LibRaw is NOT a complete EXIF/Makernotes parser. We're focused on data that needed for RAW processing, other fields are optional. Please use some other software for complete metadata parsing and interpretation
1)Not sure what is displayed by exiftool, it may be offset from file beginning, not from jpeg preview start.
(hard to tell without having the file)
2) tags larger than 4 bytes contains offset (relative to IFD start), not exact value, so one need to seek to this offset to read the data. There is not enough output in your quote to check this.
BTW, I suggest you to not invent the wheel :), but use some exif parser (e.g. exiv2 if you can tolerate GPL licensing)
Could you please point out how you made it work with VS?
I have also compiled Libraw with enabled LCMS (by modifying Makefile.msvc file) and the generated executables work just fine supporting LCMS. However, not when I link Libraw to my VS. It still seems like it doesn't support LCMS. any advice?
According to your code, you use 'all defaults' for libraw processing (dcraw_process), so daylight white balance and automatic 1%-ETTR brightness correction.
There's other huge gamuts too, like xTremeRGB , MaxRGB, and AllColorsRGB. None of these are in libraw, but the description of xtremeRGB says that, "CAUTION: XtremeRGB may cause hallucinations or eye cancer." (http://www.hutchcolor.com/profiles.html)
LibRaw is limited to whatever raw data is. Processing of raw data (white balance, colour space conversion, gamma) is out of the scope of main LibRaw functionality, we keep such processing for testing purposes only. LibRaw is not a raw converter and isn't meant to be one ;)
> My apologies if I offended or annoyed you.
Not in the least.
> I was under the mistaken impression that the ICC profiles are simply assigned on output
They are not, but even if they were, what good is it to assign one profile while converting to a different one?
I checked, and yes, Coffin's aces_rgb matrix isn't adapted to D65.
I think I made it clear what I'm referring to, and so did you. We can't fix what is not there. Your proposal is technically impossible (and in any case, the starting point is the matrix in the standard), and I explained what we are going to do. Let's return to the topic only when there will be anything new to discuss.
Hi Alex,
thank you very much. I appreciated your quick reply.
Confirmed, it does the trick.
Thilo
make -f Makefile.dist
should do the trick
LibRaw is not about RAW writing, but about reading.
ok, I get it.
LibRaw is NOT a complete EXIF/Makernotes parser. We're focused on data that needed for RAW processing, other fields are optional. Please use some other software for complete metadata parsing and interpretation
Thanks for your reply and advice.
I've solved the panasonic rw2 issue.
1)Not sure what is displayed by exiftool, it may be offset from file beginning, not from jpeg preview start.
(hard to tell without having the file)
2) tags larger than 4 bytes contains offset (relative to IFD start), not exact value, so one need to seek to this offset to read the data. There is not enough output in your quote to check this.
BTW, I suggest you to not invent the wheel :), but use some exif parser (e.g. exiv2 if you can tolerate GPL licensing)
Hi, sorry to bother you again.
Don't know how the offset works,
Thanks for the tip. I'm trying to parse and get the data from
lr_ptr->imgdata.thumbnail.thumbI used the exiftool program to see the structure (with -v3 command line key to see details)
It clearly shows this:
| 32) JpgFromRaw (SubDirectory) -->
| - Tag 0x002e (713278 bytes, undef[713278]):
[skip[
--- DOC1:JpgFromRaw --------------------------------------------------------
JPEG APP1 (50684 bytes):
0006: 45 78 69 66 00 00 49 49 2a 00 08 00 00 00 10 00 [Exif..II*.......]
[skip]
ExifByteOrder = II
+ [IFD0 directory with 16 entries]
and 0x004d is within Makernotes pointed by this (JpgFromRaw) EXIF
Great, I didn't know that the 0x004d tag is not in Raw exif but in thumbnail exif. Thanks for the advice.
I do not know what specific camera you're talking about.
Just inspected some GH5S file. For this file 0x004d/AFPointPosition tag is not in IFD0, but in makernotes section of EXIF.
The bad thing: this is NOT RAW/EXIF, but EXIF contained in embedded JPEG preview.
So, to extract the data you need:
- extract thumbnail (preview) using LibRaw::unpack_thumb
- use some EXIF parser to parse thumbnail's EXIF
I've tried to use these code to catch the exif tag data.
void exif_cb(void *context, int tag, int type, int len, unsigned int ord, void *ifp, INT64 base) { print(tag); if (tag == (0x004d | 0x30000)) { print("get the 0x004d tag"); } }0x004d is from https://exiftool.org/TagNames/Panasonic.html named "AFPointPosition".
I can get all the tags printed, but no "0x004d" found.
p.s.
The rw2 raw file i'm using can be extracted a "0x004d" AFPointPosition tag data by the ExifTool downloaded from https://exiftool.org/
in the next public snapshot (this Fall)
You may try to use 'exif callback': https://www.libraw.org/docs/API-CXX.html#exif
Note: for panasonic's main IFD, tag is or-ed with 0x30000 (to distinguish from normal tiff ifd)
Could you please point out how you made it work with VS?
I have also compiled Libraw with enabled LCMS (by modifying Makefile.msvc file) and the generated executables work just fine supporting LCMS. However, not when I link Libraw to my VS. It still seems like it doesn't support LCMS. any advice?
According to your code, you use 'all defaults' for libraw processing (dcraw_process), so daylight white balance and automatic 1%-ETTR brightness correction.
There's other huge gamuts too, like xTremeRGB , MaxRGB, and AllColorsRGB. None of these are in libraw, but the description of xtremeRGB says that, "CAUTION: XtremeRGB may cause hallucinations or eye cancer." (http://www.hutchcolor.com/profiles.html)
I realize that, just thinking out loud pragmatically 😉
I guess there are ProPhoto and Rec2020 outputs available to cover a "similar" range and precision...
LibRaw is limited to whatever raw data is. Processing of raw data (white balance, colour space conversion, gamma) is out of the scope of main LibRaw functionality, we keep such processing for testing purposes only. LibRaw is not a raw converter and isn't meant to be one ;)
Btw, I'm wondering how useful (or harmful?) is it to have that huge ACES AP0 output color space when LibRaw is limited to uint16 representation...
Sounds like an AP1-based ACEScg D65 adapted option would be good to have as well?
One should perhaps clarify in the docs that AP0 based "ACES2065-1 adapted to D65" is meant by the existing "ACES" enum?
> My apologies if I offended or annoyed you.
Not in the least.
> I was under the mistaken impression that the ICC profiles are simply assigned on output
They are not, but even if they were, what good is it to assign one profile while converting to a different one?
I checked, and yes, Coffin's aces_rgb matrix isn't adapted to D65.
Fixed in master now (the changes are in src/tables/colorconst.cpp) https://github.com/LibRaw/LibRaw/commit/1974214acf47ef260853d74006765746...
My apologies if I offended or annoyed you. I was under the mistaken impression that the ICC profiles are simply assigned on output
I think I made it clear what I'm referring to, and so did you. We can't fix what is not there. Your proposal is technically impossible (and in any case, the starting point is the matrix in the standard), and I explained what we are going to do. Let's return to the topic only when there will be anything new to discuss.
To which matrices are you referring? The cam2rgb matrices? I am talking about what's in the actual icc profiles embedded in the images, to be clear.
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