Quality of the PDF image

Hi Sir

My name is Alex and I am using using lead toold 14.5 for creating the PDFfiles..  I scan a page as black and white pdf with jpeg YUV4:1:1 compression and 24bits/pixel with a quality factor of 2.  I feel quality of the image is not so good .(especually the lines are not clear and straight)

But If I scan through paperport scan 11.0 software by selecting file type as pdf and blackwhite I get a much better quality picture.And even the size is smaller...( since i see lead dll in their folder I assume paperport is also using leadtools internally)  

Could you please help me in doing the correct setting to get good quality  image with lesser size  ?

Do I have to write soem code to clean the image after scanning?It would be great if somebody can give me some code snippet..

Thanks in advance

Alex Jo Crispin

 

 

 

 

 

Try the TIFF CCITT Group4 image format rather than JPEG 4:1:1.  Since you are only scanning at black and white, you only need the image to be 1bpp rather than 24.  Additionally, JPEG 4:1:1 degrades the image data, even with a low QFactor like 2.  If you must use JPEG for whatever reason, then you should use 8 bpp and save it as a lossless JPEG if you don't want the image data to degrade. 

Hi Greg

Thankyou for the quick response. My requirement is to do multipage scanning with pdf file as output.My clients mostly do black and white scanning but color scanning is not rare. when I use raspdf without jpeg compression size became too big.

could you please suggest me best settings for doing a multipage pdf with lowest size and highest quality?

thanks

Alex

"RasPdf" is an uncompressed PDF format and is most likely why you are not happy with the file sizes.  If you take a look in your LEADTOOLS for .NET Class Library help file at the article "File Formats: Portable Document Format (PDF)" you will see each kind of PDF file LEADTOOLS can save out.

For color and best quality I would suggest RasPdfJpeg with 24bpp because this uses 4:4:4 and won't degrade your data.

For black and white, use RasPdfG4, because this is a 1bpp format and uses the CCITT Group 4 compression algorithm I mentioned earlier.