Example how to render all PDF pages to images

ville
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IP: 212.149.240.8 6 years 8 months ago - 6 years 8 months ago #14360 by ville

Example how to render all PDF pages to images was created by ville

Hi!

I need to export all pdf pages to jpeg images at the resolution of 1080x1920. How can this be done with this library? (Looking for code examples.)

Last edit: 6 years 8 months ago by ville.

radaee
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IP: 111.196.246.50 6 years 8 months ago - 6 years 8 months ago #14362 by radaee

Replied by radaee on topic Example how to render all PDF pages to images

the codes like:

Code:

Global.Init(this);
Document doc = new Document();
doc.Open("pdf path");
int pcnt = doc.GetPageCount();
int pcur = 0;
while(pcur < pcnt)
{
  float pw = doc.GetPageWidth(pcur);
  float ph = doc.GetPageHeight(pcur);
  int bw = (int)(pw * scale);
  int bh = (int)(ph * scale);
  Bitmap bmp = Bitmap.Create(bw, bh, RGBA8888);
  bmp.erase(white);
  Matrix mat = new Matrix(scale, -scale, 0, bh);
  Page page = doc.GetPage(pcur);
  page.RenderToBmp(mat, bmp);
  page.Close();
  bmp.Compress(...);
  pcur++;
}
doc.Close();

Last edit: 6 years 8 months ago by radaee.

ville
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IP: 85.76.5.49 6 years 8 months ago #14364 by ville

Replied by ville on topic Example how to render all PDF pages to images

It seems that there are unfortunately multiple PDFs that aren't opening with this library. I've attached one as an example here:

support
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IP: 37.183.44.177 6 years 8 months ago #14365 by support

Replied by support on topic Example how to render all PDF pages to images

The attached file was just rendered with current demo project:

Screenshot_20190520_183253_com.radaee.reader.jpg

May you provide the result you're receiving and what you're expecting?

ville
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IP: 85.76.5.49 6 years 8 months ago #14366 by ville

Replied by ville on topic Example how to render all PDF pages to images

Now that I'm debugging it it seems that for string

Code:

content://com.android.externalstorage.documents/document/151B-4307%3ADownload%2FElisa_90292596604.pdf

the resulting document contains 0 pages.

So it seems that the

Code:

document.Open(uri.toString())

is not working as expected. How should it be loaded?

radaee
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IP: 111.196.244.118 6 years 8 months ago #14367 by radaee

Replied by radaee on topic Example how to render all PDF pages to images

them example on this topic is openging local File from absolute path.
for url you need PDFHTTPStream.

Code:

Global.Init(this);
PDFHTTPStream stream = new PDFHTTPStream("http://you addr/your pdf");
Document doc = new Document();
doc.OpenStream(stream);
int pcnt = doc.GetPageCount();
int pcur = 0;
while(pcur < pcnt)
{
  float pw = doc.GetPageWidth(pcur);
  float ph = doc.GetPageHeight(pcur);
  int bw = (int)(pw * scale);
  int bh = (int)(ph * scale);
  Bitmap bmp = Bitmap.Create(bw, bh, RGBA8888);
  bmp.erase(white);
  Matrix mat = new Matrix(scale, -scale, 0, bh);
  Page page = doc.GetPage(pcur);
  page.RenderToBmp(mat, bmp);
  page.Close();
  bmp.Compress(...);
  pcur++;
}
doc.Close();
stream.Close();

the webserver shall support "ByteRange" header for http request, and you need Internet Permission declared in AndroidMenifest.xml.

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