Preview is "better" than RAW conversion?

[Niels Ott]

Hi there,

I take my pictures with a Pentax K-7 in PEF format. When I view the PEFs
in DigiKam, they usually look quite nice already.

However, when I use the RAW converter to convert a batch of images, I
just don't manage to make them look as good as in the preview.
Especially the contrast is often too low. I don't know what's going on here.

It doesn't matter really to me for good shots which I manually "develop"
in the image editor, but for giving someone a bunch of pictures, it's a
shame that those images always look flawed compared to cheap jpeg
shooters. 8-)

If DigiKam does quite well automatically in Preview, why can't it also
ofter the same automatic quality in the RAW converter?


Best

   Niels




--
Niels Ott
Bassist und so bei Delta B
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[Remco Viëtor]

On Sunday 31 August 2014 12:09:48 Niels Ott wrote:
> Hi there,
>
> I take my pictures with a Pentax K-7 in PEF format. When I view the PEFs
> in DigiKam, they usually look quite nice already.
>
> However, when I use the RAW converter to convert a batch of images, I
> just don't manage to make them look as good as in the preview.
> Especially the contrast is often too low. I don't know what's going on
here.

>
> It doesn't matter really to me for good shots which I manually "develop"
> in the image editor, but for giving someone a bunch of pictures, it's a
> shame that those images always look flawed compared to cheap jpeg
> shooters. 8-)
>
> If DigiKam does quite well automatically in Preview, why can't it also
> ofter the same automatic quality in the RAW converter?
>
>
> Best
>
>    Niels

What you see in the preview is the jpeg embedded in the Raw file (which is
a quarter size).

That preview jpeg has had all the treatments applied to it that a 'normal'
in camera jpeg would get, including brightness, contrast, and saturation
adjustments, and noise reduction and sharpening.

If you do your own RAW development, those adjustments are not automatically
applied (although some RAW developers from the camera makers do apply
them).
Particularly sharpening will have to be applied separately, and you always
need some sharpening (to correct for the anti-alias filter in the camera,
and the softness from the demosaicing)

Regards,

Remco
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Le 31/08/2014 12:09, Niels Ott a écrit :

> If DigiKam does quite well automatically in Preview, why can't it also
> ofter the same automatic quality in the RAW converter?


il semble y avoir des spucis avec l'export jpg, encore que ma version
(courante sur openSUSE) soit trop ancienne pour en juger vraiment

jdd


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[Gilles Caulier-4]

Preview is JPEG embedded in RAW processed by camera firmware. It's the
same image than your RAW but taken in JPEG and with a reduced size.

RAW is unprocessed image by your camera firmware. This is why we spell
"RAW" image...

Gilles Caulier

2014-08-31 12:09 GMT+02:00 Niels Ott <[hidden email]>:

> Hi there,
>
> I take my pictures with a Pentax K-7 in PEF format. When I view the PEFs
> in DigiKam, they usually look quite nice already.
>
> However, when I use the RAW converter to convert a batch of images, I
> just don't manage to make them look as good as in the preview.
> Especially the contrast is often too low. I don't know what's going on here.
>
> It doesn't matter really to me for good shots which I manually "develop"
> in the image editor, but for giving someone a bunch of pictures, it's a
> shame that those images always look flawed compared to cheap jpeg
> shooters. 8-)
>
> If DigiKam does quite well automatically in Preview, why can't it also
> ofter the same automatic quality in the RAW converter?
>
>
> Best
>
>    Niels
>
>
>
>
> --
> Niels Ott
> Bassist und so bei Delta B
> http://www.delta-b.net
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users

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[Remco Viëtor]

On Sunday 31 August 2014 12:38:28 jdd wrote:

> Le 31/08/2014 12:09, Niels Ott a écrit :
>
> > If DigiKam does quite well automatically in Preview, why can't it also
> > ofter the same automatic quality in the RAW converter?
>
>
> il semble y avoir des spucis avec l'export jpg, encore que ma version
> (courante sur openSUSE) soit trop ancienne pour en juger vraiment
>
> jdd

Pas très clair, les soucies pourraient être dans le marquage.

Et on n'est pas encore à l'exportation ici, just au developpement RAW.
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[Niels Ott]

Am 31.08.2014 um 12:38 schrieb jdd:
> Le 31/08/2014 12:09, Niels Ott a écrit :
>
>> If DigiKam does quite well automatically in Preview, why can't it also
>> ofter the same automatic quality in the RAW converter?
>
>
> il semble y avoir des spucis avec l'export jpg, encore que ma version
> (courante sur openSUSE) soit trop ancienne pour en juger vraiment

I don't think it's an issue with the JPEG writer of the batch raw
converter, PNGs look just the same.

   Niels


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Le 31/08/2014 12:38, jdd a écrit :

> Le 31/08/2014 12:09, Niels Ott a écrit :
>
>> If DigiKam does quite well automatically in Preview, why can't it also
>> ofter the same automatic quality in the RAW converter?
>
>
> il semble y avoir des spucis avec l'export jpg, encore que ma version
> (courante sur openSUSE) soit trop ancienne pour en juger vraiment
>
> jdd
>
>

sorry I missed the language :-(

jdd

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[Niels Ott]

Am 31.08.2014 um 12:36 schrieb Remco Viëtor:

> That preview jpeg has had all the treatments applied to it that a 'normal'
> in camera jpeg would get, including brightness, contrast, and saturation
> adjustments, and noise reduction and sharpening.
>
> If you do your own RAW development, those adjustments are not automatically
> applied (although some RAW developers from the camera makers do apply
> them).
> Particularly sharpening will have to be applied separately, and you always
> need some sharpening (to correct for the anti-alias filter in the camera,
> and the softness from the demosaicing)

Thanks for the explanation, Remco & Gilles!

I knew that there was an embedded JPEG preview but I didn't think
DigiKam would use it since I thought it was too small.

I know that those adjustments have to be applied in RAW development
manually, this is what I do for good shots and I usually like the
results better than the preview.

Concerning sharpening, I only do this when it comes to actual usage of
the image - this is why I store edited images as PNG. For web use, I
usually open them in Gimp, resize them and then apply the unsharp mask
filter. For prints, I use the sharpening of DigiKam and save as PNG
again. (Even though, most likely the prints don't make show 16bit color
depth, so I could also do this in Gimp and save as 100% quality JPEGs)

It's just that sometimes I want to give people all pictures from an
event quickly and they should look great. (The pictures, not the people.
Well, both.)

So what I've learned is that DigiKam can't replicate the behavior of my
camera that creates the JPEG preview in the PEFs. Or is there a way?

Otherwise I guess I'd go for shooting in PEF+JPEG, which the K-7 can do.
(My K100D that I've been using for years was not able to do this. BTW,
I'm about to sell it. Anyone? ;-) )

   Niels




>
> Regards,
>
> Remco
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>


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[Daniel Bauer-2]

Am 31.08.2014 12:54, schrieb Niels Ott:
> Am 31.08.2014 um 12:36 schrieb Remco Viëtor:

> So what I've learned is that DigiKam can't replicate the behavior of my
> camera that creates the JPEG preview in the PEFs. Or is there a way?

I found that the original raw converters from camera manufacturers in
general are easier in handling raws than anything I found on linux.
(Except the crap of software that Sony delivers, which is really
useless, and a disgrace for such lovely cameras...)

For Win and Mac there is DxO Optics Pro which can apply all the camera
suggestions of many manufacturers (e.g. make an image just like the
cameras jpg, which sometimes is a good base to start). Unfortunately
it's price is obscene, but maybe you can find a free version somewhere...

> Otherwise I guess I'd go for shooting in PEF+JPEG, which the K-7 can do.

I do that all the time. Jpgs don't use up much space and for many
purposes they are just good enough.


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professional photography: http://www.daniel-bauer.com
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[Jeff Robinson]

On 31/08/2014 6:28 AM, Daniel Bauer wrote:

> Am 31.08.2014 12:54, schrieb Niels Ott:
>> Am 31.08.2014 um 12:36 schrieb Remco Viëtor:
>
>> So what I've learned is that DigiKam can't replicate the behavior of my
>> camera that creates the JPEG preview in the PEFs. Or is there a way?
>
> I found that the original raw converters from camera manufacturers in
> general are easier in handling raws than anything I found on linux.
> (Except the crap of software that Sony delivers, which is really
> useless, and a disgrace for such lovely cameras...)
>
> For Win and Mac there is DxO Optics Pro which can apply all the camera
> suggestions of many manufacturers (e.g. make an image just like the
> cameras jpg, which sometimes is a good base to start). Unfortunately
> it's price is obscene, but maybe you can find a free version somewhere...
>
>> Otherwise I guess I'd go for shooting in PEF+JPEG, which the K-7 can do.
>
>
> I do that all the time. Jpgs don't use up much space and for many
> purposes they are just good enough.
>
>

Hi folks,

If it is of any interest, I bashed together a small script that will
copy the preview JPEG (which I believe is full size and already
processed) out of Pentax RAW (PEF) files.

The script works (using ufraw-batch) against either a whole directory or
will convert files based on names supplied, either single or multiple files.

Once the JPEG has been extracted the script then copies the XMP file
from the PEF to the JPEG and uses exiftool to write the EXIF information
from the PEF to the new JPEG as well.

In my current work-flow I keep everything RAW and only convert a few of
the files to JPEG and process those by hand, but the ones I can't quite
ever get where I want, these scripts come in incredibly handy.

I can post them if folks want... I'm not certain if that's against the
list policy.  The script is about 50 lines long.

Now... if someone could figure out how to hook this script directly into
Digikam I'd be ecstatic!

Jeff
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[Niels Ott]

Jeff,

I'd be very happy to have this script. And a digiKam integration would
be so great.

After all, this would fit my purposes very well. I could give people a
pile of JPEGs and let them know: This is the automatic thing in reduced
resolution, if you want some of those in real good quality, just let me
know.

So why not posting your script here, I don't see any problem with that.

I think this should make it into the extras menu, something like
"Extract JPEG preview from RAW"

Best

   Niels


Am 31.08.2014 um 14:08 schrieb Jeff Robinson:

> Hi folks,
>
> If it is of any interest, I bashed together a small script that will
> copy the preview JPEG (which I believe is full size and already
> processed) out of Pentax RAW (PEF) files.
>
> The script works (using ufraw-batch) against either a whole directory or
> will convert files based on names supplied, either single or multiple
> files.
>
> Once the JPEG has been extracted the script then copies the XMP file
> from the PEF to the JPEG and uses exiftool to write the EXIF information
> from the PEF to the new JPEG as well.
>
> In my current work-flow I keep everything RAW and only convert a few of
> the files to JPEG and process those by hand, but the ones I can't quite
> ever get where I want, these scripts come in incredibly handy.
>
> I can post them if folks want... I'm not certain if that's against the
> list policy.  The script is about 50 lines long.
>
> Now... if someone could figure out how to hook this script directly into
> Digikam I'd be ecstatic!
>
> Jeff
> _______________________________________________
> Digikam-users mailing list
> [hidden email]
> https://mail.kde.org/mailman/listinfo/digikam-users
>

--
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http://www.delta-b.net
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[Remco Viëtor]

> Am 31.08.2014 um 14:08 schrieb Jeff Robinson:
> > Hi folks,
> >
> > If it is of any interest, I bashed together a small script that will
> > copy the preview JPEG (which I believe is full size and already
> > processed) out of Pentax RAW (PEF) files.
> >
> > The script works (using ufraw-batch) against either a whole directory
or
> > will convert files based on names supplied, either single or multiple
> > files.
> >
> > Once the JPEG has been extracted the script then copies the XMP file
> > from the PEF to the JPEG and uses exiftool to write the EXIF
information

> > from the PEF to the new JPEG as well.
> >
> > In my current work-flow I keep everything RAW and only convert a few of
> > the files to JPEG and process those by hand, but the ones I can't quite
> > ever get where I want, these scripts come in incredibly handy.
> >
> > I can post them if folks want... I'm not certain if that's against the
> > list policy.  The script is about 50 lines long.
> >
> > Now... if someone could figure out how to hook this script directly

into
> > Digikam I'd be ecstatic!

Another option if you use Linux would be to use dcraw:

# dcraw -e <filename>

To use that on a series of raw files in a directory, do something like

# for f in *.PEF ; do dcraw -e $f ; done

Regards,

Remco

P.S. note that you might not want to provide full metadata with the jpegs,
especially geolocation data. Copyright info isn't in there, and the rest
isn't particularly useful for non-photographers
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[Jeff Robinson]

Hi Niels,

Here is the script that I cobbled together.  Let it be known that
there's absolutely no error checking or good coding practices contained
with-in!

I also mispoke when I said that this script used the preview... it looks
like PEF contains an embedded JPEG that is (almost) the same resolution
as the RAW file.  In a test the GIMP brings my RAW file in at 3040px x
2024px and the embedded JPEG at 3008px x 2000px.  Of course, my camera
is also a K100, and perhaps with a higher megapixel count the embedded
image is reduced.  Either way, here is the script and you'll be able to
compare the output.

Hopefully the word-wrap doesn't mangle the script too much.

#!/usr/bin/perl
# This script is used for extract JPEG previews from PEF files and then
copies over EXIF information
# When run with-out arguments the script will copy the JPEG previews and
EXIF information from
# all the PEF files in the current directory
# Otherwise a single or multiple file names can be list after the command
#
# JPEGs wil have the format of $filename.embedded.jpeg which matches the
output of ufraw-batch
#
# usage:
# arg_batch_and_tag
# or
# arg_batch_and_tag filename [filename2] [filename3]...
#
# Require software:
# ufraw-batch, which is part of ufraw: http://ufraw.sourceforge.net/
# exiftool, which is part of ExifTool:
http://www.sno.phy.queensu.ca/~phil/exiftool/
#
# (C)2014 Jeff Robinson
# This program is free software; you can redistribute it and/or modify
it under
# the terms of the GNU General Public License version 2, as published by the
# Free Software Foundation.

use Cwd;

my $totalarg = $#ARGV + 1;
my $curdir = cwd();

if ( $totalarg = 0 ) {
# No arguments were given so we'll run the script against all files in
the current directory

print "My current working directory is $curdir \n";

system("ufraw-batch --embedded-image *.pef");
system("ufraw-batch --embedded-image *.PEF");

opendir(DIR, $curdir);
@files = grep (/\.pef$/i,readdir(DIR));
closedir(DIR);

foreach $file (@files) {
        print "Copying EXIF information from $file...";
        $file =~ s/\.[^.]*$//;
        system("exiftool -overwrite_original_in_place -tagsFromFile $file.pef
$file.embedded.jpg");
        system("exiftool -overwrite_original_in_place -tagsFromFile $file.PEF
$file.embedded.jpg");
        print "completed.\n";
}

} else {
  # Use the supplied arguments as the files to process

  @files = grep (/\.pef$/i,@ARGV);

  foreach $file (@files) {
    $file =~ s/(.+)\.[^.]+$/$file/;
    $fileNoExtension = remove_extension($file);

    print("Extracting embedded image...\n");
    system("ufraw-batch --embedded-image \"$curdir/$file\"");
    print("Copying xmp file...\n");
    system("cp \"$curdir/$file.xmp\"
\"$curdir/$fileNoExtension.embedded.jpg.xmp\"");
    print("Writing EXIF information from original file to JPEG.\n");
    system("exiftool -overwrite_original_in_place -tagsFromFile
\"$file\" \"$fileNoExtension.embedded.jpg\"");
    print("Finished.\n\n");
  }

}

sub remove_extension {
    my $filename = shift @_;

    $filename =~ s/
                (.)             # matches any character
                \.              # the literal dot starting an extension
                [^.]+           # one or more NON-dots
                $               # end of the string
        /$1/x;

    return $filename;
}





On 08/31/2014 07:17 AM, Niels Ott wrote:

> Jeff,
>
> I'd be very happy to have this script. And a digiKam integration would
> be so great.
>
> After all, this would fit my purposes very well. I could give people a
> pile of JPEGs and let them know: This is the automatic thing in reduced
> resolution, if you want some of those in real good quality, just let me
> know.
>
> So why not posting your script here, I don't see any problem with that.
>
> I think this should make it into the extras menu, something like
> "Extract JPEG preview from RAW"
>
> Best
>
>    Niels
>
>
> Am 31.08.2014 um 14:08 schrieb Jeff Robinson:
>> Hi folks,
>>
>> If it is of any interest, I bashed together a small script that will
>> copy the preview JPEG (which I believe is full size and already
>> processed) out of Pentax RAW (PEF) files.
>>
>> The script works (using ufraw-batch) against either a whole directory or
>> will convert files based on names supplied, either single or multiple
>> files.
>>
>> Once the JPEG has been extracted the script then copies the XMP file
>> from the PEF to the JPEG and uses exiftool to write the EXIF information
>> from the PEF to the new JPEG as well.
>>
>> In my current work-flow I keep everything RAW and only convert a few of
>> the files to JPEG and process those by hand, but the ones I can't quite
>> ever get where I want, these scripts come in incredibly handy.
>>
>> I can post them if folks want... I'm not certain if that's against the
>> list policy.  The script is about 50 lines long.
>>
>> Now... if someone could figure out how to hook this script directly into
>> Digikam I'd be ecstatic!
>>
>> Jeff
>> _______________________________________________
>> Digikam-users mailing list
>> [hidden email]
>> https://mail.kde.org/mailman/listinfo/digikam-users
>>
>
>

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[Boudewijn]

Hi Niels,

On Sunday 31 August 2014 12:09:48 Niels Ott wrote:
> I take my pictures with a Pentax K-7 in PEF format. When I view the PEFs
> in DigiKam, they usually look quite nice already.
Shot in the dark: do you maybe see the embedded jpeg when quickviewing the
PEF? As far as I know, most raw formats embed a jpeg for quick viewing on the
camera display.

> However, when I use the RAW converter to convert a batch of images, I
> just don't manage to make them look as good as in the preview.
> Especially the contrast is often too low. I don't know what's going on
> here.
If the PEF format supports a wide dynamic range (and your sensor captures it),
then the pictures will look bland on a viewing device that has a narrower
dynamic range. Pictures with lower dynamic ranges show pitch black and pure
white, where a higher dynamic range still provides shades of (dark)
grey/colour and (light) grey and colour.

Could the above explain what you see?

Best regards,

Boudewijn
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[Niels Ott-2]

Am 31.08.2014 um 14:36 schrieb Remco Viëtor:
> Another option if you use Linux would be to use dcraw:
>
> # dcraw -e <filename>

I found a trivial way to do this from DigiKam in a
batch-processing-style manner in KDE:

1. Select your RAW files in DigiKam
2. Right-Click and select "Open with"
   -> Pick "others"
3. Enter dcraw -e into command box.
   -> klick OK

You could edit the file types in Konqueror/Dolphin and add something
like "Extract JPEG from RAW" to RAW or PEF, so you wouldn't have to type
the command name each time.

Best

   Niels


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