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XnView uses same JPEG encoder as GIMP ?

Posted: Sun Oct 07, 2007 10:57 pm
by spacemarine
When saving JPEGs with exactly the same settings from XnView and from
GIMP, the filesize is identical to the last byte.

Do XnView and GIMP use the same JPEG encoder library ?

If yes, then an option to select the DCT method when saving JPEGs
(as in GIMP) would be nice. Or, just use Floating-Point instead of Integer by
default, as speed is less and less an issue with PCs becoming faster and
faster.

Re: XnView uses same JPEG encoder as GIMP ?

Posted: Mon Oct 08, 2007 3:00 am
by XnTriq
spacemarine wrote:Do XnView and GIMP use the same JPEG encoder library ?
Info » About...: “The JPEG functions are based in part on the work of the Independent JPEG group”
spacemarine wrote:If yes, then an option to select the DCT method when saving JPEGs
(as in GIMP) would be nice. Or, just use Floating-Point instead of Integer by
default, as speed is less and less an issue with PCs becoming faster and
faster.
You already have it: Go to File » Export... » JPEG » DCT Method (Slow, Fast, Float).
It would be nice though if we had the same settings in Tools » Options... » General » Read/Write » Write » JPEG, too.

Posted: Mon Oct 08, 2007 3:27 pm
by spacemarine
Thx.

Yes, the DCT method should be selectable in the JPEG writing
options, too.


As the necessary code is already in the program, adding
the same dropdown box there should be a piece of cake :P

Oh, and "Smoothing Factor" could also be there (I dont use it,
but for the sake of consistency and completensess).

I would strongly recommend to make Float the new default,
as speed is no issue on todays PCs IMHO.

I would also recommend to make the descriptions a little more
user-friendly:

Fast --> Fast (worst but fastest)
Slow --> Slow
Float --> Float (best but slowest)

The same goes for Subsampling:

2x2,1x1,1x1 ----> 2x2,1x1,1x1 (default)
2x1,1x1,1x1 (4:2:2) ----> 2x1,1x1,1x1 (4:2:2)
1x1,1x1,1x1 ----> 1x1,1x1,1x1 (best quality)

What do you think ?

Posted: Mon Oct 08, 2007 6:08 pm
by Drahken
I prefer to use export myself, so that I can see the results of a given setting before actually using it & thus find the best settings for each image.

Posted: Mon Oct 08, 2007 11:02 pm
by spacemarine
My point is, the settings are all there when you select "export..."
... thats fine ;)

For the sake of consistency, they should also be in the Write--->JPEG
options.... so that you could also set what you want to be used
when you use the "save" or "save as" commands.

Again, the necessary code already seems to be in the program, so adding
these settings to the "general" Write--->JPEG options should be really, really
easy.