Extracting portion of a PDF - pdf

Question

I'm trying to extract a portion of a pdf (the coordinates of the section will always remain constant) using PDF Sharp. Then I will resize the portion to 4" x 6" for printing onto a sticky back label. How would I extract the portion of the PDF? This is in a console application, C#.

Answer 1

There is no easy way to extract parts from a PDF file.
A possible workaround: create a new page in label size, then draw the existing page onto the new page so that the required rectangle is visible on the new page.
If needed, draw white rectangles to hide information that is not part of the section you need, but that is visible on the new page.

Answer 2

So here was how I managed to do this, not a perfect solution (you do loose some quality). This uses Spire.PDF, not PDF Sharp as I originally planned. I got fairly lucky in that the output size was nearly 4" X 6". So I just used shrink to fit on print options.
static void Main(string[] args)
{
ConvertPDFToBmp("FilePathOfPDF");
CropAtRect("FilePathOfConvertedImage");
ConvertToPDF("FilePathOfCroppedImage");
}
public static void ConvertPDFToBmp(string filePath)
{
PdfDocument document = new PdfDocument();
document.LoadFromFile(filePath);
Image emf = document.SaveAsImage(0, Spire.Pdf.Graphics.PdfImageType.Bitmap, 400, 400);
emf.Save("FilePath", ImageFormat.Jpeg);
}
public static void CropAtRect(string filePath)
{
Bitmap b = (Bitmap)Bitmap.FromFile(filePath);
Rectangle r = new Rectangle(new /*Where the rectangle starts*/Point(/*Width*/, /*Height*/), (new /*How big is the rectangle*/Size(/*Width*/, /*Height*/)));
Bitmap nb = new Bitmap(r.Width, r.Height);
nb.SetResolution(400, 400); //Scale to keep quality
Graphics g = Graphics.FromImage(nb);
g.DrawImage(b, -r.X, -r.Y);
nb.Save("FilePath", ImageFormat.Jpeg);
}
public static void ConvertToPDF(string filePath)
{
Bitmap b = (Bitmap)Bitmap.FromFile(filePath);
PdfDocument doc = new PdfDocument();
PdfImage pdfImage = PdfImage.FromImage(b);
PdfUnitConvertor uinit = new PdfUnitConvertor();
PdfPageBase page = doc.Pages.Add(new /*Size of PDF Page*/SizeF(585, 365), new PdfMargins(0f));
page.Canvas.DrawImage(pdfImage, new /*Where the image starts*/PointF(0, 0));
doc.SaveToFile("FilePath");
}