Here is how I split a large PDF (144 mb):
public int SplitAndSave(string inputPath, string outputPath)
{
FileInfo file = new FileInfo(inputPath);
string name = file.Name.Substring(0, file.Name.LastIndexOf("."));
using (PdfReader reader = new PdfReader(inputPath))
{
for (int pagenumber = 1; pagenumber <= reader.NumberOfPages; pagenumber++)
{
string filename = pagenumber.ToString() + ".pdf";
Document document = new Document();
PdfCopy copy = new PdfCopy(document, new FileStream(outputPath + "\\" + filename, FileMode.Create));
document.Open();
copy.AddPage(copy.GetImportedPage(reader, pagenumber));
document.Close();
}
return reader.NumberOfPages;
}
}
For most PDFs (small size, and I guess old format), all works fine. But for a bigger one (that perhaps are using something like refstreams for better compression), the split pages open as one page, but its size is equal to the original PDF's size. What can I do?
In case of your document Top_Gear_Magazine_2012_09.pdf the reason is indeed the one I mentioned: All pages refer to object 2 0 R as their /Resources, and the dictionary in 2 0 obj in turn references all images in the PDF.
To split that document into partial documents containing only the images required, you should preprocess the document by first finding out which images belong to which pages and then creating individual /Resources dictionaries for all pages.
As you already use iText in this context, you can also use it to find out which images are required for which pages. Use the iText parser package to initially parse the PDF page by page using a RenderListener implementation whose RenderImage method simply remembers which image objects are used on the current page. (As a special twist, iText hides the name of the image XObject in question; you get the indirect object, though, and can query its object and generation number which suffices for the next step.)
In a second step, you open the document in a PdfStamperand iterate over the pages. For each page you retrieve the /Resources dictionary and copy it, but only copy those XObjects references referencing one of the image objects whose object number and generation you remembered for the respective page during the first step. Finally you set the diminished copy as the /Resources dictionary of the page in question.
The resulting PDF should split just fine.
PS A very similar issue recently came up on the iText mailing list. In that thread the solution recipe given here has been improved, to get around the difficulties caused by iText hiding the xobject name, I now would propose to intervene before the name is lost by using a different ContentOperator for "Do", here the Java version:
class Do implements ContentOperator
{
public void invoke(PdfContentStreamProcessor processor, PdfLiteral operator, ArrayList<PdfObject> operands) throws IOException
{
PdfName xobjectName = (PdfName)operands.get(0);
names.add(xobjectName);
}
final List<PdfName> names = new ArrayList<PdfName>();
}
This content operator simply collects the names of the used xobjects, i.e. the xobject resources to keep for the given page.
Related
private void addPageNumbers(Document doc)
{
var totalPages = doc.GetPdfDocument().GetNumberOfPages();
for (int i = 1; i <= totalPages; i++)
{
// Write aligned text to the specified by parameters point
doc.ShowTextAligned(new Paragraph(string.Format("page %s of %s", i, totalPages)),
559, 806, i, TextAlignment.RIGHT, VerticalAlignment.TOP, 0);
}
doc.Close();
}
this is the code i tried, but I get the following exception:
iText.Kernel.PdfException: "Cannot draw elements on already flushed
pages."
I need to add the page numbers in the end because after generating the content of the pdf I generate a table of contents and move it to the beginning of the document. Therefore i only know the page numbers after generating all the pages.
iText by default tries to flush pages (i.e. write their contents to the PdfWriter target stream and free them in memory) early which is shortly after you started the next page. To such a flushed page you obviously cannot add your page x of y header anymore.
There are some ways around this. For example, if you have enough resources available and don't need that aggressive, early flushing, you can switch it of by using a different Document constructor, the one with an extra boolean parameter immediateFlush, and setting this parameter to false.
Thus, instead of
new Document(pdfDoc)
or
new Document(pdfDoc, pageSize)
use
new Document(pdfDoc, pageSize, false)
This is a related answer.
I'm generating PDF files using PDFsharp, and I need to overlay the PDF I'm generating with a specific page from another PDF.
I've created this method:
private void ApplyOverlay(XGraphics graph, string overlaypdfPath, int pageNumberInOverlay, XRect coordinates)
{
var xPdf = XPdfForm.FromFile(overlaypdfPath);
if(xPdf.PageCount < pageNumberInOverlay)
throw new Exception("not enough pages");
//Here i need to take from xPdf just the page number -> pageNumberInOverlay
graph.DrawImage(xPdfPageN, coordinates);
}
I don’t know how to select only a specific page.
You can append the page number to the name of the PDF file, separated with a hash sign ("#").
To get page 7 of "sample.pdf", use the filename "sample.pdf#6" (zero-based page numbers).
Is it possible using IText to copy PDF pages from a full PDF document and return partial document based on a form field name? For example I need to copy the beginning of a pdf document and stop at a certain text field called [STOP_HERE], so whatever contents before this fields need to be extracted, the [STOP_HERE] field could be located on a different page for each document, so using page numbers wouldn't help here.
I searched online and all I can find is a way to copy only form fields from a document but not the whole document elements including images texts with their exact location and style.
Can IText do the job here?
EDIT: More details
[STOP_HERE] is an AcroForms text field which has been placed in a document by the PDF design person to indicate that everything before this element should be copied as is into a different document. The field itself is not important, I don't want to fill or do anything with it, it's just used as a signal to let the document parser stop there and copy all previous (upper) contents, I just don't know how to read all contents (without changing style, contents, etc) before this field.
Is it possible using IText to copy PDF pages from a full PDF document and return partial document based on a form field name? For example I need to copy the beginning of a pdf document and stop at a certain text field called [STOP_HERE]
Unfortunately the OP didn't tell whether the page containing the form field [STOP_HERE] is to be included or not. As that is a mere +/-1 matter, though, I simply assumed the page is to be included.
Thus, the task can be implemented like this:
PdfReader reader = new PdfReader(srcFile);
AcroFields.Item field = reader.AcroFields.Fields["[STOP_HERE]"];
if (field != null)
{
int firstPage = reader.NumberOfPages + 1;
for (int index = 0; index < field.Size; index++)
{
int page = field.GetPage(index);
if (page > 0 && page < firstPage)
firstPage = page;
}
if (firstPage <= reader.NumberOfPages)
{
reader.SelectPages("1-" + firstPage);
PdfStamper stamper = new PdfStamper(reader, new FileStream(dstFile, FileMode.Create, FileAccess.Write));
stamper.Close();
}
}
reader.Close();
The code opens the source file in a PdfReader and first looks for the field. If it exists, it iterates over all appearances of that field and determines the earliest page with an appearance of the field. If there is such a page, the code restricts the reader to the pages up to that page and stores this restriction using a PdfStamper.
I have a problem when I'm working with image PDF files (PDF file with image only, no text) There are two PDF files img1, img2 and I want to combine two of them into one A4 page PDF file.
I have tried below code.
string Img1 = "C:/temp/image1.pdf";
string Img2 = "C:/temp/image2.pdf";
string MergedFile = "C:/temp/Combo.pdf";
//Create our PDF readers
PdfReader r1 = new PdfReader(Img1);
PdfReader r2 = new PdfReader(Img2);
//Our new page size, an A3 in landscape mode
iTextSharp.text.Rectangle NewPageSize = PageSize.A3.Rotate();
using (FileStream fs = new FileStream(MergedFile, FileMode.Create,
FileAccess.Write, FileShare.None))
{
//Create our document without margins
using (Document doc = new Document(NewPageSize, 0, 0, 0, 0))
{
using (PdfWriter w = PdfWriter.GetInstance(doc, fs))
{
doc.Open();
//Get our imported pages
PdfImportedPage imp1 = w.GetImportedPage(r1, 1);
PdfImportedPage imp2 = w.GetImportedPage(r2, 1);
//Add them to our merged document at specific X/Y coords
**w.DirectContent.AddTemplate(imp1, 0, 0);
w.DirectContent.AddTemplate(imp2, 0, -350);**
doc.Close();
}
}
}
r1.Close();
r2.Close();
So when i execute above code, because i have mentioned the y coord , it will combine pdf and two images will be on one page only.
BUt i don't want to do that
Here i am just giving example of two images,but in actual there are more than 20 images (converted into PDFs).
So depending on the image size, it should combine files. i can not give fix y coord for each n every file
Can anyone please help me to combine multiple PDF into single with no blank space..?
Structurally, here is what you want to do:
Allocate a new page of the "right" size
Merge the content streams of the pages
Merge the resources of the pages
Adjust all the annotations (if any)
The first step is easy, the rest, the second is easy, the third not so much (and will have the side effect of complicating step 2). I'll let you know ahead of time that I lied to you about the order.
Merging the content streams will be straight forward. What you will want to do is a four step process (I'll inject here that I know PDF very well, but iTextSharp not too well):
Insert a gsave operator (q)
Insert a transform operator (cm) to transform to the location where you want content to appear. In you case it will be 1 0 0 1 X Y cm
Copy the content streams from the current page
Insert a grestore operator (Q)
To merge the resources, you have to look at your newly created page's resources and for the current page do one of three things for each resource in each class of resource in a PDF page (XObject, Font, ColorSpace, ExtGState, Pattern, Shading, ProcSet - although for procset, you could set each procset to be the entire suite and do no harm):
If the resource exists in the newly created page, but under a different name, mark it as renamed.
If the resource does not exist in the newly created page and there is no resource with the same name, copy it in.
If the resource does not exist in the newly created page and there is a name conflict, rename the resource to a synthetic name not in the newly create page and copy it in.
Now to get back to my lie. In the resource merging, you will likely need a map built for the current page that maps old resource name to new resource name. When in the process of copying the content stream from one to the next, you will need to map all resource names referenced in the content stream to the new names built in the resource merge step.
To Adjust annotations, you will have to move them to their new location by adjusting the Rect property in each. You will also need to reset the /Parent property. For any of the text markup annotations, you will need to adjust the Quads.
Now, here is where the works will get gummed up in all of that. If a page is rotated, this will not work. If a page has a crop box, you will have to look at it and adjust the clipping region to simulate the crop. If the page is rotated and has Text annotations, this will need to attention to annotation flags to ensure that the aspect ratio is correct. If the document has link annotations on any of the pages with GoTo actions/destinations, you will need to adjust these.
I am generating a pdf using iTextSharp. If certain properties are true then I also want to insert an existing pdf with static content.
private byte[] GeneratePdf(DraftOrder draftOrder)
// create a pdf document
var document = new Document();
// set the page size, set the orientation
document.SetPageSize(PageSize.A4);
// create a writer instance
var pdfWriter = PdfWriter.GetInstance(document, new FileStream(file, FileMode.Create));
document.Open();
if(draftOrder.hasProperty){
//add these things to the pdf
var textToBeAdded = "<table><tr>....</table>";
}
FormatHtml(document, textToBeAdded , css);
if(someOtherProperty){
//add static pdf from file
document.NewPage();
var reader = new PdfReader("myPath/existing.pdf");
PdfImportedPage page;
for(var i = 0; i < reader.NumberOfPages; i++){
//It's this bit I don't really understand
//**how can I add the page read to the document being created?**
}
I can load the pdf from the source but when I iterate over the pages I can't seem to be able to add them to the document I am creating.
Cheers
Please read http://manning.com/lowagie2/samplechapter6.pdf
If you don't mind losing all interactivity, you can get the template from the writer object with the GetImportedPage() method and add it to the document with AddTemplate ().
This question has been answered many times on StackOverflow and you'll notice that I always warn about some dangers: you need to realize that the dimensions of the imported page can be different from the page size you initially defined. Because of this invisible parts of the imported page can become visible; visible parts can become invisible.
I'd prefer adding the extra page in a second ho using PdfCopy, but maybe that's just me.