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Re: [OT] scanned files are large in size




On Tue 01 Jan 2019 at 22:41:06 -0500, kamaraju kusumanchi wrote:

> On Tue, Jan 1, 2019 at 1:40 PM <tomas@xxxxxxxxxx> wrote:
> >
> > Yep. The one image is encoded as CCITT (aka Group 4, aka fax [1]), which is
> > passable for low res B&W images, but not that much for hi-res or color (or
> > gray scale). It compresses much worse than the other which is JPEG, which is
> > expressly made for hi-res and color (or grayscale) images.
> >
> > OTOH, CCITT is lossless and JPEG lossy ;-)
> >
> ok, thanks.
> 
> > > Questions:
> > > 1) Does the large file size have anything to do with the printer
> > > itself? Is there anything I can do (ex:- update the driver/firmware or
> > > something)?
> >
> > That depends on what is encoding the images: does the scanner itself
> > "make" the PDF? Or some software, computer-side?
> >
> 
> The scanner itself makes the pdf files.

I'm intrigued; I hadn't realised that conversion of the scanned image
for some vendors' devices took place on the device itself. How do you
know this happens? It is the frontend to SANE (xsane or scanimage, for
example) which I've always associated with image aquisition conversion.

-- 
Brian.