Recent comments

Reply to: libraw/dcraw_emu crushes shadows and turns them blue compared to dcraw with exact same settings   2 weeks 2 days ago

It is hard to discuss anything related to RAW processing without having the sample file(s)

Reply to: Unable to read RAW image from Agfa Photo DC-833m sensor   2 weeks 5 days ago

Thank you for the files, downloaded.

These files are uncompressed 16-bit sensor dumps (for example, 3264*2448 = 7990272 pixels x 2 bytes per pixel = 15980544 bytes, exact size of file provided).
Also, according to manual (easy to find), camera does not provide raw recording, so raw files are some kind on debug mode or something like that.

I'm unable to see any meaningful image in these samples, it looks like flat field shot, or something like that. So it is not possible to determine if white/black level set correctly or not. Please provide something with well known subject.

Sensor dumps are supported via pre-defined table of known file sizes, to enable half-size image support apply this patch:
diff --git a/src/metadata/identify.cpp b/src/metadata/identify.cpp
index 251f97b2..eab078c0 100644
--- a/src/metadata/identify.cpp
+++ b/src/metadata/identify.cpp
@@ -247,7 +247,8 @@ void LibRaw::identify()
{ 10134608, 2588, 1958, 0, 0, 0, 0, 9, 0x94, 0, 0, "AVT", "F-510C" },
{ 10134620, 2588, 1958, 0, 0, 0, 0, 9, 0x94, 0, 0, "AVT", "F-510C", 12 },
{ 16157136, 3272, 2469, 0, 0, 0, 0, 9, 0x94, 0, 0, "AVT", "F-810C" },
- { 15980544, 3264, 2448, 0, 0, 0, 0, 8, 0x61, 0, 1, "AgfaPhoto", "DC-833m" },
+ { 3995136, 1632, 1224, 0, 0, 0, 0, 8, 0x61, 0, 1, "AgfaPhoto", "DC-833m" },
+ { 15980544, 3264, 2448, 0, 0, 0, 0, 8, 0x61, 0, 1, "AgfaPhoto", "DC-833m" },
{ 9631728, 2532, 1902, 0, 0, 0, 0, 96, 0x61, 0, 0, "Alcatel", "5035D" },
{ 31850496, 4608, 3456, 0, 0, 0, 0, 0, 0x94, 0, 0, "GITUP", "GIT2 4:3" },
{ 23887872, 4608, 2592, 0, 0, 0, 0, 0, 0x94, 0, 0, "GITUP", "GIT2 16:9" },

Or use 'custom camera API'

Reply to: Unable to read RAW image from Agfa Photo DC-833m sensor   2 weeks 5 days ago

Hi Alex,
I have fixed the link permissions. Sorry about that.

https://drive.google.com/drive/folders/1X1Tdy744XXb2AaMvE9ZIwsNRqjoYbFUe....

The files are quite large and sometimes these email filters block files. Do let me know if you still have trouble accessing the files.

Regards,
Dinesh

Reply to: Unable to read RAW image from Agfa Photo DC-833m sensor   3 weeks 4 hours ago

Unfortunately, the link you provided is not for everyone, I've requested access

Alternatively you can attach the samples to E-mail targeted to info@libraw.org

Reply to: Is the COLOR function exposed in the C API?   3 weeks 5 days ago

Nevermind, of course, is is prefixed, I don't know why I didn't see it: libraw_COLOR Sorry for the noise!

Reply to: Sony ilce 7rm3a Support to be added   4 weeks 1 day ago

7r iii A is supported in the recent snapshot

Reply to: Pixel data manipulation   4 weeks 1 day ago

Unaltered ('as unpacked') pixel values are stored in imgdata.rawdata array(s)

samples/unprocessed_raw.cpp example writes (unaltered) data to TIFF file, probably this is code example you're looking for

Reply to: LibRaw 0.20 supported cameras   1 month 1 day ago

ilce 7rm3a - sony alpha 7r iiia is actually Almosen same like ilce 7rm3 - sony alpha 7r iii

Reply to: iPhone 11 Halide DNG gives black image.   1 month 1 week ago

Btw, there is zero guarantee that in a DNG that ColorMatrix2 corresponds to D65 illuminant, or that there is one corresponding to a D65 illuminant at all. It is just a recommendation, not a requirement.

Reply to: iPhone 11 Halide DNG gives black image.   1 month 1 week ago

Not sure it is good idea (unless specified explicitly by library user via some flag?)
cam_xyz contains built-in data (from colordata.cpp), dng_color filled by DNG tags, not sure DNG data should always overwrite built-in data.

Reply to: imgdata.sizes.raw_pitch is only available after unpacking?   1 month 1 week ago

Yes, raw_pitch field is filled only on unpack() phase: this data field describes layout of data in imgdata.rawdata.* array(s), not in input file and it is not known before unpack().

Reply to: iPhone 11 Halide DNG gives black image.   1 month 1 week ago

Thank you. I looked in to this more, it turns out the libraw->rawdata.color.cam_xyz field is blank with DNG images. I had to look at libraw->rawdata.color.dng_color

Sorry about the mistaken post!

I have a suggestion: Maybe put DNG's ColorMatrix2 (Daylight) in to the cam_xyz field? It might reduce confusion for some developers.

I am using build from latest source code from github.

Reply to: How to compute White Balance from cam_mul?   1 month 1 week ago

In colour science CCT is derived from xy. xy calculation depends on the colour transform, raw to XYZ. This transform is not one-to-one because raw data isn't colorimetric. Different companies use different colour transforms for the same camera model. Say, the camera and ACR report different CTs for the same shot.
Your best bet is to shoot a camera at each CT setting, compile a table of CTs vs. wb coeffs, and interpolate.

Reply to: How to compute White Balance from cam_mul?   1 month 1 week ago

What I want to do is to give user a Color temperature slider that needs to start with the color temp of the photo (say 5000K) and let him move in the range of say 2000-10000K.

So how do I compute this using the various data obtained in libraw_colordata_t? I thought cam_mul is a start?

Reply to: How to compute White Balance from cam_mul?   1 month 1 week ago

White balance is not measured in Kelvins.

Reply to: How to enable multiple processors support for macOS?   1 month 2 weeks ago

There is no omp.h file in standard toolchain

Reply to: How to enable multiple processors support for macOS?   1 month 2 weeks ago

This is no longer true. Standard Apple Toolchain works with OpenMP. Just add -Xclang -fopenmp to the compile flags.

I have to add -DLIBRAW_FORCE_OPENMP in the Makefile.dist in order for it work for standard Apple Toolchain.

That aside, but how do I control the number of threads to use? It seems be always the same as the number of logical processors.

Reply to: How to enable multiple processors support for macOS?   1 month 2 weeks ago

Probably we need to remove comment 'need to recheck': rechecked and, yes, it will not work in standard Apple-provided environment

Reply to: How to enable multiple processors support for macOS?   1 month 2 weeks ago

If you're speaking about:
#elif (defined(__APPLE__) || defined(__MACOSX__)) && defined(_REENTRANT)
/* Latest XCode works with OpenMP, need to recheck here */
#undef LIBRAW_USE_OPENMP

This is not bug, but specially added because standard Apple toolchain does not support OpenMP

For other toolchains one may use -DLIBRAW_FORCE_OPENMP to enable this #if-branch:
#if defined(LIBRAW_FORCE_OPENMP)
...

Reply to: How to enable multiple processors support for macOS?   1 month 2 weeks ago

Just follow the instructions on this link:

https://mac.r-project.org/openmp/

I grabbed the OpenMP dylib there and it compiles fine. No need to download another version of llvm.

In fact, I finally got LibRaw to work. There is a bug in Libraw_types.h in which it failed to detect -fopenmp when compiling via Xcode. Fixing that LibRaw compiles just fine using Xcode 12.4 with OpenMP support.

The question I have now is: how to control the number of threads during decode? It seems the #pragma parallel will cause the number of threads creation the same as the number of logical processor. I don't want that many. Is there a way I can alter that during runtime before calling unpack()?

Reply to: How to enable multiple processors support for macOS?   1 month 2 weeks ago

I'm unable to build openmp app with Xcode/clang because of omp.h missing. find / -name omp.h returns nothing.

So:
1) It is not possible to compile LibRaw with openmp using standard Apple tools (12.4 and 12.5)
2) If you was able to compile it: that means you have omp.h from some other build tools, we're unable to provide support in that case. You may add some #error preprocessor directives into LibRaw sources near #pragma omp to make sure it compiled with openmp or not.

Reply to: How to enable multiple processors support for macOS?   1 month 2 weeks ago

Xcode 12.4 actually works with -fopenmp, you need to add -Xclang option just before it.

I made a small sample code like this:

int main(int argc, const char * argv[]) {
omp_set_num_threads(8);
#pragma omp parallel
#pragma omp critical
NSLog(@"Greetings from thread %d", omp_get_thread_num());
return NSApplicationMain(argc, argv);
}

And I get this on the console:

2021-10-20 16:23:46.653740-0700 Test[14661:304853] Greetings from thread 0
2021-10-20 16:23:46.653954-0700 Test[14661:304941] Greetings from thread 1
2021-10-20 16:23:46.653985-0700 Test[14661:304943] Greetings from thread 3
2021-10-20 16:23:46.654015-0700 Test[14661:304942] Greetings from thread 2
2021-10-20 16:23:46.654045-0700 Test[14661:304944] Greetings from thread 4
2021-10-20 16:23:46.654069-0700 Test[14661:304947] Greetings from thread 7
2021-10-20 16:23:46.654085-0700 Test[14661:304946] Greetings from thread 6
2021-10-20 16:23:46.654102-0700 Test[14661:304945] Greetings from thread 5

My problem now is with libraw:

In the Makefile.dist, I uncommented CFLAGS+=-fopenmp and I added -Xclang to it, so it looks like:

CFLAGS+=-Xclang -fopenmp

It compiles fine, but when I linked my project, it'll link even I did not have libomp.dylib. So libraw is not really compiled with OpenMP support with the CFLAGS line above.

So what else is missing?

Reply to: How to enable multiple processors support for macOS?   1 month 2 weeks ago

Apple's clang (from XCode 12.4) refuses -fopenmp option, so OpenMP is not supported by this (standard macOS) compiler

If you use another compiler/runtime please refer your OpenMP runtime docs about "How do I control the number of CPU cores...."

Reply to: Generating ColorMatrix1 from input data   1 month 2 weeks ago

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

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