Scanned Files

[Arnold]

PDFX Viewer is for the most part pretty fast even on my old computer. It is an Intel Celeron 764 mhz, 512 mb of ram, windows xp sp3. Graphics are just on-board graphics using up to 8 mb of RAM I think. Certain scanned files that I receive are very slow though. I have extracted only 2 pages for you to see from a 7 page scanned file, as it is 4.5 mb! Is this my system or is there some other reason? Thank you.

[Chris - Tracker Supp]

Hi Arnold,

We have opened your files here and they opened fine, no unexpected or prolonged delays, so we suppose it must be your system. I suggest that you let some firends with higher spec machines try the files and see if they experience the same dealys as you have described. And please do get back to us with your findings.

Best Regards,
Chris

[Bhikkhu Pesala]

Its probably down to the slow processor and onboard graphics. The scans apparently use JBig compression, which may require some time to decompress.

On my system, which has a faster processor than yours, though is not fast by today's standards, and also onboard graphics, the file loads and zooms fast enough to be no problem at all.

Have you compared the performance in Adobe Reader? I cannot detect any difference with Adobe Reader 7. The performance in PDF-XChange is smoother IMO.

Foxit Reader asks me to download some extras before it can decode the images.

[Arnold]

I will compare with some other browsers, and see if there is a difference and post back the results. I get a lot of specifications sent to me and a good percentage of them are just scanned in. The ones that are not work beautifully. PDFX seems to be faster than Acrobat if I am looking at architectural drawings (22" x 40"), as I tried that. But not on these scanned in specifications. I will investigate some more. Thank you all. It sure is a .pdf world.

[Chris - Tracker Supp]

We'll see what you come back with

Cheers,
Chris

[Arnold]

I decided to try it out in a few viewers just for kicks - PDFX, Acrobat 6, and I downloaded Nitro 6 Professional, and Foxit. PDFX and Acrobat were similar, and seemed to render the pages and hold them in memory so that scrolling through the pages after the initial delay was good. PDFX seemed to render the pages in stages, and Acrobat put the whole page on screen, but it was fuzzy and took about 2 - 3 full seconds to sharpen up after that. After the first rendering/decompressing PDFX was smooth as silk when scrolling up and down through the document (7 pages). Nitro and Foxit were similar and were somewhat faster at rendering, but they did not seem to ever stop doing it. Whenever, I scrolled up and down through the document it would continue to re-render/decompress the image. No matter how many times I scrolled up and down. At no point did I get the smooth feel I got with PDFX after the first bit of slowness. It did appear as though the problem was my machine just trying to churn through what it needed to do to present the image onscreen. The interface of PDFX is way better than the others. I did not like the Nitro interface, I would go back to Acrobat first. Hope that all makes sense. Thanks.

[Tracker Supp-Stefan]

Hey Arnold,

Thank you for this comparison, as my machine is a bit faster and it is tircky to notice anything happen slowly here.

So what is the final conclusion is PDFXChange the fastest of them all?

Stefan

[Arnold]

Yes it is. Smoother and faster. I wish it was faster on some scanned pdf's. Some of them seem faster than others, I don't know why. But, I believe it is because of the slowness of my machine.


Update

Tried opening the file on a faster computer - Celeron 3.2 ghz, 896 mb of RAM. Video card ATI Radeon Express 200, 128 mb of RAM. Windows XP sp3. File is 7 pages, 4.41 mb, scanned into Acrobat 6 I think.

On this machine Acrobat 6 seems faster. When scrolling pages after opening the file, the whole page appears as described before, but it sharpens up quicker on this machine as would be expected.

PDFX continues to render pages in sections as you scroll down through the document, and seems about the same on this computer. Both programs again smooth when scrolling up and down once all pages are rendered onscreen.

[Chris - Tracker Supp]

Hi Arnold,

I believe it's like Bhikkhu mentioned, I converted them to jpg and back to pdf again and it was the same, it's barely noticable, on my machine, the first time you view a page as the image decompresses, but fine there after. Image files are like that especially compared to text based pdf's or the drawings you mentioned that are converted to pdf directlly. So I guess the improvements you saw on other machines are the improvements that you'd gain using a faster system.

I then printed the survey.pdf to our PDF-XChange 4 Print-Driver and changed the image compression to jpeg/zip. The file size increased about 650 KB but the image decompression was faster see if this is an improvement. If you have the PDF-XChange 4 Print drivers, try it with some other files that usually decompress slow for you you might find it an improvement. If you don't, you can download a trial copy from our website and try it out. The resulting pdfs will be watermarked but it will show you the load improvement. I've attached the survey3.zip containing the improved compression response for your interest.

http://www.docu-track.com/downloads/users/

Hope that helps,
Chris

[Arnold]

Thank you for taking the time to investigate. If they were all just 7 pages long it would not really matter much, but sometimes they are 90 pages or more. I sometimes get them in here with as much as 240 pages, but those ones to be regular pdf’s, not the scanned ones.

I have another scanned one sent to me by the same contractor that is 26 pages long and is only 4 meg. This one seems to have been scanned in grayscale with Acrobat 9 not 6. A third one I just looked at is color, 25 pages long, and is only 1.10 meg. That was scanned with a Canon scanner and Canon software. That one runs pretty smoothly. The one in grayscale is also faster than the first one we discussed, which is a color scan. Would the differences in how the scan was done, color, dpi, etc. have an effect on how the pdf renders? I don’t think info such as that shows up in the pdf itself. Once again, thank you for your time. I will try out your suggestion with PDF Xchange 4.

[Chris - Tracker Supp]

Hi Arnold,

Yes the way the original image was created and saved dictates the compression used. So when trying out the PDF-XChange 4 software. Once installed in your printers list, right click it and select printing preferences.

In the Compression Settings you'll see the different compression options you can change as per the Image types: High Color, Indexed Images, and Monochrome. Each has different compression algorithms to try based on the images you are working with.

Once your preferences are set for the corresponding pdf file, open it in the Viewer, chose File->Print and select the PDF-XChange 4 printer and it will prompt you to save the new PDF file, and create it using the compression option you've chosen.

Hope that helps,

Regards,
Chris

[Bhikkhu Pesala]

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