LibRaw technical support

Stable LibRaw versions: technical support, errors, API questions

Extracting Metadata Without Unpacking RAW Data

Submitted by kennyc on

Is there a way to have libraw extract the metadata from a RAW file without unpacking all the data?

I'm using the libraw plug-in that is part of OpenImageIO. In that plugin, unpack() is called before any of the image properties are read, which causes the property reading to be incredibly slow because unpacking() is slow (relative to just reading the TIFF header in most RAW files.)

https://github.com/OpenImageIO/oiio/blob/master/src/raw.imageio/rawinput...

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Orientation of some Canon files wrong in LibRaw 0.19-Snapshot-20170212

Submitted by asdiele on

Hello!

Using dcraw_emu.exe compiled from the LibRaw 0.19-Snapshot-20170212.

Some Canon files are being displayed with the wrong orientation, they show as landscape when they should be portrait.

Looking at the code I found a place in dcraw_common.cpp with a note saying :

#if 0 /* Canon rotation data is handled by EXIF.Orientation */

If I re-enable that piece of code then the images show correctly. I tried to look around for "EXIF.Orientation" or something like it but couldn't find it.

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Nikon Coolpix P330 - wrong black and white levels

Submitted by netgeek on

Hi guys,

There seems to be a bug in LibRaw 0.19-Snapshot-20170212. To reproduce:

1. Download a Nikon Coolpix P330 raw sample. Here is one website to download from:

http://www.photographyblog.com/reviews/nikon_coolpix_p330_review/sample_...

2. Use dcraw_emu to convert the raw file to TIFF (or some other format). The TIFF image will appear almost completely white.

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dcraw_emu - Brightness Level

Submitted by chris_s on

First, thanks for creating this version of DCRaw. I have been using the original DCRAW as part of a utility I have developed to make it easy to run the NIK Collection standalone. One of the added features is the ability to input RAW files. I needed a way to support Fuji X compressed files and this is probably the best and easiest way to do that. It also seems to be quicker than the original DCRaw.

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0 width and height after processing

Submitted by adsamcik on

Before I run
LibRaw::raw2image() or LibRaw::dcraw_process()

LibRaw::imgdata.sizes contain proper dimensions but after running one or the other the values are 0. Both functions return LIBRAW_SUCCESS (0)

I have no idea how to debug this. All images tested are cr2 and open just fine in other programs including "dcraw_emu.exe".

everything I did is below.

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Fuji X-E2s White Level

Submitted by netgeek on

Hello,

I'm noticing that LibRaw reports a different white level from Adobe's DNG for this camera (and possibly other Fuji cameras too).

Here is one publicly available test image.

http://img.photographyblog.com/reviews/fujifilm_x_e2s/sample_images/fuji...

I converted this image to a DNG using Adobe's DNG converter. The white level stored in the DNG is 16383.

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CR2 to Tiff conversion produces darker image

Submitted by shawnathan007 on

I have a .CR2 image taken by a Canon 80D camera. I'm using LibRaw to convert it to a .TIF. The .TIF which is created is darker than the original .CR2 file (when viewed using Canon's Digital Photo Professional or Irfan View)

I read the contents of the .CR2 file to a buffer, then pass the buffer to this method to convert and save to .TIF:

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