize this and outputs an erroneous result PDF.
In particular your image file uses transparency. Inline images don't allow for Mask or SMask entries (which images in PDFs use to represent transparency). Thus, your image as is cannot be used as inline image.
As a result the inline image created by iText only consists of a black rectangle while the transparency information (which contains the line drawing) is dropped.
Furthermore, your image uses a calibrated RGB color space. Such calibrated RGB color spaces cannot be inlined themselves, so the color space definition has to be put into the page resources. iText, though, when creating an inlined image, fails to reference that non-inlined part properly.
As a result the inline image created by iText references a color space by the wrong name, causing the "An error exists on this page" error message by Adobe Reader. Fixing that reference one gets a valid result PDF showing the black rectangle mentioned above.
In a comment you explain that your actual objective is to prevent copying image from the generated pdf document.
In general this obviously is not possible - any information a PDF viewer can access to draw on screen or paper also can be accessed by some PDF processor designed for that task to copy to some file. (Let's ignore proprietary, viewer specific DRM extensions here.)
What you can try, though, is draw your data in such a way that the common PDF viewers don't offer to copy it. Trying to use an inline image as you did is one approach in that direction. Other approaches wrap the image in other structures, e.g. in a pattern:
PdfContentByte canvas = resultandPdfStamper.getOverContent(1);
Rectangle pageSize = resultantPdfReader.getPageSize(1);
PdfPatternPainter painter = canvas.createPattern(pageSize.getWidth(), pageSize.getHeight());
painter.addImage(image);
canvas.setColorFill(new PatternColor(painter));
canvas.rectangle(0, 0, pageSize.getWidth(), pageSize.getHeight());
canvas.fill();
(AddImageInPattern test testAddToPageTest3)
Adobe Acrobat Reader here does not offer to copy that image. Also my (admittedly older) Adobe Acrobat Pro does not offer to copy it, merely to remove it (more exactly, remove the whole rectangle filled with the pattern).
Beware, though, what the common PDF viewers do or don't offer is a moving target...
来源：https://stackoverflow.com/questions/58224394/add-inline-image-in-pdf-document-using-itext-library