Speed up page thumb generation

[Jelle Nagels]

Hi,

I have an Android application that needs to generate thumbnails of every page in a lot of pdf-files.

It all works perfectly, except that it is too slow. It takes about 600-700ms per page, which means a pdf document of 140 page takes 1 minute and 38 seconds to generate pdf's, which is too slow.

Is there anything I can do to improve the performance of my code ?

final float maxDimension = 320;

PDFDoc pdfDoc = null;

PDFDraw pdfDraw = null;

try

{

//encoder parameters!

ObjSet objSet = new ObjSet();

Obj encoder_param = objSet.createDict();

encoder_param.putNumber("Quality", sQuality);

Log.d(getClass().getSimpleName(), "Preparing file " + pdfPath );

pdfDoc = new PDFDoc(pdfPath);

pdfDraw = new PDFDraw();

pdfDraw.setDrawAnnotations(false);

pdfDraw.setImageSmoothing(false);

pdfDraw.setCaching(false);

int pageCount = pdfDoc.getPageCount();

File thumbFile;

Page page = null;

for(int pageNr = 1 ; pageNr <= pageCount; pageNr++)

{

//create thumbnail path

thumbFile = new File(getThumbnailPath(pdfPathWithoutExt, pageNr));

Log.d("PdfPreparer", "Preparing page " + pageNr + " in file : "+ thumbFile.toString());

if (thumbFile.exists())

{

//the thumbnail already 

continue;

}

long start = System.currentTimeMillis();

try

{

//get the page to render it to a bitmap

page = pdfDoc.getPage(pageNr);

float w = (float) page.getPageWidth();

float h = (float) page.getPageHeight();

if (w > h && w > 0)

{

h = h * ((float)maxDimension / w);

w = maxDimension;

}

else if (h > 0)

{

w = w * ((float)maxDimension / h);

h = maxDimension;

}

pdfDraw.setImageSize((int)w, (int)h);

pdfDraw.export(page, thumbFile.getPath(), "PNG8", encoder_param);

}

catch(Exception e)

{

e.printStackTrace();

}

finally

{

if (page != null) { page = null; }

}

Log.d("PDF", "Decoging page took: " + (System.currentTimeMillis() - start) + " milliseconds");

}

}

catch(Exception e)

{

Log.e("PdfPreparer",e.getMessage(), e);

}

finally

{

if (pdfDoc != null)

{

try{

pdfDoc.close();

}catch (PDFNetException e){

Log.e("PdfPreparer",e.getMessage(), e);

}

}

if (pdfDraw != null)

{

try{

pdfDraw.destroy();

}catch (PDFNetException e){

Log.e("PdfPreparer",e.getMessage(), e);

}

}

}

[Fabien Molinet]

Hi Jelle,

Have you found a solution to this? If yes could you share what you did?