LibRaw technical support

Stable LibRaw versions: technical support, errors, API questions

Floating-point DNG: can convert it with libraw on macos, not on linux

Submitted by pvledoux on

Hi,

I have a DNG that I successfully converted with dcraw_emu on Mac OS (libraw 0.20.2 was installed with homebrew).
But on Debian 11, same command is not working (libraw 0.20.2-1), I get an error: cannot unpack file.dng: Corrupted data or unexpected EOF.

I tried to re-compile libraw to be sure that zlib is included, but no luck.

Here is the file: https://www.dropbox.com/s/d7u46lj8tevvjha/22_xav.dng?dl=0

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What exactly is pre_mul in libraw_colordata_t?

Submitted by chiahsing on

Hi,

I am new to raw image processing, and was just playing LibRaw for a couple of weeks. I apologize if this question has been asked before. So, I was trying to read a .CR2 file. In my first version, the image was very green, and I found that it was because I didn't multiply pixels with pre_mul. With a bit of code tracing, I found that pre_mul is calculated (in my case, lossless jpeg decoder) in cam_xyz_coeff() in utils_dcraw.cpp as follow:

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Issue while converting CR3 using draw_emu

Submitted by amanAntstack on

Hi folks,

I am trying to use LibRAW to convert the CR3 files to tiff and then convert the tiff to jpeg using imagemagick. I want to run this as a container on AWS using Fargate (nodejs application).

The process runs perfectly for CR2 files but for CR3 file the tiff file is not getting created and draw_emu is not throwing any error too.

Command used for conversion:

dcraw_emu -6 -T -w -v test.cr3

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Canon AFInfoData mismatch with ExifTool parsed result

Submitted by qdwang on

CR3 file: https://www.dpreview.com/sample-galleries/8035448300/canon-eos-m50-mark-...

I've dumped the HTML analysis file though this: exiftool -htmldump IMG_0993.CR3.

Pls check the png comparison file uploaded below. The Libraw AFInfoData dropped a lot of useful info here.

Thanks~

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Read exif issue from panasonic raw file

Submitted by qdwang on

According to the https://exiftool.org/TagNames/Panasonic.html, the `AFPointPosition` tag id is 0x004d.

But it seems to the PanasonicRaw tags parsing is used in libraw.

Is it possible to access the 0x004d exif data form modern RW2 file without modifying the source code heavily?

Thanks for your great work.

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DigiKam Raw Conversion Output

Submitted by Tarek on

Recently I have stumbled upon DigiKam software which uses intenally Libraw library as a raw conversion engine.
I have tried to convert one of the images I have using DigiKam with all conversion settings disabled/set to default (i.e. gamma 1.0, no auto brightness, camera wb, no expsoure correction) and only I have an input a custom icc profile and output color space set to AdobeRGB. The output looks like this here (https://imgur.com/a/rJ3pS2b)

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LCMS and Libraw Support

Submitted by Tarek on

I have just compiled Libraw with enabling LCMS2 on Win10. From the generated executables it works just fine now and it can profile well. However, I am looking for using it as a dll library in my C++ code, so when I linked the compiled Libraw to my visual studio project I don't seem to be able to apply profiles, just like LCMS is not supported in the API.

Could you please point out if I am missing something? shouldn't Libraw API sees LCMS after compilation ?

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Phase One IIQ decoding

Submitted by t.sawka on

Hello

I'm trying to use LibRaw to decode Phase One IIQ images from two cameras: iXM-100 (not officially supported) and IQ280 (supported). I save results to .tif files and thumbnails to .pnm. I used all default settings.
Code I used:

https://drive.google.com/file/d/1PnbVb2J8jXkoGiOWqEa_n8A5X4-5zGTJ/view?u...

I also tried to use Open Image IO tool (which as I understand uses LibRaw as backend).

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