questions about the raw importer
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questions about the raw importer
 
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Hi all,
today I spent some time with digikam's new raw importer in 0.9.5svn and can confirm once again that it has improved a lot over the previous versions. Nontheless, I would like to ask some unrelated questions about it. 1) white balance. Do the settings "default D65", "camera", "automatic" just correspond to fixing some value of the temperature? Or are there some more internal settings involved? If it's only the temperature (and green tint, maybe), it would be helpful if the chosen temperature would be indicated on the slider, with dragging the slider changing whitebalance to manual mode. Moreover, there is a funny error in the German translation. While "Handbuch" is the correct translation of "manual" in the sense of the manual which the user is supposed to read, the "manual" mode meant here is "manuell" or "benutzerdefiniert" in German, not "Handbuch". 2) black and white. I don't understand these settings very well, but that's probably due to my limited photography knowledge ;-) My guess is that with these sliders, you can cut off the spectrum at the left or right hand side. Is that correct? If yes, it would be great if this cut off could be visualized in the spectrum depicted in the importer. Or how can I see what value is appropriate? 3) luminosity curve. For consistency with the rest of digikam, maybe for "reset to linear" the same button as for all the other reset buttons could be used. The micro button which is used right now can actually easily be overlooked. 4) workflow for imported images. After the raw image is imported, usually some more adjustments like crop, sharpen, etc are made. What is the intended workflow here? I started out with importing the raw image, save it to something non-raw, and then do further adjustments. Or can the tools in the image editor work directly on the raw data? Well, when I save the imported X.raw to, say, X.jpg and then do some more changes, I have the problem that saving after these changes does not work - digikam refuses to overwrite X.jpg with the changed X.jpg, and I am forced to pick a new file name. So I usually import, save to jpg, close the image editor, open the jpg again and then do the other adjustments. Best regards, Gandalf _______________________________________________ Digikam-users mailing list [hidden email] https://mail.kde.org/mailman/listinfo/digikam-users |
Re: questions about the raw importer
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2008/9/2 Gandalf Lechner <[hidden email]> Hi all, Use SHIFT F1 over the settings to have explainations. Or are there some more internal settings i like the idea. 2) black and white. yes. it's the black point and white point. If yes, this is that i would to do but with dcraw it's impossible. The histogram to cut is an internal one used during the demosaiced process. i will trying to see if libraw will be better for that
planed.
no. editor use a demosaiced image converted to RGB color space. Well, when I save the imported X.raw to, say, X.jpg I don't recommend to use JPG in your workflow. Use PNG instead. your problem to overwrite an existing image is new for me. Somebody can reproduce it ? best Gilles Caulier _______________________________________________ Digikam-users mailing list [hidden email] https://mail.kde.org/mailman/listinfo/digikam-users |
Re: questions about the raw importer
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Hi Gilles and thanks for the fast answers.
Regarding png vs jpg: > I don't recommend to use JPG in your workflow. Use PNG instead. Yes I would like to use a lossless file format, but with png I have the problem that it can produce really big files. For example, I have a raw (cr2) file 9.7 MB big, but the png version I got from the digikam converter is 42MB! In comparison to 1.1 MB for the jpg that's just way too big; in particular since it's much larger than the raw itself. Best, Gandalf > your problem to overwrite an existing image is new for me. Somebody can > reproduce it ? > > best > > Gilles Caulier _______________________________________________ Digikam-users mailing list [hidden email] https://mail.kde.org/mailman/listinfo/digikam-users |
Re: questions about the raw importer
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2008/9/3 Gandalf Lechner <[hidden email]> Hi Gilles and thanks for the fast answers. PNG (or TIFF) file size against RAW file size are relevant of 2 points: - 1/ image data are in RGB color space and take more place. - 2/ image data are lossless compressed (deflate compression for PNG and TIFF) Both file format don't know wavelet compression yet. Alternative to PNG or TIFF : - JPEG2000 : wavelet/lossless compression and support all metadata (need future Exiv2 0.18 for that). File size are reduced (x1/2 - 1/4 against PNG). Big problem : it very slow to compress/uncompress - DNG : use lossless JPEG compression with 16 bits color depth (not wavelet based). file size reduced (x1/2) but DNG SDK is patented, do not support Linux as well, and documentation is dumy for developpers. Licence is not opensource but you can use as well with many restriction. - HDPhoto : wavelet based. file size reduced (as JPEG 2000). But it's M$ stuff patented and do not support Linux as well, and licence is anti open source. I recommend to read my blog entry for details : http://www.digikam.org/drupal/node/368 Best Gilles
_______________________________________________ Digikam-users mailing list [hidden email] https://mail.kde.org/mailman/listinfo/digikam-users |
Re: questions about the raw importer
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2008/9/3 Gilles Caulier <[hidden email]>
I forget to said that a possible opensource alternative will be OpenEXR which use a loosless compression based on wavelet. The problem is metadata support. I currently investiguate this point to support this foramt in digiKam as new photo container. Gilles _______________________________________________ Digikam-users mailing list [hidden email] https://mail.kde.org/mailman/listinfo/digikam-users |
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