How does digiKam do raw conversions for the slide shows ?

[Linuxguy123]

I shot 600 raw images at a wedding this past weekend.  

I downloaded them into digiKam, tagged ~ 200 of the best and ran them in
the digiKam slide show for the gift opening the next day.  They looked
awesome.  Everyone was very pleased.

Yesterday I tried converting some of the same raw files to jpgs using
the tools in digiKam.  They didn't come out nearly as nice, due to
issues with white balance settings, exposure, etc.

How does digiKam generate the images for the raw files it displays in
the slide shows ?   How could I easily generate jpegs that look as good
as the images in the slideshow ?

Thanks

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[Mark Greenwood-2]

On Wednesday 23 Dec 2009 16:59:45 Linuxguy123 wrote:

> I shot 600 raw images at a wedding this past weekend.  
>
> I downloaded them into digiKam, tagged ~ 200 of the best and ran them in
> the digiKam slide show for the gift opening the next day.  They looked
> awesome.  Everyone was very pleased.
>
> Yesterday I tried converting some of the same raw files to jpgs using
> the tools in digiKam.  They didn't come out nearly as nice, due to
> issues with white balance settings, exposure, etc.
>
> How does digiKam generate the images for the raw files it displays in
> the slide shows ?   How could I easily generate jpegs that look as good
> as the images in the slideshow ?
>

I would assume that for the slideshow Digikam is using the embedded JPEG data from the RAW file and not the RAW data. You can extract the embedded JPEG using exiftool (though I forget how, try googling it) but that really defeats the object of using RAW. When you use RAW you are expected to do all the white balance etc adjustments yourself. The embedded JPEG has the camera's built-in adjustments already applied. If you're going to use the embedded JPEG you may as well just shoot JPEG in the first place.

There's no "easy" way to get good results from RAW, you need to put in the effort to 'develop' each shot yourself. With practice you'll soon be getting *better* results than the images in the slideshow.

However, all that said, I've found that the tools in Digikam sometimes don't cope very well with RAW files - you need accurate icc colour profiles for your camera, for one thing. Most people seem to like ufraw for RAW processing, and it does seem to give more "accurate" results than Digikam does.

Mark

> Thanks
>
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[Gilles Caulier-4]

2009/12/23 Mark Greenwood <[hidden email]>:

> On Wednesday 23 Dec 2009 16:59:45 Linuxguy123 wrote:
>> I shot 600 raw images at a wedding this past weekend.
>>
>> I downloaded them into digiKam, tagged ~ 200 of the best and ran them in
>> the digiKam slide show for the gift opening the next day.  They looked
>> awesome.  Everyone was very pleased.
>>
>> Yesterday I tried converting some of the same raw files to jpgs using
>> the tools in digiKam.  They didn't come out nearly as nice, due to
>> issues with white balance settings, exposure, etc.
>>
>> How does digiKam generate the images for the raw files it displays in
>> the slide shows ?   How could I easily generate jpegs that look as good
>> as the images in the slideshow ?
>>
>
> I would assume that for the slideshow Digikam is using the embedded JPEG data from the RAW file and not the RAW data. You can extract the embedded JPEG using exiftool (though I forget how, try googling it) but that really defeats the object of using RAW. When you use RAW you are expected to do all the white balance etc adjustments yourself. The embedded JPEG has the camera's built-in adjustments already applied. If you're going to use the embedded JPEG you may as well just shoot JPEG in the first place.

Yes, it use JPEG preview. Fast and usefull...

>
> There's no "easy" way to get good results from RAW, you need to put in the effort to 'develop' each shot yourself. With practice you'll soon be getting *better* results than the images in the slideshow.

and it's long to decode.

>
> However, all that said, I've found that the tools in Digikam sometimes don't cope very well with RAW files - you need accurate icc colour profiles for your camera, for one thing. Most people seem to like ufraw for RAW processing, and it does seem to give more "accurate" results than Digikam does.
>

I don't use ICC and i always shot in RAW (minolta). Results are fine
with a some adjustement (saturation). I use auto gamma and 16 bits
color depth of course.

I never use UFRAW : too complicated for me... and GTK (:=)))

Gilles Caulier
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[Linuxguy123]

On Wed, 2009-12-23 at 18:14 +0100, Gilles Caulier wrote:

> 2009/12/23 Mark Greenwood <[hidden email]>:
> > On Wednesday 23 Dec 2009 16:59:45 Linuxguy123 wrote:
> >>
> >> How does digiKam generate the images for the raw files it displays in
> >> the slide shows ?   How could I easily generate jpegs that look as good
> >> as the images in the slideshow ?
> >>
> >
> > I would assume that for the slideshow Digikam is using the embedded
> JPEG data from the RAW file and not the RAW data. You can extract the
> embedded JPEG using exiftool (though I forget how, try googling it)

Thanks for the tip.

>  but that really defeats the object of using RAW. When you use RAW you
> are expected to do all the white balance etc adjustments yourself. The
> embedded JPEG has the camera's built-in adjustments already applied.
> If you're going to use the embedded JPEG you may as well just shoot
> JPEG in the first place.

Thanks for the explanation about raws.  I never would have known that
from shooting over 20,000 of them and converting them to jpegs.

> Yes, it use JPEG preview. Fast and usefull...

Are you serious/ sure this is the case ?  I always thought the preview
jpegs were thumbnails.  I displayed the slideshow images on a 52" LCD TV
at 1920x1080.  There was no way they were thumbnails.

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[Mark Greenwood-2]

On Wednesday 23 Dec 2009 17:14:29 Gilles Caulier wrote:

> 2009/12/23 Mark Greenwood <[hidden email]>:
> > On Wednesday 23 Dec 2009 16:59:45 Linuxguy123 wrote:
> >> I shot 600 raw images at a wedding this past weekend.
> >>
> >> I downloaded them into digiKam, tagged ~ 200 of the best and ran them in
> >> the digiKam slide show for the gift opening the next day.  They looked
> >> awesome.  Everyone was very pleased.
> >>
> >> Yesterday I tried converting some of the same raw files to jpgs using
> >> the tools in digiKam.  They didn't come out nearly as nice, due to
> >> issues with white balance settings, exposure, etc.
> >>
> >> How does digiKam generate the images for the raw files it displays in
> >> the slide shows ?   How could I easily generate jpegs that look as good
> >> as the images in the slideshow ?
> >>
> >
> > I would assume that for the slideshow Digikam is using the embedded JPEG data from the RAW file and not the RAW data. You can extract the embedded JPEG using exiftool (though I forget how, try googling it) but that really defeats the object of using RAW. When you use RAW you are expected to do all the white balance etc adjustments yourself. The embedded JPEG has the camera's built-in adjustments already applied. If you're going to use the embedded JPEG you may as well just shoot JPEG in the first place.
>
> Yes, it use JPEG preview. Fast and usefull...
>
> >
> > There's no "easy" way to get good results from RAW, you need to put in the effort to 'develop' each shot yourself. With practice you'll soon be getting *better* results than the images in the slideshow.
>
> and it's long to decode.
>
> >
> > However, all that said, I've found that the tools in Digikam sometimes don't cope very well with RAW files - you need accurate icc colour profiles for your camera, for one thing. Most people seem to like ufraw for RAW processing, and it does seem to give more "accurate" results than Digikam does.
> >
>
> I don't use ICC and i always shot in RAW (minolta). Results are fine
> with a some adjustement (saturation). I use auto gamma and 16 bits
> color depth of course.
>

You have just filled in the missing piece of the puzzle for me I think... so I don't need an icc profile for my camera even if I use RAW? The RAW import tool somehow knows how to interpret the colour information? If that is the case then I think I now understand why I can't seem to get the results I expect when I'm using colour management. I think I actually don't need it at all.

Mark

> I never use UFRAW : too complicated for me... and GTK (:=)))
>
> Gilles Caulier
> _______________________________________________
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[Martin (KDE)]

Am Mittwoch, 23. Dezember 2009 schrieb Mark Greenwood:

> On Wednesday 23 Dec 2009 17:14:29 Gilles Caulier wrote:
> > 2009/12/23 Mark Greenwood <[hidden email]>:
> > > On Wednesday 23 Dec 2009 16:59:45 Linuxguy123 wrote:
> > >> I shot 600 raw images at a wedding this past weekend.
> > >>
> > >> I downloaded them into digiKam, tagged ~ 200 of the best and
> > >> ran them in the digiKam slide show for the gift opening the
> > >> next day.  They looked awesome.  Everyone was very pleased.
> > >>
> > >> Yesterday I tried converting some of the same raw files to
> > >> jpgs using the tools in digiKam.  They didn't come out nearly
> > >> as nice, due to issues with white balance settings, exposure,
> > >> etc.
> > >>
> > >> How does digiKam generate the images for the raw files it
> > >> displays in the slide shows ?   How could I easily generate
> > >> jpegs that look as good as the images in the slideshow ?
> > >
> > > I would assume that for the slideshow Digikam is using the
> > > embedded JPEG data from the RAW file and not the RAW data. You
> > > can extract the embedded JPEG using exiftool (though I forget
> > > how, try googling it) but that really defeats the object of
> > > using RAW. When you use RAW you are expected to do all the
> > > white balance etc adjustments yourself. The embedded JPEG has
> > > the camera's built-in adjustments already applied. If you're
> > > going to use the embedded JPEG you may as well just shoot JPEG
> > > in the first place.
> >
> > Yes, it use JPEG preview. Fast and usefull...
> >
> > > There's no "easy" way to get good results from RAW, you need to
> > > put in the effort to 'develop' each shot yourself. With
> > > practice you'll soon be getting *better* results than the
> > > images in the slideshow.
> >
> > and it's long to decode.
> >
> > > However, all that said, I've found that the tools in Digikam
> > > sometimes don't cope very well with RAW files - you need
> > > accurate icc colour profiles for your camera, for one thing.
> > > Most people seem to like ufraw for RAW processing, and it does
> > > seem to give more "accurate" results than Digikam does.
> >
> > I don't use ICC and i always shot in RAW (minolta). Results are
> > fine with a some adjustement (saturation). I use auto gamma and
> > 16 bits color depth of course.
>
> You have just filled in the missing piece of the puzzle for me I
>  think... so I don't need an icc profile for my camera even if I
>  use RAW? The RAW import tool somehow knows how to interpret the
>  colour information? If that is the case then I think I now
>  understand why I can't seem to get the results I expect when I'm
>  using colour management. I think I actually don't need it at all.

Hallo Mark

You don't need colour management to develop raw files. digiKam (and
all others raw converter) uses a default colour pattern if there is no
icc one available. The difference is mostly marginal. The advantage:
you don't have to fight the colour management battle, the
disadvantage: You loose some parts of colour control.

Martin

>
> Mark
>
> > I never use UFRAW : too complicated for me... and GTK (:=)))
> >
> > Gilles Caulier
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[Gilles Caulier-4]

2009/12/23 Linuxguy123 <[hidden email]>:

> On Wed, 2009-12-23 at 18:14 +0100, Gilles Caulier wrote:
>> 2009/12/23 Mark Greenwood <[hidden email]>:
>> > On Wednesday 23 Dec 2009 16:59:45 Linuxguy123 wrote:
>> >>
>> >> How does digiKam generate the images for the raw files it displays in
>> >> the slide shows ?   How could I easily generate jpegs that look as good
>> >> as the images in the slideshow ?
>> >>
>> >
>> > I would assume that for the slideshow Digikam is using the embedded
>> JPEG data from the RAW file and not the RAW data. You can extract the
>> embedded JPEG using exiftool (though I forget how, try googling it)
>
> Thanks for the tip.
>
>>  but that really defeats the object of using RAW. When you use RAW you
>> are expected to do all the white balance etc adjustments yourself. The
>> embedded JPEG has the camera's built-in adjustments already applied.
>> If you're going to use the embedded JPEG you may as well just shoot
>> JPEG in the first place.
>
> Thanks for the explanation about raws.  I never would have known that
> from shooting over 20,000 of them and converting them to jpegs.
>
>> Yes, it use JPEG preview. Fast and usefull...
>
> Are you serious/ sure this is the case ?  I always thought the preview
> jpegs were thumbnails.  I displayed the slideshow images on a 52" LCD TV
> at 1920x1080.  There was no way they were thumbnails.
>

YES. I'm serious !

RAW are containers. camera record a reduced version (and somethime the
full version) of JPEG image processed at the same time than RAW file.
Why ? to reder quicly the image on screen device and TV of course.

This is why preview in digiKam sound always better (in the first
approach) than the decoded RAW : all the algorithm from camera are
processed there...

This is not the case of RAW. You need to reproduce the camera job. And
as each camera maker and model use different algorithm, it's a worse !

I'm waiting JPEGXR from M$ encluded in camera to save my image using
waveltes compression and 16 bits color depth support. Bye bye RAW and
JPEG !
 Note : there is no others alternative than JPEGXR from M$, and
especially in open source, excepted PGF format, but promotion of this
do not exist...

Gilles Caulier


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[Milan Knížek]

Linuxguy123 píše v St 23. 12. 2009 v 10:25 -0700:
> > Yes, it use JPEG preview. Fast and usefull...
>
> Are you serious/ sure this is the case ?  I always thought the preview
> jpegs were thumbnails.  I displayed the slideshow images on a 52" LCD TV
> at 1920x1080.  There was no way they were thumbnails.

JPEG preview may not be the same as JPEG thumbnail in general meaning.

E.g. Canon EOS 5D MII stores a small resolution JPEG, full resolution
JPEG and raw data in the CR2 files. The full resolution JPEG is kind of
equal to the JPEG that camera produces (if raw is not used), but
possibly with lower JPEG quality settings.

Use

$ exiv2 -pp image.cr2
Preview 1: image/jpeg, 160x120 pixels, 11197 bytes
Preview 2: image/jpeg, 5616x3744 pixels, 1127852 bytes

to find out and

$ exiv2 -ep1,2 image.cr2

to actually extract the first and the second preview JPEG at the same
time. (This is not conversion from RAW!)

Exiftool may do the same job, read the man page...

Regards,

Milan Knizek
knizek (dot) confy (at) volny (dot) cz
http://www.milan-knizek.net - About linux and photography (Czech
language only)

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[Mark Greenwood-2]

On Wednesday 23 Dec 2009 17:25:43 Linuxguy123 wrote:

> On Wed, 2009-12-23 at 18:14 +0100, Gilles Caulier wrote:
> > 2009/12/23 Mark Greenwood <[hidden email]>:
> > > On Wednesday 23 Dec 2009 16:59:45 Linuxguy123 wrote:
> > >>
> > >> How does digiKam generate the images for the raw files it displays in
> > >> the slide shows ?   How could I easily generate jpegs that look as good
> > >> as the images in the slideshow ?
> > >>
> > >
> > > I would assume that for the slideshow Digikam is using the embedded
> > JPEG data from the RAW file and not the RAW data. You can extract the
> > embedded JPEG using exiftool (though I forget how, try googling it)
>
> Thanks for the tip.
>
> >  but that really defeats the object of using RAW. When you use RAW you
> > are expected to do all the white balance etc adjustments yourself. The
> > embedded JPEG has the camera's built-in adjustments already applied.
> > If you're going to use the embedded JPEG you may as well just shoot
> > JPEG in the first place.
>
> Thanks for the explanation about raws.  I never would have known that
> from shooting over 20,000 of them and converting them to jpegs.

There's no need for sarcasm. I was only trying to help.

>
> > Yes, it use JPEG preview. Fast and usefull...
>
> Are you serious/ sure this is the case ?  I always thought the preview
> jpegs were thumbnails.  I displayed the slideshow images on a 52" LCD TV
> at 1920x1080.  There was no way they were thumbnails.
>
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users
>

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[Gilles Caulier-4]

As Milan said, RAW are containers, and can include more than one
preview JPEG, dedicated for different use...

Gilles Caulier


2009/12/23 Milan Knížek <[hidden email]>:

> Linuxguy123 píše v St 23. 12. 2009 v 10:25 -0700:
>> > Yes, it use JPEG preview. Fast and usefull...
>>
>> Are you serious/ sure this is the case ?  I always thought the preview
>> jpegs were thumbnails.  I displayed the slideshow images on a 52" LCD TV
>> at 1920x1080.  There was no way they were thumbnails.
>
> JPEG preview may not be the same as JPEG thumbnail in general meaning.
>
> E.g. Canon EOS 5D MII stores a small resolution JPEG, full resolution
> JPEG and raw data in the CR2 files. The full resolution JPEG is kind of
> equal to the JPEG that camera produces (if raw is not used), but
> possibly with lower JPEG quality settings.
>
> Use
>
> $ exiv2 -pp image.cr2
> Preview 1: image/jpeg, 160x120 pixels, 11197 bytes
> Preview 2: image/jpeg, 5616x3744 pixels, 1127852 bytes
>
> to find out and
>
> $ exiv2 -ep1,2 image.cr2
>
> to actually extract the first and the second preview JPEG at the same
> time. (This is not conversion from RAW!)
>
> Exiftool may do the same job, read the man page...
>
> Regards,
>
> Milan Knizek
> knizek (dot) confy (at) volny (dot) cz
> http://www.milan-knizek.net - About linux and photography (Czech
> language only)
>
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users
>

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[Adam-268]

I think canon stores 3 or 4 of them. The TIFF is actually a lossless compressed jpg.


----- Original Message ----

> From: Gilles Caulier <[hidden email]>
> To: digiKam - Home Manage your photographs as a professional with the power of open source <[hidden email]>
> Sent: Wed, December 23, 2009 1:11:29 PM
> Subject: Re: [Digikam-users] How does digiKam do raw conversions for the slide shows ?
>
> As Milan said, RAW are containers, and can include more than one
> preview JPEG, dedicated for different use...
>
> Gilles Caulier
>
>
> 2009/12/23 Milan Knížek :
> > Linuxguy123 píše v St 23. 12. 2009 v 10:25 -0700:
> >> > Yes, it use JPEG preview. Fast and usefull...
> >>
> >> Are you serious/ sure this is the case ?  I always thought the preview
> >> jpegs were thumbnails.  I displayed the slideshow images on a 52" LCD TV
> >> at 1920x1080.  There was no way they were thumbnails.
> >
> > JPEG preview may not be the same as JPEG thumbnail in general meaning.
> >
> > E.g. Canon EOS 5D MII stores a small resolution JPEG, full resolution
> > JPEG and raw data in the CR2 files. The full resolution JPEG is kind of
> > equal to the JPEG that camera produces (if raw is not used), but
> > possibly with lower JPEG quality settings.
> >
> > Use
> >
> > $ exiv2 -pp image.cr2
> > Preview 1: image/jpeg, 160x120 pixels, 11197 bytes
> > Preview 2: image/jpeg, 5616x3744 pixels, 1127852 bytes
> >
> > to find out and
> >
> > $ exiv2 -ep1,2 image.cr2
> >
> > to actually extract the first and the second preview JPEG at the same
> > time. (This is not conversion from RAW!)
> >
> > Exiftool may do the same job, read the man page...
> >
> > Regards,
> >
> > Milan Knizek
> > knizek (dot) confy (at) volny (dot) cz
> > http://www.milan-knizek.net - About linux and photography (Czech
> > language only)
> >
> > _______________________________________________
> > Digikam-users mailing list
> > [hidden email]
> > https://mail.kde.org/mailman/listinfo/digikam-users
> >
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users

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[Gilles Caulier-4]

2009/12/23 Adam <[hidden email]>:
> I think canon stores 3 or 4 of them. The TIFF is actually a lossless compressed jpg.

A loosless compressed JPEG. Are you sure ?

JPEG LossLess 12 bits compressor is patented and only used in medical stuff...

Gilles Caulier
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[Adam-268]

If I read this correctly

http://lclevy.free.fr/cr2/



----- Original Message ----

> From: Gilles Caulier <[hidden email]>
> To: digiKam - Home Manage your photographs as a professional with the power of open source <[hidden email]>
> Sent: Wed, December 23, 2009 1:33:57 PM
> Subject: Re: [Digikam-users] How does digiKam do raw conversions for the slide shows ?
>
> 2009/12/23 Adam :
> > I think canon stores 3 or 4 of them. The TIFF is actually a lossless
> compressed jpg.
>
> A loosless compressed JPEG. Are you sure ?
>
> JPEG LossLess 12 bits compressor is patented and only used in medical stuff...
>
> Gilles Caulier
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users

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[Adam-268]

I guess I should have been a little more specific,

the TIFF, when I say tiff I mean the raw data part of the raw, file is compress in a lossless jpg according to

http://lclevy.free.fr/cr2/



----- Original Message ----

> From: Adam <[hidden email]>
> To: digiKam - Home Manage your photographs as a professional with the power of open source <[hidden email]>
> Sent: Wed, December 23, 2009 1:41:27 PM
> Subject: Re: [Digikam-users] How does digiKam do raw conversions for the slide shows ?
>
> If I read this correctly
>
> http://lclevy.free.fr/cr2/
>
>
>
> ----- Original Message ----
> > From: Gilles Caulier
> > To: digiKam - Home Manage your photographs as a professional with the power of
> open source
> > Sent: Wed, December 23, 2009 1:33:57 PM
> > Subject: Re: [Digikam-users] How does digiKam do raw conversions for the slide
> shows ?
> >
> > 2009/12/23 Adam :
> > > I think canon stores 3 or 4 of them. The TIFF is actually a lossless
> > compressed jpg.
> >
> > A loosless compressed JPEG. Are you sure ?
> >
> > JPEG LossLess 12 bits compressor is patented and only used in medical stuff...
> >
> > Gilles Caulier
> > _______________________________________________
> > Digikam-users mailing list
> > [hidden email]
> > https://mail.kde.org/mailman/listinfo/digikam-users
>
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users

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[Linuxguy123]

On Wed, 2009-12-23 at 18:03 +0000, Mark Greenwood wrote:
> > Thanks for the explanation about raws.  I never would have known
> that
> > from shooting over 20,000 of them and converting them to jpegs.
>
> There's no need for sarcasm. I was only trying to help.

Sorry, you are right.  I'm having a stressful day here.  There was no
need for me to do that.  My apologies.

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[Linuxguy123]

On Wed, 2009-12-23 at 18:46 +0100, Gilles Caulier wrote:

> 2009/12/23 Linuxguy123 <[hidden email]>:
> > On Wed, 2009-12-23 at 18:14 +0100, Gilles Caulier wrote:
> >> 2009/12/23 Mark Greenwood <[hidden email]>:
> >> > On Wednesday 23 Dec 2009 16:59:45 Linuxguy123 wrote:
> >> >>
> >> >> How does digiKam generate the images for the raw files it displays in
> >> >> the slide shows ?   How could I easily generate jpegs that look as good
> >> >> as the images in the slideshow ?
> >> >>
> >> >
> >> > I would assume that for the slideshow Digikam is using the embedded
> >> JPEG data from the RAW file and not the RAW data. You can extract the
> >> embedded JPEG using exiftool (though I forget how, try googling it)
> >
> > Thanks for the tip.
> >
> >>  but that really defeats the object of using RAW. When you use RAW you
> >> are expected to do all the white balance etc adjustments yourself. The
> >> embedded JPEG has the camera's built-in adjustments already applied.
> >> If you're going to use the embedded JPEG you may as well just shoot
> >> JPEG in the first place.
> >
> > Thanks for the explanation about raws.  I never would have known that
> > from shooting over 20,000 of them and converting them to jpegs.
> >
> >> Yes, it use JPEG preview. Fast and usefull...
> >
> > Are you serious/ sure this is the case ?  I always thought the preview
> > jpegs were thumbnails.  I displayed the slideshow images on a 52" LCD TV
> > at 1920x1080.  There was no way they were thumbnails.
> >
>
> YES. I'm serious !
>
> RAW are containers. camera record a reduced version (and somethime the
> full version) of JPEG image processed at the same time than RAW file.
> Why ? to reder quicly the image on screen device and TV of course.
>
> This is why preview in digiKam sound always better (in the first
> approach) than the decoded RAW : all the algorithm from camera are
> processed there...
>
> This is not the case of RAW. You need to reproduce the camera job. And
> as each camera maker and model use different algorithm, it's a worse !

Very interesting discussion.  I've learned a lot this morning. Thanks to
everyone who contributed.


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[Mark Greenwood-2]

On Wednesday 23 Dec 2009 18:59:16 Linuxguy123 wrote:
> On Wed, 2009-12-23 at 18:03 +0000, Mark Greenwood wrote:
> > > Thanks for the explanation about raws.  I never would have known
> > that
> > > from shooting over 20,000 of them and converting them to jpegs.
> >
> > There's no need for sarcasm. I was only trying to help.
>
> Sorry, you are right.  I'm having a stressful day here.  There was no
> need for me to do that.  My apologies.

Accepted. I know how it is... :-)

>
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[Photonoxx]

Le Wed, 23 Dec 2009 18:14:29 +0100, Gilles Caulier  
<[hidden email]> a écrit:

>> However, all that said, I've found that the tools in Digikam sometimes  
>> don't cope very well with RAW files - you need accurate icc colour  
>> profiles for your camera, for one thing. Most people seem to like ufraw  
>> for RAW processing, and it does seem to give more "accurate" results  
>> than Digikam does.
>>
>
> I don't use ICC and i always shot in RAW (minolta). Results are fine
> with a some adjustement (saturation). I use auto gamma and 16 bits
> color depth of course.
>
> I never use UFRAW : too complicated for me... and GTK (:=)))
>
> Gilles Caulier

I don't use UFraw which is too complicated for me too. But, I don't find  
full satisfaction "in Digikam way of Raw developping", because I never  
succeed to get an image wich approach enough of the camera proceed  
version, using only with RAWtool parameters and have to apply "post  
treatment" with the raw tool when I open a NEF file in editor. The matter  
for me here is the "post treatment" tab isn't present in all the tools  
which call the RAWtool (in batch RAW conversion tool for example).

So I use CaptureNX2, which reproduce the same development than the camera  
(it's normal because it has the technical data to do this) when I want a  
final use picture. And sometime digikam because it's faster than CaptureNX.

To share my own experience about embed JPG in raw file, i think the NEF  
produced by my D200 contain a thumbnail version and a preview version  
which is (for the dimension) between Thumbnail and RAW data.


--
Nicolas Boulesteix - Chasseur de lueurs - http://www.photonoxx.fr
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[Linuxguy123]

On Wed, 2009-12-23 at 17:08 +0000, Mark Greenwood wrote:
> There's no "easy" way to get good results from RAW, you need to put in
> the effort to 'develop' each shot yourself. With practice you'll soon
> be getting *better* results than the images in the slideshow.

Yeah, I know that.  I'm looking for an automatic way to get those
results.

> However, all that said, I've found that the tools in Digikam sometimes
> don't cope very well with RAW files

Workflow wise, they are GREAT.  Results wise, very poor.

> - you need accurate icc colour profiles for your camera, for one
> thing.

There seems to be some debate about that.

Furthermore, one can get the icc curve- if its in there- from the raw
file using exiftool.

http://www.sno.phy.queensu.ca/~phil/exiftool/ 

> Most people seem to like ufraw for RAW processing, and it does seem to
> give more "accurate" results than Digikam does.

I hate to say it, but I agree.  Not that there is anything wrong with
ufraw, it just isn't supported in digiKam.

So what should we do about this problem ?  Fix the converter that
digiKam uses or write a plugin that allows the use of ufraw ?

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[Linuxguy123]

On Wed, 2009-12-23 at 19:03 +0100, Milan Knížek wrote:

> JPEG preview may not be the same as JPEG thumbnail in general meaning.
>
> E.g. Canon EOS 5D MII stores a small resolution JPEG, full resolution
> JPEG and raw data in the CR2 files. The full resolution JPEG is kind of
> equal to the JPEG that camera produces (if raw is not used), but
> possibly with lower JPEG quality settings.
>
> Use
>
> $ exiv2 -pp image.cr2
> Preview 1: image/jpeg, 160x120 pixels, 11197 bytes
> Preview 2: image/jpeg, 5616x3744 pixels, 1127852 bytes
>
> to find out and
>
> $ exiv2 -ep1,2 image.cr2
>
> to actually extract the first and the second preview JPEG at the same
> time. (This is not conversion from RAW!)

>From one of my images:

$ exiv2 IMG_1551.CR2
File name       : IMG_1551.CR2
File size       : 16094373 Bytes
MIME type       : image/x-canon-cr2
Image size      : 4272 x 2848
Camera make     : Canon
Camera model    : Canon EOS DIGITAL REBEL XSi
Image timestamp : 2009:12:19 02:40:35
Image number    :
Exposure time   : 1/60 s
Aperture        : F5.6
Exposure bias   : 0 EV
Flash           : Yes, compulsory
Flash bias      : 0 EV
Focal length    : 29.0 mm
Subject distance: 0
ISO speed       : 800
Exposure mode   : Manual
Metering mode   : Multi-segment
Macro mode      : Off
Image quality   : RAW
Exif Resolution : 2256 x 1504
White balance   : Auto
Thumbnail       : image/jpeg, 7397 Bytes
Copyright       :
Exif comment    :

$ exiv2 -pp IMG_1551.CR2
Preview 1: image/jpeg, 160x120 pixels, 7397
bytes                          
Preview 2: image/jpeg, 2256x1504 pixels, 651767 bytes  

So the raw image (4272 x 2848) would have even more resolution than the
large EXIF image (2256 x 1504) that was used on the slide show.




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