RAW processing

All about RAW processing

Are my LibRaw / rawpy settings giving me true unprocessed sensor data for CIE 1931(XYZ) color space conversion?

Submitted by valiklord on

I’m working on a project to measure object brightness from photographs as accurately as possible.
The plan:

Load RAW sensor data.

Extract pixels from a region of interest and average them.

Convert to XYZ color space and use the Y channel as brightness.

Since I’m using Python, I rely on rawpy (a wrapper for LibRaw). My main concern is whether the way I open/process RAW files preserves true, unprocessed sensor values, so that my XYZ conversion is valid and not influenced by hidden processing.

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disappeared dcraw functionality

Submitted by Berend on

Hi,

I have been using dcraw a lot and now trying LibRaw because I have a camer that uses cr3 files. In LibRaw I am missing two main featerus that used to be pasrt of DcRaw.

1. The possibility to keep original capture date when converting to tiff (-z in DcRaw)
2. The option to assign a camera icc profile after linear conversion ( -p )

Have those options been removed for a specifif reason?

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Accessing processed image data

Submitted by marekp on

I'm unsure how and where to access processed image data after calling libraw_dcraw_process. I noticed that imgdata.image now has a valid pointer, but looking at the 4channels samples that suggests that this is just raw data (which I can and do currently access via imgdata.rawdata.raw_image). I've also looked at calling libraw_dcraw_make_mem_image which seems to create reasonable values in libraw_processed_image_t (width, height, etc., ) but just has data as a byte array (despite 16bit processed data) length=1 (libraw_types.h has ''unsigned char data[1]" declaration).

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Generic white-balance and color correction when dcraw_process()

Submitted by amir.t on

I am creating a post-processing pipeline that will deal with a large variety of cameras (makes, models, lenses etc...)

All Formats supported by libraw will likely be encountered at some point.

All of the images will, at some point, call dcraw_process().

But, during testing, i have observed that some images tend to come out "dark", and some have "not ideal" white-balancing.

In search for a comparison, i looked at the images using FastRawViewer and they look EXCELLENT there!

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libraw_internal_data access

Submitted by jwkim on

Hi, I'm new user of LibRaw.

I'm wondering can I get access to libraw_internal_data.

For example, in src / postprocessing / postprocessing_utils.cpp, there is a 'convert_to_rgb_loop' function.

And in that function, I can print 'imgdata.idata.colors' but I want to know generated 'libraw_internal_data.output_data.histogram'.

So please let me know whether internal_data is public information or not.

Thank you.

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