Recent comments

Reply to: sample images of 2x2meshes and or mazes (non-libraw question)   7 years 4 months ago

Here is the sample of AHD maze: https://picturecode.cachefly.net/photoninja/images/demosaic_before.jpg

Your blue dot artifacts are very different from that.

Reply to: LibRaw Visual Studio Problem   7 years 4 months ago

I know this is old, but 17barski, do you know what specifically you changed or set things to? I'm having the same basic problem where I set dcraw_emu to "Set as Startup Project", compiled everything, saw that dcraw_emu.exe and libraw.dll are in the debug folder, and still get errors saying that the files don't exist. Thanks

Reply to: Problems with msvc 2015 x64 build   7 years 4 months ago

Found it. Mea culpa.

I've added the path to the old libraw 0.17 include files. Removed it and it now works.

But awsome how fast you did reply! :)

Reply to: Problems with msvc 2015 x64 build   7 years 4 months ago

Yeah. I've also did your test (same image), it produces a 16bit ppm.
I guess I need to clean up my code and see where this behaviour comes from.

Reply to: Problems with msvc 2015 x64 build   7 years 4 months ago

Sorry, no MSVC 2015 on hands, just tried with MSVC 2013:
call "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat" x64
nmake -f Makefile.msvc

After that:
mem-image -4 -6 filename.cr2

filename.cr2.ppm (16 bit, linear) was produced, looks OK

Reply to: LibRaw 0.18 released   7 years 4 months ago

Sure! Thanks

Reply to: LibRaw 0.18 released   7 years 4 months ago

http://www.libraw.org/docs should be updated then to remove the LibRaw license.

Reply to: LibRaw 0.18 released   7 years 4 months ago

Thanks!

Reply to: Using Magenta Filter for Shooting With a dSLR Camera Under the Daylight   7 years 5 months ago

WB settings does not change raw data, so you may use any in-camera setting.

Reply to: Using Magenta Filter for Shooting With a dSLR Camera Under the Daylight   7 years 5 months ago

what if a manual WB is chosen and a -magenta is entered (i don't think most of calibrated in CC)? will this give a similar result?

for example, Sony will allow such a compensation. i have already, through my raw processing, set this as my standard, as i shot at one temperature with -magenta, and then adjust the proper temperature during raw processing.
At a first glance, presuming the filter blocks only the green channel, this means that the red and the blue channels should be exposed one stop better. However, the blue and red channels are sensitive to a pretty wide range of spectrum. That's why the actual per channel exposures were changed less than that, as it is obvious when looking at the white balance coefficients.

Reply to: Maximum/saturation pixel value   7 years 5 months ago

And if data is scaled to 8 bit somewhere, your result looks correct.

coloir.maximum is in RAW data domain, so for 14-bit camera it is about 16000.
imgdata.image[], after processing, is in 0..64k range.
your luminocity calculation, in first assumption, is in same range as imdata.image, so 64k.

So your jpeg generation code will show upper two stops of image as 'overflow'

Reply to: Maximum/saturation pixel value   7 years 5 months ago

Not so. It looks like you've divided data by 256 (than recover it back?). This step is missing
In your code:

unsigned int luminosity = ((unsigned int)iProcessor.imgdata.image[i][0] * 2 + (unsigned int)iProcessor.imgdata.image[i][1] * 3 + (unsigned int)iProcessor.imgdata.image[i][2])/6;
		data[i] = luminosity;

data should be in 16bit (64k) range.
Next step:

jpegData[i] = unsigned char((data[i]*255)/iProcessor.imgdata.color.maximum);

Data is upscaled to 24 bit?

Reply to: Maximum/saturation pixel value   7 years 5 months ago

The data array is set in my first example. It is just an approximation of the luminosity of each pixel. (2*red+3*green_blue)/6.

This link should show you the output of the above as jpeg files. You can see the integer overflow in the overexposed clouds https://1drv.ms/f/s!AgLCmsxNxVV_jelOf_MIR7MeGcsXvQ

Reply to: Maximum/saturation pixel value   7 years 5 months ago

imgdata.image is indeed scaled in LibRaw::scale_colors() call

For your test: what contained in data array?

Reply to: Maximum/saturation pixel value   7 years 5 months ago

Hmm, It seems to me that processed data are not being scaled to the 0-65535 range. In fact the data that are not saturated fall into the range 0 - colour.maximum, only saturated values are larger than color.maximum.

Is there a way I can upload an image to the forum? I have generated a greyscale jpeg from the data vector in my code above using

std::vector<unsigned char> jpegData(data.size());
for(size_t i=0; i<data.size(); ++i)
	jpegData[i] = unsigned char((data[i]*255)/iProcessor.imgdata.color.maximum);

The ouput shows the buffer overrun from conversion to unsigned char very clearly.

Phil

Reply to: Maximum/saturation pixel value   7 years 5 months ago

color.maximum is 'maximum data value permitted by data format'.
In some cases, real maximum is smaller.
There is color.data_maximum field, but it is filled /based on real data/ on raw2image (or dcraw_process) stage, so not available just after unpack().

In your example you compare raw data maximum (so, data range of raw data) with processed values.
This is not correct, because output data are scaled to use full data range (16 bit).

Reply to: Get White balance multipliers   7 years 5 months ago

Thank-you Alex
I have just loaded up an image and I see the WB_Coeffs array. Elements 1, 3, 4, 10, 11 and 14 are filled, which presumably correspond to the 6 options of my EOS 40D (daylight, cloudy, shade, tungsten, fluorescent, flash). That's everything I needed.

Thanks for the excellent info.

Phil

Reply to: Get White balance multipliers   7 years 5 months ago

1st:

With LibRaw 0.18 (currently in Beta1, Beta2 to be published soon),
in-camera WB multipliers are extracted into
imgdata.color.WB_Coeffs[256][4];
and
imgdata.colr.WBCT_Coeffs[64][5];

This extraction is made for all RAWs with embedded color presets, not only Canons.

1st array (WB_Coeffs) is indexed with EXIF Colorsource, so to get, for example, D65 preset, you need to inspect WB_Coeffs[21] for non-zero values.
2nd array (WBCT_Coeffs) is filled from 0 to 63:
WBCT_Coeffs[i][0] is color temperature (from camera settings)
and
WBCT_Coeffs[i][1..4] are WB coeffs.

There is no automated procedure to copy these values into processing, so one needs to examine array data (or, simply, fill WB drop-down with these values), than copy needed WB Coeffs into
imgdata.params.user_mul[] to use on dcraw_process() stage.
So, processing sequence is
LibRaw::open_file();
LibRaw::unpack();
... examine WB_Coeffs/WBCT_Coeffs
.. copy needed into user_mul
LibRaw::dcraw_process();

(and, sure, you may call dcraw_process() multiple times without unpack() of same file)

2nd:
WB Coeffs to CCT and back is not very complex (look into Adobe DNG SDK sources for sample code), but results of this procedure depends on color profile and camera calibration data used.
So, calculated CCT/Tint will, most likely, not compatible with other programs (or, even, with in-camera WB setting by CCT).

Reply to: Orientation issue (EOS 10D)   7 years 6 months ago

Now I have my fix looks like:

switch (imgdata.sizes.flip)
{
case 3://0011
case 180:
metaData.flip = Meta_data::Flip_180;
break;
case 5://0101
case 270:
metaData.flip = Meta_data::Flip_90CCW;
break;
case 6://0110
case 90:
metaData.flip = Meta_data::Flip_90CW;
break;

Reply to: Orientation issue (EOS 10D)   7 years 6 months ago

From first lines of raw2image_start (called by _ex):

  if (O.user_flip >= 0)
    S.flip = O.user_flip;
 
  switch ((S.flip+3600) % 360)
    {
    case 270:  S.flip = 5;  break;
    case 180:  S.flip = 3;  break;
    case  90:  S.flip = 6;  break;
    }

So:
flip/user_filp are bit-field. But if someone has specified user_flip in degrees it will work OK.

Specifically for CIFF (CRW) format camera sets rotation angle, not Orientation tag. This value is preserved after open_datastream (looks like we need to fix it for all cases in 0.18?)

Reply to: Orientation issue (EOS 10D)   7 years 6 months ago

For most camera which I have used the flip field means "bit-field" before actually processing (unpack()/raw2image_start()). But for EOS 10D this flag means the rotation angle. So, I would prefer not to start processing but get meaning of this field: is it bit-field or angle. Is it possible to know if it was corrected before?

Reply to: Orientation issue (EOS 10D)   7 years 6 months ago

Also, flip is 'bit-field', it converted from degree rotation to bits in raw2image_start() if not corrected before

Reply to: Orientation issue (EOS 10D)   7 years 6 months ago

imgdata.image (and rawdata.*) and imgdata.sizes are always in 'sensor dimensions', so it is alwasy unrotated and rotation/mirroring is read/set via flip/user_flip.

Rotation/mirroring is performed on output phase:
dcraw_ppm_tiff_writer()
or
dcraw_make_mem_image()

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