Question: I have a PDF of scanned book, the images are in JBIG2 format (B&W). I'd like to convert this to a vector PDF, which I can do easily by extracting the images and converting them to PDF vector graphics instructions.The reason for this is that I want the PDF to display smoothly and quickly on an eBook reader device, such as a Kindle. With JBIG2 it is not doing this very well. Depending on the settings, the Kindle can't display the PDF, and even with that fixed it takes a long time to render each page. With a vector PDF the performance is much better, and the rendering very crisp.The problem is that the resulting PDF is gigantic in file size. Even with the streams compressed to the max it is 300KB per page (original JBIG2 images were 30KB per page).
Is there any tool on VeryPDF I can optimize the vector graphics so that the file size is much less?
Answer: The question is a little equivocal as compressing PDF and optimizing PDF are totally different. When optimize PDF, software will regroup the elements of a PDF file, and make all the information for displaying the first page located at the beginning of the file. But when compressing PDF, software will reduce the size of images in a PDF file by downsampling and compressing. If you need to compress PDF, software VeryPDF PDF Compressor is a good choice. But for optimizing PDF, software VeryPDF PDF Linearization Optimizer Command Line is a good application. In the following part, I will take optimizing PDF for example. I guess this tool will be much more helpful when you upload PDF eBook online and then display the PDF quickly and easily.
Step 1. Free download PDF Linearization Optimizer Command Line
- As its name shows, this is command line version software, when download finishes, there will be a zip file. Please extract it to some folder then you can find the executable file, help documents and others.
- And please note, after optimizing PDF, file size maybe will be larger before linearization is because that additional information needs to be added into the PDF file but the displaying speed will be much faster.
Step 2. Optimize PDF
- When you use this software, please refer to the usage and example of this software:
- Usage: pdfopt [options] <pdf-file> [<out-pdf>]
- When you need to optimize PDF, please refer to the following command line templates.
pdfopt.exe C:\in.pdf C:\out.pdf
pdfopt.exe C:\in\*.pdf C:\out\*.pdf
for %F in (D:\test\*.pdf) do "pdfopt.exe" "%F" "%~dpnF-out.pdf"
for /r D:\test %F in (*.pdf) do "pdfopt.exe" "%F" "%~dpnF-out.pdf"
This software provides four modes to optimize PDF file, please have a check.
mode <int> : select different modes to Linearize PDF file
-mode 0: Linearize PDF file automatically
-mode 1: mode 1 to Linearize PDF file
-mode 2: mode 2 to Linearize PDF file
-mode 3: mode 3 to Linearize PDF file
-mode 4: mode 4 to Linearize PDF file
And this software can be used to optimize all the PDF file no matter image based or text based, so it will be helpful too to optimize vector PDF. But this software can not be used to convert scanned PDF to searchable PDF file. During the using, if you have any question, please contact us as soon as possible.