Re: Why does saves as JPG default to quality 85?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




* Ofnuts <ofnuts@xxxxxxxxxxx> [01-01-70 12:34]:
> On 03/23/2012 09:20 PM, Liam R E Quin wrote:
> >every time you load and
> >save a JPEG file the quality is reduced and information is lost.
> Not true... if nothing changes the algorithm is stable (decoded values get
> re-encoded to the same values). You lose quality if you recompute something
> different; changed settings, changed pixel values, changed 8x8 boundaries
> (image crop).

Well, it is true and very easily proven.

Open a jpg file and save it.  Then open the just saved file and save it
again at the save compression level.  Then do a diff or simply check the
file sizes.

-- 
(paka)Patrick Shanahan       Plainfield, Indiana, USA      HOG # US1244711
http://wahoo.no-ip.org        Photo Album: http://wahoo.no-ip.org/gallery2
http://en.opensuse.org                           openSUSE Community Member
Registered Linux User #207535                    @ http://linuxcounter.net
_______________________________________________
gimp-user-list mailing list
gimp-user-list@xxxxxxxxx
http://mail.gnome.org/mailman/listinfo/gimp-user-list


[Index of Archives]     [Gimp Announce]     [Gimp GUI]     [Gimp Images]     [GIMP Development]     [Video For Linux]     [Photos]     [Yosemite News]     [Yosemite Photos]     [gtk]     [KDE]     [Scanners]     [Gimp's Home]     [Gimp Docs]     [Gimp on Windows]     [Steve's Art]     [Webcams]     [Share Your Images]     [Script Fu]     [GIMP Software]     [GIMP Books]

  Follow Gimp on Twitter