Re: [OT] scanned files are large in size
On Tue 01 Jan 2019 at 12:34:38 -0500, kamaraju kusumanchi wrote:
> A scanned document from Canon pixma mx870 printer is significantly
> larger compared to the same document scanned on a different scanner.
Which is...?
> When I look at both the images side by side on a PC, there is no
> visual difference between the two. I am trying to understand the
> underlying cause and fix it if possible.
You could mention which scanning software you used and what the
setting for the output file format was.
> As shown below, scanned_in_office.pdf is 332Kb, scanned_on_mx870.pdf is 1.7 Mb.
>
> % ls -al scanned_in_office.pdf scanned_on_mx870.pdf
> -rw-r--r-- 1 rajulocal rajulocal 331796 Jan 1 11:54 scanned_in_office.pdf
> -rw-r--r-- 1 rajulocal rajulocal 1775460 Jan 1 11:48 scanned_on_mx870.pdf
>
> Both are are scanned at 600 dpi. The only difference I see is in bpc,
> enc fields.
>
> % pdfimages -list scanned_in_office.pdf
> page num type width height color comp bpc enc interp object ID
> x-ppi y-ppi size ratio
> --------------------------------------------------------------------------------------------
> 1 0 image 5104 6600 gray 1 1 ccitt no 7 0
> 601 600 183K 4.5%
> 2 1 image 5104 6600 gray 1 1 ccitt no 14 0
> 601 600 138K 3.4%
>
> % pdfimages -list scanned_on_mx870.pdf
> page num type width height color comp bpc enc interp object ID
> x-ppi y-ppi size ratio
> --------------------------------------------------------------------------------------------
> 1 0 image 5100 6600 gray 1 8 jpeg no 8 0
> 600 600 1066K 3.2%
> 2 1 image 5100 6600 gray 1 8 jpeg no 14 0
> 600 600 665K 2.0%
>
> 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)?
Not at all; the printer has nothing to do with it. Printing is printing.
Scanning is scanning.
> 2) Is the difference in image sizes due to the bpc (1 vs. 8) or
> encoding (ccitt vs jped) fields?
Could be.
> 3) If yes, how to change them?
One file is in (I think) tiff format. The other isn't. You didn't scan
like and like from both devices.
--
Brian.
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