Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-22 Thread Raphaël Quinet
On Wed, 15 Aug 2007 10:20:48 -0400, [EMAIL PROTECTED] wrote:
 Quoting Robert L Krawitz [EMAIL PROTECTED]:
  The problem is that custom tables seems very confusing -- it sounds
  like the user's going to be asked to input something she knows nothing
  about.  One could argue that Use existing image quality settings [...]
 My only comment on this issue is that the term image is consistently  
 employed within the GIMP vocabulary to mean the in-memory copy of  
 the picture being edited [...]

I think that using the terms original image would avoid this problem.

We are basically left with two options:

1) Use custom quality settings
   - Hard to understand for most users
   - Technically correct description
   - No need to change the code; this is what we have now

2) Use quality settings from original image
   - Easier to understand for most users
   - Correct description for the most common usage scenario
   - Requires some small changes to the code
   - Breaks the string freeze before 2.4

It seems that going for (2) would be better for the users but would
annoy some translators.  But I got several requests to go for something
like option (2), so I would like to know if it is worth breaking the
string freeze.  Opinions?

-Raphaël

P.S.: please do not mention bikesheds.
___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-15 Thread Raphaël Quinet
On Mon, 13 Aug 2007 13:36:05 +0200, Raphaël Quinet [EMAIL PROTECTED] wrote:
 On Mon, 13 Aug 2007 07:10:30 -0400, Robert L Krawitz [EMAIL PROTECTED] 
 wrote:
  Would Use existing image quality settings be a better name for this?
 
 I considered naming this option Use original quality settings, but
 one thing that I forgot to mention in my previous messages is that
 it is possible to write a script or plug-in that attaches different
 quantization tables to any image.  [...]

Although I was a bit reluctant to do this, we could try to change the
name of this option to Use original quality settings or Use quality
settings from original image or something like that.  This would
require several changes in behavior explained below.  This new meaning
may not be appropriate if other quantization tables than the original
ones are attached to the image, but if we consider that usage to be an
exception, then maybe we can optimize for the common case if this
could make the option more understandable.  Anyway, if we want to
change that string, then we have to reach a consensus on that in the
next few hours and make sure that it will not change again until GIMP
2.4 is out.  We should be in string freeze now.

If we change the label, this also changes the meaning of the option
and this will require some changes to the code:

- Currently, Use custom quality settings is only available when the
  quantization tables are non-standard ones.  If the tables can be
  generated by the IJG JPEG library, then the option is grayed out
  because the user can get the same table with the existing quality
  slider (and that slider is already set to the right value if the
  quality of the original file is better than the user's default).  If
  that option is changed to mean I want the same settings as the
  original image instead of I want to use some non-standard tables,
  then that option should always be available even if the original
  image used standard quantization tables.

- Enabling that option should not only change the quality slider, but
  it should also change the choice of subsampling parameters, even if
  the chroma subsampling in the original image is not as good as the
  user's defaults (i.e., if the default is 1x1 and the original image
  used the lower quality 2x2 or 2x1).  This would ensure that all
  significant parameters from the original image are re-used when
  saving.  Note that it would be a one-way change: enabling the
  option Use original quality settings would change the subsampling
  parameters, but changing the subsampling parameters later would not
  disable the option (unlike what is done when the quality slider is
  moved).

- Optionally, the usage (or not) of optimized Huffman tables could be
  detected in the original image and re-used when saving.  I think
  that it would be better to leave it always enabled (always optimize)
  but if we want to be as close as possible to the original image,
  then we could disable the optimization if the original image was not
  optimized.

Implementing these changes would be easy (except for the last one,
maybe) and I know exactly what would have to be be changed so the code
itself is not an issue here.  But we should quickly decide what this
option should mean.  I like the current meaning (custom tables) but
some of you think that it would be easier to understand something
referring to the original quality settings.  If we can reach a quick
agreement on what is better (considering the differences explained
above) and if it is not too late for 2.4rc1, then maybe I could change
that option.

-Raphaël
___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-15 Thread Robert L Krawitz
   Date: Wed, 15 Aug 2007 10:25:54 +0200
   From: =?UTF-8?B?UmFwaGHDq2w=?= Quinet [EMAIL PROTECTED]

   On Mon, 13 Aug 2007 13:36:05 +0200, Raphaël Quinet [EMAIL PROTECTED] wrote:
On Mon, 13 Aug 2007 07:10:30 -0400, Robert L Krawitz [EMAIL PROTECTED] 
wrote:
 Would Use existing image quality settings be a better name for this?

I considered naming this option Use original quality settings, but
one thing that I forgot to mention in my previous messages is that
it is possible to write a script or plug-in that attaches different
quantization tables to any image.  [...]

   Although I was a bit reluctant to do this, we could try to change the
   name of this option to Use original quality settings or Use quality
   settings from original image or something like that.  This would
   require several changes in behavior explained below.  This new meaning
   may not be appropriate if other quantization tables than the original
   ones are attached to the image, but if we consider that usage to be an
   exception, then maybe we can optimize for the common case if this
   could make the option more understandable.  Anyway, if we want to
   change that string, then we have to reach a consensus on that in the
   next few hours and make sure that it will not change again until GIMP
   2.4 is out.  We should be in string freeze now.

...

   Implementing these changes would be easy (except for the last one,
   maybe) and I know exactly what would have to be be changed so the code
   itself is not an issue here.  But we should quickly decide what this
   option should mean.  I like the current meaning (custom tables) but
   some of you think that it would be easier to understand something
   referring to the original quality settings.  If we can reach a quick
   agreement on what is better (considering the differences explained
   above) and if it is not too late for 2.4rc1, then maybe I could change
   that option.

The problem is that custom tables seems very confusing -- it sounds
like the user's going to be asked to input something she knows nothing
about.  One could argue that Use existing image quality settings
means the same thing as Use quality settings currently attached to
the image, and then nothing about the behavior would have to change.
___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-15 Thread saulgoode
Quoting Robert L Krawitz [EMAIL PROTECTED]:

 The problem is that custom tables seems very confusing -- it sounds
 like the user's going to be asked to input something she knows nothing
 about.  One could argue that Use existing image quality settings
 means the same thing as Use quality settings currently attached to
 the image, and then nothing about the behavior would have to change.

My only comment on this issue is that the term image is consistently  
employed within the GIMP vocabulary to mean the in-memory copy of  
the picture being edited (when an image is duplicated, scaled, changed  
mode, etc., the file is not affected). It would be confusing to use  
the term image to describe a file attribute that is basically  
independent of the in-memory data.


___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-13 Thread Sven Neumann
Hi Raphael,

On Sun, 2007-08-12 at 23:44 +0200, Raphaël Quinet wrote:

 Since Friday, I added a new option to the JPEG save dialog: Use
 custom quality settings.  If some quantization tables were attached
 to the image when it was loaded, then this option allows you to use
 them instead of the standard ones (different quantization tables are
 generated by the IJG JPEG library for each quality level).

Why do we need an option in the GUI for this? If there are quantization
tables attached and the user doesn't change the save quality, then just
use them. Or is there a real disadvantage in doing that? To me it looks
like you are asking the user a question that she is unlikely going to
understand. And you are forcing the user to make a decision that you can
better do for her.


Sven


___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-13 Thread Raphaël Quinet
On Mon, 13 Aug 2007 09:22:58 +0200, Sven Neumann [EMAIL PROTECTED] wrote:
 On Sun, 2007-08-12 at 23:44 +0200, Raphaël Quinet wrote:
  Since Friday, I added a new option to the JPEG save dialog: Use
  custom quality settings.  If some quantization tables were attached
  to the image when it was loaded, then this option allows you to use
  them instead of the standard ones (different quantization tables are
  generated by the IJG JPEG library for each quality level).
 
 Why do we need an option in the GUI for this? If there are quantization
 tables attached and the user doesn't change the save quality, then just
 use them. Or is there a real disadvantage in doing that? To me it looks
 like you are asking the user a question that she is unlikely going to
 understand. And you are forcing the user to make a decision that you can
 better do for her.

I think that this option is still useful.  Maybe not for disabling it
when it is enabled, but for enabling it when it is not enabled
automatically.  It is usually better to use the custom quantization
tables if they are better than your default quality settings.  But
if they are not better, then it is nice to give a choice to the user.

If the quantization tables found in the original file are not better
than your default quality settings, then the option Use custom
quality settings will be available but not enabled.  This ensures
that you always get at least the minimum quality specified in your
defaults.  If you did not make major changes to the image and you want
to save it using the same quality as the original, then you can do it
by enabling this option.

-Raphaël
___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-13 Thread Alexander Rabtchevich
Why don't add  such a wonderful floating tip with a short description of 
the switch and not to revoke the possibility from a user?

Raphaël Quinet wrote:
 I think that this option is still useful.  Maybe not for disabling it
 when it is enabled, but for enabling it when it is not enabled
 automatically.  It is usually better to use the custom quantization
 tables if they are better than your default quality settings.  But
 if they are not better, then it is nice to give a choice to the user.


   


-- 
With respect
Alexander Rabtchevich

___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-13 Thread Raphaël Quinet
On Mon, 13 Aug 2007 11:16:15 +0300, Alexander Rabtchevich [EMAIL PROTECTED] 
wrote:
 Why don't add  such a wonderful floating tip with a short description of 
 the switch and not to revoke the possibility from a user?

This is already done.  There is a tooltip associated with that option
and it explains what it can be used for.  Just try it an see for
yourself...

Sven is right to be concerned about the number of options in the JPEG
save dialog.  But as I explained in my previous message, this one is
useful so that is why I added it.  Besides the option Force baseline
JPEG that I removed last Friday, there are other options that could
be removed in the future:
- the choice of DCT method (integer, fast but less accurate integer,
  or floating-point) because the speed differences are not significant
  anymore,
- the ability to add restart markers because unreliable channels are
  much less common nowadays,
- the smoothing option because this can also be performed by the usual
  blur filters.
All these options could still be available through the PDB interface
for those who really miss them, but otherwise I think that they should
be removed from the advanced options soon after GIMP 2.4 is released.
It will then be time to think about redesigning the JPEG save dialog
from scratch.

As I mentioned earlier, I would like to simplify that dialog and only
have a dozen presets for the quality settings instead of having the
101 values in the quality slider plus the choice of chroma subsampling
in the advanced options.  Picking one of these presets would select
the corresponding quality level (quantization tables) and the most
appropriate chroma subsampling.  These may still be available in the
advanced options, but most users would never have to worry about them.
I am not sure if the best way to make a choice among the dozen presets
would be a set of radio buttons, a slider with discrete values or a
combo box, but this is something that we can discuss later when we
redesign that window.

-Raphaël
___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-13 Thread Alexander Rabtchevich
Raphaël, I would object to removal of DCT method settings switch. Make a 
simple but clear test case - open any file from RAW and save it with 
100% quality, 1x1,1x1,1x1 subsampling and integer vs float DCT method. 
Then open two resulted files as 2 layers, subtract, flatten and look at 
the histogram. If set upper slider to 10 and medium to 5, you will see  
rather significant difference between two files.
The reason is to make user possible to obtain  as much quality jpg as 
possible if he wishes so.  Note, that the majority  of photo labs only 
accepts jpgs. Also if one prefer storing his images in loss format, but 
as qualitatively as  possibly why prevent him from doing so?

Raphaël Quinet wrote:
 Sven is right to be concerned about the number of options in the JPEG
 save dialog.  But as I explained in my previous message, this one is
 useful so that is why I added it.  Besides the option Force baseline
 JPEG that I removed last Friday, there are other options that could
 be removed in the future:
 - the choice of DCT method (integer, fast but less accurate integer,
   or floating-point) because the speed differences are not significant
   anymore,


-- 
With respect
Alexander Rabtchevich

___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-13 Thread Robert L Krawitz
   Date: Mon, 13 Aug 2007 10:08:27 +0200
   From: =?UTF-8?B?UmFwaGHDq2w=?= Quinet [EMAIL PROTECTED]

   On Mon, 13 Aug 2007 09:22:58 +0200, Sven Neumann [EMAIL PROTECTED] wrote:
On Sun, 2007-08-12 at 23:44 +0200, Raphaël Quinet wrote:
 Since Friday, I added a new option to the JPEG save dialog: Use
 custom quality settings.  If some quantization tables were attached
 to the image when it was loaded, then this option allows you to use
 them instead of the standard ones (different quantization tables are
 generated by the IJG JPEG library for each quality level).

Why do we need an option in the GUI for this? If there are quantization
tables attached and the user doesn't change the save quality, then just
use them. Or is there a real disadvantage in doing that? To me it looks
like you are asking the user a question that she is unlikely going to
understand. And you are forcing the user to make a decision that you can
better do for her.

   I think that this option is still useful.  Maybe not for disabling it
   when it is enabled, but for enabling it when it is not enabled
   automatically.  It is usually better to use the custom quantization
   tables if they are better than your default quality settings.  But
   if they are not better, then it is nice to give a choice to the user.

   If the quantization tables found in the original file are not better
   than your default quality settings, then the option Use custom
   quality settings will be available but not enabled.  This ensures
   that you always get at least the minimum quality specified in your
   defaults.  If you did not make major changes to the image and you want
   to save it using the same quality as the original, then you can do it
   by enabling this option.

Would Use existing image quality settings be a better name for this?
___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-13 Thread Liam R E Quin

On Mon, 2007-08-13 at 11:25 +0200, Raphaël Quinet wrote:
[...]
 - the smoothing option because this can also be performed by the usual
   blur filters.

Actually no, I don't think it can :-)

The smoothing seems to reduce jpeg artifacts quite noticeably; it
appears as if it's done after decompression... although I might
easily be mistaken.

Liam

-- 
Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
Pictures from old books: http://fromoldbooks.org/
Ankh: irc.sorcery.net irc.gnome.org www.advogato.org

___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer


Re: [Gimp-developer] New option Use custom quality settings for JPEG files

2007-08-13 Thread Liam R E Quin
On Mon, 2007-08-13 at 13:36 +0200, Raphaël Quinet wrote:
 [...]

   Considering
 that the quantization tables attached to an image would not always
 be the original ones, I decided to write custom instead of
 original for the label of that option.  It is not perfect, but I
 have not been able to find a better description..
It sounds like Use quantization tables that are embedded in the image
is what you mean?

Liam

-- 
Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
Pictures from old books: http://fromoldbooks.org/
Ankh: irc.sorcery.net irc.gnome.org www.advogato.org

___
Gimp-developer mailing list
Gimp-developer@lists.XCF.Berkeley.EDU
https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer