Recent comments

Reply to: Generating ColorMatrix1 from input data   7 months 1 week ago

I'm having the same problem, Have you found any solution that you can share?

Reply to: Working with Apple iPhone ?   7 months 2 weeks ago

LibRaw supports iPhone's DNG files, but not HEIC files.

Reply to: iPhone 11 Halide DNG gives black image.   7 months 2 weeks ago

Here is TIFF-file created by dcraw_emu -w -T [your-file]: https://www.dropbox.com/s/b4st4g9o5846l6f/IMG_2407.DNG.tiff?dl=0
(tested with public snapshot/github version).

I do not see any problems here

Reply to: Fuji X-Trans files opening slow   7 months 2 weeks ago

dcraw_make_mem_image is the last step, applied after all postprocessing steps.

I suggest you to play with quality settings and/or half-size output. Also, OpenMP may help with default quality settings.

Reply to: Fuji X-Trans files opening slow   7 months 2 weeks ago

I am using "libraw_dcraw_make_mem_image". Maybe this is the issue. What should I use instat ?

Reply to: Fuji X-Trans files opening slow   7 months 2 weeks ago

What demosaic method for X-Trans do you use?

Reply to: Postprocessing like raw viewers   7 months 2 weeks ago

We ended up applying camera-specific tone curves that match the embedded thumbnail after LibRaw has finished processing it. It seems to work pretty well. We took inspiration for that from how darktable does it. (darktable is open source so you can check the code if you're interested.) I'm guessing the variable contrast mode in FastRawViewer is doing something similar.

Good luck!

Reply to: Postprocessing like raw viewers   7 months 3 weeks ago

Hey, I would also be interested in this topic of how to prepare a "good" visual representation of a RAW file automatically (similar to what FastRawViewer, RawTherapee, etc are doing). Using only dcraw_process() is not enough. I know in the documentation it also says that you should probably write your own algorithm. Is there any literature or open source examples of a "good enough" implementation that produces better results? Especially the exposure seems to be missing in the processing. Take a look at this example, where the top row are original RAW files as seen through FastRawViewer and the bottom row are the images created with dcraw_process(). You can hardly see the difference between the three exposures.

https://www.dropbox.com/s/jvdeu9h0bds9bse/libraw_vs_fastrawviewer.png?dl=0

Reply to: Floating-point DNG: can convert it with libraw on macos, not on linux   7 months 3 weeks ago

Sorry, know nothing about Debian.

There is no problem with your file and LibRaw fetched from github (current public snapshot) and compiled with -DUSE_ZLIB (and linked with -lz)

Reply to: What exactly is pre_mul in libraw_colordata_t?   8 months 2 days ago

I see. Thanks for the prompt reply!

Reply to: What exactly is pre_mul in libraw_colordata_t?   8 months 3 days 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   8 months 4 weeks ago

What version of LibRaw do you use?

Reply to: Building, shipping libraw on macos Big Sur   9 months 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   9 months 3 weeks ago

make -f Makefile.dist
should do the trick

Reply to: DNG recorder   10 months 3 days ago

LibRaw is not about RAW writing, but about reading.

Reply to: Canon AFInfoData mismatch with ExifTool parsed result   10 months 1 week ago

ok, I get it.

Reply to: Canon AFInfoData mismatch with ExifTool parsed result   10 months 1 week 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   10 months 1 week ago

Thanks for your reply and advice.

I've solved the panasonic rw2 issue.

Reply to: Read exif issue from panasonic raw file   10 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   10 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   10 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   10 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   10 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   10 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   10 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/

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