IPXC_Page.DrawToDevice has a performance issue

[kyo]

Dear All,
I use the method IPXC_Page.DrawToDevice() to generate thumbnails and that works fine if there is not a large number of pdf pages.
But,as the number of pdf pages increase,the performance is significantly decline.

For instance,I have a pdf with 19pages,and it will take about 5s to generate thumbnails from it that is much longer than your Eidtor SDK do.

I guess that maybe your Editor SDK use a different method or optimized parameters.

I have uploaded a screenshot containing the key code,and I hope it could provide all the information you need.

I hope you can help to analyse what cause the performance issue.

I am waiting for your reply anxiously.
Thanks in advance.

[Sasha - Tracker Dev Team]

Hello kyo,

The problem is that you are using the DrawToDevice method that is mainly used for printing and it should not be used as you are using it if we are talking about efficiency. The correct method to use would be DrawToIXCPage. Here's a small sample on how to use it:
https://forum.pdf-xchange.com/ ... 42#p101442
Also, check out this post - it contains a sample on how to convert a IIXC_Page to Bitmap and vise versa:
https://forum.pdf-xchange.com/ ... 97#p106897

Cheers,
Alex

[kyo]

Code: Select all

   uint Pt2Px(double nPoint, double nDPI)
   {
      return (uint)((nPoint / 72.0) * nDPI + 0.5);
   }

   //Creating empty dest IIXC_Page including DPI
   PDFXEdit.IIXC_Page iDestPage = iInst.Page_CreateEmpty(Pt2Px(nW, nDPI), Pt2Px(nH, nDPI), PDFXEdit.IXC_PageFormat.PageFormat_8RGB, 0x0000FF);

   //Creating destination image rect
   PDFXEdit.tagRECT destRect;
   destRect.left = 0;
   destRect.bottom = 0;
   destRect.right = (int)iDestPage.Width;
   destRect.top = (int)iDestPage.Height;
   //Getting page matrix
   PDFXEdit.PXC_Matrix srcPageMatrix = srcPage.GetMatrix(PDFXEdit.PXC_BoxType.PBox_PageBox);
   //Getting source page Page Box without rotation
   PDFXEdit.PXC_Rect srcRect = srcPage.get_Box(PDFXEdit.PXC_BoxType.PBox_PageBox);
   //Getting visual source Page Box by transforming it through matrix
   TransformRect(srcPageMatrix, ref srcRect);
   //Filling destination iPage with the image
   srcPage.DrawToIXCPage(iDestPage, ref destRect, ref srcPageMatrix);

The code above is from the link you give me in the last message.
I find that the struct PDFXEdit.PXC_Matrix is difficult to understand ,not to mention transforming it,so I want you give me the sample code to implement the function "TransformRect(srcPageMatrix, ref srcRect)".

I have done a test, if I ignore the function "TransformRect(srcPageMatrix, ref srcRect)",I will get an strange image.

Now,I need to know how to implement the function "TransformRect(srcPageMatrix, ref srcRect)",please give me a sample.

Thanks in advance.

[kyo]

Dear All,
I have created a simple C# project using the DrawToIXCPage method to generate thumbnails as your links told me to do.

The result is that the project can run smoothly,but no thumnail is displayed(maybe some coordinate is not correct).

I have a strong feeling that the destination page(IIXC_Page) maybe is rotated,and also I pass a incorrect PXC_Matrix to the DrawToIXCPage method.

I have upload the simple project which can work well.It will be very appreciated that if you can assist me to modify the code to implement my goal.

Thanks very much.

[Sasha - Tracker Dev Team]

Hello kyo,

In your case, the correct code would look like this:

Code: Select all

PDFXEdit.IIXC_Page iDestPage = ixcInst.Page_CreateEmpty((uint)page_pixel_W, (uint)page_pixel_H, IXC_PageFormat.PageFormat_8RGB, 0x00FFFF);
PDFXEdit.tagRECT destRect;
destRect.left = 0;
destRect.bottom = (int)iDestPage.Height;
destRect.right = (int)iDestPage.Width;
destRect.top = 0;

PDFXEdit.PXC_Matrix srcPageMatrix = srcPage.GetMatrix(PDFXEdit.PXC_BoxType.PBox_PageBox);
PDFXEdit.PXC_Rect srcRect = srcPage.get_Box(PDFXEdit.PXC_BoxType.PBox_PageBox);
auxInst.MathHelper.Rect_Transform(srcPageMatrix, ref srcRect);
PDFXEdit.PXC_Rect dRect;
dRect.left = destRect.left;
dRect.top = destRect.top;
dRect.right = destRect.right;
dRect.bottom = destRect.bottom;
PDFXEdit.PXC_Matrix destMatrix = auxInst.MathHelper.Matrix_RectToRect(srcRect, dRect);

destMatrix = auxInst.MathHelper.Matrix_Multiply(srcPageMatrix, destMatrix);

srcPage.DrawToIXCPage(iDestPage, ref destRect, ref destMatrix);

Cheers,
Alex

[vivekpatel]

Hello,

I want to do this by simple document file rather then pdf control, that you did in attached zip file.
so, it's possible??
if, yse than how??

[Sasha - Tracker Dev Team]

Hello vivekpatel,

Please provide detailed description of what you need only then I can assist further.

Cheers,
Alex