OK, sorry for this dummy question indeed.
So my question is now how libraw know the constant factor to apply to normalize to 16bits ?
Sorry if it is a dummy question again.
Could you please explain 12 vs 14 bit difference for Sony cRAW format:
1) Data stored in 8-bit per pixel overall (16-pixel blocks, 11-bit base value, 7-bit deltas)
2) After decompression: 11 bit non-linear data
3) After linearization curve applied: ??bit data with data range 0...~17000
File format is the same for 12-bit ADC cameras (e.g. A700), real 14-bit ADC (e.g. Sony A7r) and 14-bit ADC in 12-bit mode (A7R in electronic shutter mode).
OK, opened it in phothoshop.
I do not see 2x2 patterns (typical for bayer CFA). If non-bayer CFA is used, than LibRaw/FRV Custom Camera would not help, it targeted for bayer CFA only.
I've now checked also images from the 800D and 77D models:
DNG-Converter converts to 6024x4022, and DCRAW reports 6024x4020.
And I found that with both models the additional top rows of the DNGs are black!
So the correct size seems to be 6024x4020.
Since there is no chance to have a common and correct size, I think it might be the best to not change anything.
Typical today raw converter (e.g. Adobe's and/or in-camera JPEG generator, I'm not familiar with rawtherapee) applies S-shaped curve (with different parameters for different cameras/different ISO setting on same camera/different other setting e.g. DLO on Nikon cameras).
LibRaw/dcraw default rendering does histogram shift to the right only.
The rawtherapee rendering and the 'out of the camera' jpeg are nearly identical, whereas the dcraw rendering is too dark. Is this normal and expected? (my libraw implementation gives the same result as dcraw).
In my small collection of RAWs from various cameras, some of them are fine after libraw conversion, some have brightness and color problems (i.e. dark and/or faded). The Nikon D850 is one of the problem cases.
The following produces images almost identical to the JPEGs:
$ rawtherapee-cli -d -t -b8 -Y -c
Fotoxx is a photo editor and collection manager for Linux.
Usage: Load RAW files using libraw, edit using Fotoxx (with full bit depth), save as jpeg/png/tiff (8/16 bit color).
Fotoxx home: https://kornelix.net
imgdata.sizes.raw_width/raw_height are not enough?
Thanks a lot, that was what I was looking for.
Many thanks
imgdata.color.maximum variable holds maximum data range (this value is not black-level-subtracted)
OK, sorry for this dummy question indeed.
So my question is now how libraw know the constant factor to apply to normalize to 16bits ?
Sorry if it is a dummy question again.
Could you please explain 12 vs 14 bit difference for Sony cRAW format:
1) Data stored in 8-bit per pixel overall (16-pixel blocks, 11-bit base value, 7-bit deltas)
2) After decompression: 11 bit non-linear data
3) After linearization curve applied: ??bit data with data range 0...~17000
File format is the same for 12-bit ADC cameras (e.g. A700), real 14-bit ADC (e.g. Sony A7r) and 14-bit ADC in 12-bit mode (A7R in electronic shutter mode).
I do not know. Please try and let us know
is recommended to use LibRaw::open_buffer() to open file or better to use directly LibRaw::open_datastream()
Both ways should work.
Thank you very much Alex ;-) !
And followup:
dcraw_emu/dcraw.c also accepts user_flip in degrees (e.g. 90, 270, or -90), to handle this too, add these lines before snippet in previous message:
if (flip > 89 || flip < -89)
{
flip = (flip + 720) % 360;
switch (flip)
{
case 90: return 6;
case 180: return 3;
case 270: return 8;
default: return 1;
}
}
Here is small code snippet that may help you in flip->orientation conversion:
int arr[10] = { 1, 1, 2, 4, 3, 5, 8, 6, 7, 1 };
return arr[qBound(0, flip + 1, 9)]; // add 1 and set limit to 9 to handle out of range values
Ah thank you Alex, it was a bit confusing, but I guess this is due to my own assumptions ;-) ...
Kind regards,
Mabula
Yes, libraw imgdata.sizes.flip and tiff:Orientation tag are different.
OK, opened it in phothoshop.
I do not see 2x2 patterns (typical for bayer CFA). If non-bayer CFA is used, than LibRaw/FRV Custom Camera would not help, it targeted for bayer CFA only.
The file sample you provide *mostly* contains 0xFF bytes (not all bytes are 0xff, but ~62% from beginning is).
It is not easy to analyze such samples, do you have another one (with some image with well-known object with known non-neutral colors).
Generally, CustomCamera may work for FRV, but we need known colors to guess CFA.
I've now checked also images from the 800D and 77D models:
DNG-Converter converts to 6024x4022, and DCRAW reports 6024x4020.
And I found that with both models the additional top rows of the DNGs are black!
So the correct size seems to be 6024x4020.
Since there is no chance to have a common and correct size, I think it might be the best to not change anything.
Thank you for your feedback and attention to details. Case closed.
I'm afraid it's more basic than magic.
Thanks. That's what I needed to know. I feared there was some magic I was missing.
Typical today raw converter (e.g. Adobe's and/or in-camera JPEG generator, I'm not familiar with rawtherapee) applies S-shaped curve (with different parameters for different cameras/different ISO setting on same camera/different other setting e.g. DLO on Nikon cameras).
LibRaw/dcraw default rendering does histogram shift to the right only.
Here is your sample with +1 correction with highlights compression: https://www.dropbox.com/s/fsimdf5alou55qy/Screenshot%202019-01-25%2020.2...
Are you saying that 03.nef is underexposed and the dcraw rendering is normal?
Then the question remains, how did rawtherapee know how to compensate?
Here is a Sony A7 raw, the corresponding 'out of the camera' jpeg, and renderings by dcraw and rawtherapee:
https://kornelix.net/downloads/DSC00574.ARW
https://kornelix.net/downloads/out-of-the-camera.jpg
https://kornelix.net/downloads/dcraw.tif
https://kornelix.net/downloads/rawtherapee.tif
The rawtherapee rendering and the 'out of the camera' jpeg are nearly identical, whereas the dcraw rendering is too dark. Is this normal and expected? (my libraw implementation gives the same result as dcraw).
commands:
dcraw -w -T DSC00574.ARW
rawtherapee-cli -t -b8 -d -c DSC00574.ARW
Source web page for the above raw and jpeg:
https://www.dpreview.com/sample-galleries/6769434587/sony-a7-iii-sample-...
The second one (_03.nef) is underexposed: https://www.dropbox.com/s/2jmz4niipiv552v/Screenshot%202019-01-25%2017.4...
(gray square on girl's cheek is RawDigger sample, average green/red is ~5EV below saturation point).
After exposure correction the image is more-or-less OK: https://www.dropbox.com/s/g76re8v887rnfen/Screenshot%202019-01-25%2017.4...
Yes the 1st one is not bad, only a small loss in color.
Please check the 2nd one.
Checked the 1st one:
dcraw -w -T (and irfanview screenshot of resulting tiff file): https://www.dropbox.com/s/ynkb94latus6n55/Screenshot%202019-01-25%2017.0...
Embedded JPEG viewed via FastRawViewer: https://www.dropbox.com/s/wbc4ifjizd9dzm4/Screenshot%202019-01-25%2017.0...
This is screnshots from screen, so in (my) display colorspace (near-sRGB)
I do not see any big problems here, although LibRaw's color profile may differ from Nikon's one
Thanks for your help.
Here are some raw images and their corresponding jpeg images.
These are all from https://www.photographyblog.com/previews/nikon_d850_photos
(most of the photos on this web page have the same issue).
In my small collection of RAWs from various cameras, some of them are fine after libraw conversion, some have brightness and color problems (i.e. dark and/or faded). The Nikon D850 is one of the problem cases.
The following produces images almost identical to the JPEGs:
$ rawtherapee-cli -d -t -b8 -Y -c
https://www.photographyblog.com/previews/nikon_d850_photos
Nikon D850 RAW images
https://img.photographyblog.com/reviews/nikon_d850/photos/nikon_d850_01.nef
https://img.photographyblog.com/reviews/nikon_d850/photos/nikon_d850_03.nef
https://img.photographyblog.com/reviews/nikon_d850/photos/nikon_d850_09.nef
https://img.photographyblog.com/reviews/nikon_d850/photos/nikon_d850_42.nef
Corresponding JPEG images from the camera
https://img.photographyblog.com/reviews/nikon_d850/photos/nikon_d850_01.jpg
https://img.photographyblog.com/reviews/nikon_d850/photos/nikon_d850_03.jpg
https://img.photographyblog.com/reviews/nikon_d850/photos/nikon_d850_09.jpg
https://img.photographyblog.com/reviews/nikon_d850/photos/nikon_d850_42.jpg
Could you please provide some (properly exposed) samples with 'problematic' color/brightness?
Fotoxx is a photo editor and collection manager for Linux.
Usage: Load RAW files using libraw, edit using Fotoxx (with full bit depth), save as jpeg/png/tiff (8/16 bit color).
Fotoxx home: https://kornelix.net
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