Recent comments

Reply to: Fuji X-Trans sensor Layout   5 years 6 days ago

I'm not sure, that margins are also multiple of 6 in 0.19. Extra effort is needed to analyze (source inspection, may be debugger session), so I won’t do it,

If not, xtrans[][] is for visible area, xtrans_abs[][] is for entire sensor (make sure you use LibRaw-provided margins).

0 is 'channel #0', 1 is 'channel #1', etc. Index to name mapping is in imgdata.idata.cdesc[] string.

Reply to: Fuji X-Trans sensor Layout   5 years 6 days ago

Alex,
Thanks for the clarification. I am currently on 0.19.5 and so wanted to know if the information about margins still holds.

Also, is my understanding of what xtrans represents i.e. 0 -> R, 1 -> G, 2->B correct?

Reply to: Fuji X-Trans sensor Layout   5 years 1 week ago

LibRaw provided margins (left_margin, top_margin) are multiple of 6 (at least in 0.20 beta and in latest snapshots), so xtrans and xtrans_abs are the same.

Reply to: Question for LibRaw installation   5 years 1 week ago

I have had trouble with this for years
Not there
Not where if is suppose to be
Permission problems
Different versions

In the end it is so much easier to use a different compile
Like mingw

Reply to: Accessing Raw Bayer data   5 years 1 week ago

I think that matching pixel by exact values will not work well due to value differences (because of noise, for example).

Reply to: Accessing Raw Bayer data   5 years 1 week ago

Thanks for the quick reply. Then I think I will need to do heavy processing for useful data.
Can I ask your opinion on this matter:
-I am currently working on "image matching with stereo camera". I am looking for away to match the same pixel between left image and right image.
-With the 8 bit data in jpg, sometimes the matching will not be so correct, for example: (pixel of 112.02 will become 112) and (pixel of 111.8 will also become 112). Therefore, they might be considered as a match but it is not true.
Do you think by taking the raw data for processing I can get better matching result? or Raw data are just too noisy for the matching task?
Thanks

Reply to: Missing exif information   5 years 1 week ago

Ok. Now we are sure. Thanks for looking into it.

Reply to: Missing exif information   5 years 1 week ago

Thank you for the sample.
In this sample:
- there is no EXIF/GPS records
- all location information is contained in XMP block

So, LibRaw does not read it

Reply to: Missing exif information   5 years 1 week ago

I just sent you a link to the above address. The image was taken directly from the camera this time so it was not modified by exiftool.

Reply to: Question for accessing raw pixels intensity   5 years 1 week ago

LibRaw postprocessing is very similar to dcraw.c's one, so excellent 'dcraw annotated and outlined' site (https://ninedegreesbelow.com/files/dcraw-c-code-annotated-code.html ) may be useful.

Reply to: Accessing Raw Bayer data   5 years 1 week ago

Short answer: No
RAW values unpacked from RAW file are:
- in linear gamma
- white balance not applied
- black level not subtracted (for most cases; some cameras do black subtraction).

Reply to: Question for accessing raw pixels intensity   5 years 1 week ago

Hi Alex,
Now I am looking for a way to get the process data where you have subtracted the black level, w/ white balance and demosaic, can you please help to explain the procedure? Thanks!

Reply to: Accessing Raw Bayer data   5 years 1 week ago

So, to my knowledge, bayer image would be greyscale (but with 10/12/or 14 bit depending on your camera raw image). Is it correct?
If yes, them if I map those Bayer values into (int)(0 -255), would it be similar to the greyscale.jpg (8 bit) file?
Thanks

Reply to: Question for LibRaw installation   5 years 1 week ago

Hi Alex,
I use the prebuilt library for win 64 and successfully embedded into visual studio. I would like to share my method as following:
1. Extract the binaries for x64.
2. Go into visual project. Open Project Properties, In Configuration Properties:
a. /Debugging/Enviornment: add the path to LibRaw-xxx\bin
b. /C/C++/General/Additional Include Directories: add the path to LibRaw-xxx\
c. /Linker/General/Additional Library Directories: add the path to LibRaw-xxx\lib
/Linker/Input/Additional Dependencies: add libraw.lib and libraw_static.lib
My testing code is following:

#include "libraw/libraw.h"
#include "opencv2/highgui/highgui.hpp"
#include "iostream"
#include "stdio.h"

using namespace std;
using namespace cv;

int main() {
// Let us create an image processor
LibRaw iProcessor;
// Open the file and read the metadata
iProcessor.open_file("D:/[01]Luan_van_thac_si/PROJECT/Non_Cuda/SLIC/SLICSuperPixel/DSC01042.ARW");

// The metadata are accessible through data fields of the class
cout << "Image width = " << static_cast(iProcessor.imgdata.sizes.width)
<< ", Image height = " << static_cast(iProcessor.imgdata.sizes.height) << endl;

waitKey();
return 0;
}

Results: Image width = 6024, Image height = 4024

I hope this answer will help other users and thanks for wonderful library!

Reply to: Missing exif information   5 years 2 weeks ago

You may send link (to dropbox/mediafire/wetransfer) to info@libraw.org to avoid public file exposure.

Reply to: Missing exif information   5 years 2 weeks ago

I think its because of the exiftool. The original IIQ image metadata seems different. Do you know an easy way to tell if its in the exif or xmp ? I will ask my coworker to see if we can create a IIQ with gps and no sensitive info but it may take several days.

Reply to: Missing exif information   5 years 2 weeks ago

Thank you for the file. In this file
- GPS coordinates are recorded in XMP block, not in GPSDirectory EXIF block
- GPSDirectory does not contains coordinates, only references:
| + [GPS directory with 3 entries]
| | 0) GPSVersionID = 2 3 0 0
| | - Tag 0x0000 (4 bytes, int8u[4]):
| | 6218624: 02 03 00 00 [....]
| | 1) GPSLatitudeRef = S
| | - Tag 0x0001 (2 bytes, string[2]):
| | 6218630: 53 00 [S.]
| | 2) GPSLongitudeRef = E
| | - Tag 0x0003 (2 bytes, string[2]):
| | 621863c: 45 00 [E.]

LibRaw does not parse XMP blocks (and no plans for that), so it is unable to extract GPS data from such file.

Reply to: Missing exif information   5 years 2 weeks ago

Thank you for your reply. I don't have any images with GPS from our company that may not be sensitive to post on a forum but I found one having no gps information. I used the exiftool to copy exif metadata from one image (having gps) to this one. Hope that helps.

http://www.mediafire.com/view/i9we9h6jkt9kfum/C0079_3508_238162.IIQ

Reply to: Missing exif information   5 years 2 weeks ago

Followup: we do not have any IIQ files w/ embedded GPS data. Could you please share some samples with us?

Reply to: Missing exif information   5 years 2 weeks ago

Assuming, you're using LibRaw's dcraw_emu sample, not some other app that uses LibRaw:

LibRaw's own TIFF writer routine is very simple, it is used to not depend on additional libraries (e.g. libtiff). So only minimal EXIF data is recorded into output.

LibRaw is opensource, we're open to user contribution. So feel free to implement own TIFF writer (w/ extensive EXIF recording) we will be happy to add it to LibRaw (if you wish so).

Reply to: Question for LibRaw installation   5 years 2 weeks ago

LibRaw 0.19 Win32 binary distribution (downloadable from this site /download page) is built using
nmake -f Makefile.msvc

I do not know what is wrong on your system.

Reply to: Question for accessing raw pixels intensity   5 years 2 weeks ago

Thanks Alex

Reply to: Question for accessing raw pixels intensity   5 years 2 weeks ago

Use imgdata.rawdata.* pointers to access data after unpack()

Reply to: Question for accessing raw pixels intensity   5 years 2 weeks ago

Hi Alex,
Thank you for the quick support.
For now, I think unaltered raw data would be enough for my purpose.

Reply to: Question for accessing raw pixels intensity   5 years 2 weeks ago

I did not understand the question. What values you want to access:
- unaltered raw data (as decoded from RAW file)
- linearized data (black level subtracted)
- processed data (w/ white balance, demosaic, data scaling applied)

?

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