Recent comments

Reply to: What exactly is pre_mul in libraw_colordata_t?   20 hours 55 min ago

I see. Thanks for the prompt reply!

Reply to: What exactly is pre_mul in libraw_colordata_t?   1 day 4 hours ago

_rgb_cam (input data) is similar to DNG CameraMatrixN (https://www.adobe.com/content/dam/acom/en/products/photoshop/pdfs/dng_sp...) so contains both color transform and D65 WB coefficients.

Reply to: Issue while converting CR3 using draw_emu   3 weeks 5 days ago

What version of LibRaw do you use?

Reply to: Building, shipping libraw on macos Big Sur   1 month 3 weeks ago

Hi Alex,

thank you very much. I appreciated your quick reply.

Confirmed, it does the trick.

Thilo

Reply to: Building, shipping libraw on macos Big Sur   1 month 3 weeks ago

make -f Makefile.dist
should do the trick

Reply to: DNG recorder   2 months 1 day ago

LibRaw is not about RAW writing, but about reading.

Reply to: Canon AFInfoData mismatch with ExifTool parsed result   2 months 5 days ago

ok, I get it.

Reply to: Canon AFInfoData mismatch with ExifTool parsed result   2 months 5 days ago

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

Reply to: Read exif issue from panasonic raw file   2 months 5 days ago

Thanks for your reply and advice.

I've solved the panasonic rw2 issue.

Reply to: Read exif issue from panasonic raw file   2 months 1 week ago

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)

Reply to: Read exif issue from panasonic raw file   2 months 1 week ago

Hi, sorry to bother you again.

  | 9)  ExifOffset (SubDirectory) -->
  |     - Tag 0x8769 (4 bytes, int32u[1]):
  |         008a: ae 02 00 00                                     [....]
  | + [ExifIFD directory with 42 entries]
  | | 0)  ExposureTime = 0.002 (10/5000)
  | |     - Tag 0x829a (8 bytes, rational64u[1]):
  | |         04c4: 0a 00 00 00 88 13 00 00                         [........]

Don't know how the offset works,

0x008a + 4 + 0x02ae does not equal to 0x04c4
Reply to: Read exif issue from panasonic raw file   2 months 1 week ago

Thanks for the tip. I'm trying to parse and get the data from lr_ptr->imgdata.thumbnail.thumb

Reply to: Read exif issue from panasonic raw file   2 months 1 week ago

I 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

Reply to: Read exif issue from panasonic raw file   2 months 1 week ago

Great, I didn't know that the 0x004d tag is not in Raw exif but in thumbnail exif. Thanks for the advice.

Reply to: Read exif issue from panasonic raw file   2 months 1 week ago

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

Reply to: Read exif issue from panasonic raw file   2 months 1 week ago

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/

Reply to: Panny Lumix GH5 II RAW   2 months 1 week ago

in the next public snapshot (this Fall)

Reply to: Read exif issue from panasonic raw file   2 months 1 week ago

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)

Reply to: Windows & LCMS   2 months 1 week ago

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?

Reply to: Phase One IIQ decoding   2 months 4 weeks ago

According to your code, you use 'all defaults' for libraw processing (dcraw_process), so daylight white balance and automatic 1%-ETTR brightness correction.

Reply to: I think the ACES color profile in libraw is incorrect   3 months 3 weeks ago

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)

Reply to: I think the ACES color profile in libraw is incorrect   3 months 3 weeks ago

I realize that, just thinking out loud pragmatically 😉

I guess there are ProPhoto and Rec2020 outputs available to cover a "similar" range and precision...

Reply to: I think the ACES color profile in libraw is incorrect   3 months 3 weeks ago

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 ;)

Reply to: I think the ACES color profile in libraw is incorrect   3 months 3 weeks ago

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?

Reply to: I think the ACES color profile in libraw is incorrect   3 months 3 weeks ago

> 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...

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