PDFsharp & MigraDoc Foundation

Hello,

Can anyone please tell me how can i get following information from indivdual pdf pages.

- page is BW,grayscale or color
- page size
- DPI
etc...


Thanks
Gaurav Dixit
Software Engineer,
Pune, India

PDF pages have no DPI (all vector). You can calculate the DPI for every raster image on a page.

BW or colour: you must look at every item on that page.

Page size: it's there, just use it.

_________________
Öhmesh Volta ("() => true")
PDFsharp Team Holiday Substitute

Hi!
I've a question to the current post. How can I check DPI of images contained by pdf file?
I'm trying to do something like this:

using (PdfDocument pdf = PdfReader.Open(sourcePdf))
{
for (int i = 0; i < pdf.Pages.Count; i++)
{
XGraphics xGraphics = XGraphics.FromPdfPage(pdf.Pages[i]);
float dpi = xGraphics.Graphics.DpiX;
}
}

but DPI is not correct.(For example it shows 96dpi while it should be 150dpi).

I've also tried to get such info from XObject dictionary but there're no such property like DPI
PdfDocument pdf = PdfReader.Open(sourcePdf);
PdfDictionary pg = pdf.Pages[0];
PdfDictionary res = pg.Elements.GetDictionary("/Resources");
PdfDictionary xobj = res.Elements.GetDictionary("/XObject");// there're width, height and so on but no dpi

PDF pages have no DPI (all vector).
If you have an image with a width of 300 pixels and you draw it in the PDF file with a width of one inch, the image will have 300 DPI when printed.
If you have an image with a width of 300 pixels and you draw it in the PDF file with a width of three inches, the image will have 100 DPI when printed.
Take the width in pixels, take the width in inches and calculate the DPI.

_________________
Regards
Thomas Hoevel
PDFsharp Team