XnView Software

Hi,

I have been an nConvert user for many years and it's a great app, thanks!

I am trying to find a way of converting lots of documents scanned as single page JPG files into multi page TIF files without ending up with huge files. I can get the conversion to work fine but the best TIF compression I can get, whilst still retaining a good quality document, is around 6 times the size of the original JPG files.

The best results I get are using LZW (-c 2) but this gives me a 60MB TIF (124 pages) in comparison to the 9MB total size of the individual JPG files. I have tried reducing the dpi but this has little impact as the images are already only 150dpi. Using the -binary options result in much lower sizes but parts of the document become almost illegible and the overall quality is very poor.

Does anyone have any advice on how I can get these sizes down as with 1.2 million JPG files the resulting size increase with be huge?

Hoping someone can help.

Thanks

Ben

Do you have tried with JPEG compression?

Hi Pierre,

Thank you for the reply.

I have tried using the -c 8 option is this is what you mean:

C:\nconvert\nconvert -out tiff -o C:\nconvert\jpgtest.tif -multi -c 8 c:\nconvert\temp\*.jpg

This results in a much smaller file size than -c 2 but the image cannot be opened by any of the 5 tif viewers I have on my machine. A couple of the viewers report that the image is "damaged or corrupt".

I think this may be decause the -c 8 option is 24/32 bit dependent and the original JPG files only have a Bit Depth of 8. I tried using the -32bits option:

C:\nconvert\nconvert -out tiff -o C:\nconvert\jpgtest.tif -multi -32bits -c 8 c:\nconvert\temp\*.jpg

This allowed me to view the resulting tif but the file size was 1Gb!

Do you have any other ideas?

Many Thanks

Ben

Is it possible to send 2 original files to test?

Hi Pierre,

Not sure how to send via Forum so have emailed to webmaster. Hope this is ok(?)

Thanks

Ben