I know that my Canon camera's raw offset is meant to be 2048, however often libraw reports slightly different values in rawdata.color.black like 2044 for instance. Which one is more accurate? The reported value seems like it might be prone to being influenced by noise. Can the true offset vary this way or should I take libraw's reported value as an approximation of the ideal value? And if libraw's value is to be trusted then why is that?
I want to make pixel to pixel matching between RAW and JPEG for Sony a6000. The RAW Size 6048x4024 but the JPEG is 6000x4000. How the clipping is done(I know is it is sony propriety if any info available)? How I could recreate the RAW so that it could match to JPEG size? Not only Size but want to ensure the pixels are exactly matched with the JPEG.
For the image data generated from "dcraw_make_mem_image()", I see it is of "uchar" type according to the documentation:
"
unsigned char data[] Data array itself.
Should be interpreted as RGB triplets for bitmap type and as JPEG file for JPEG type.
"
For 16-bit image, when I need to convert "uchar" data array to "float" data array, the "original" values won't stay so the image won't convert correctly.
I am just wondering are there any functions that return "floating-point" data array after "dcraw_process()" is called.
How does libraw estimate the scene illuminant in order to calculate the Chromatic Adaptation Matrix (CAT) to get from that scene illuminant to the output_color encoding white point?
If I want to use camera white balance, should I use "-w" as "dcraw" originally has? It does not seem to be in "dcraw_emu". I can add it back if "-w" still has the same meaning.
Also, does "pre_mul" contain the white balance values either read from meta data or calculated by libraw?
If the white balance values can not be found in the meta data, I understand libraw will calculate them. If it is true, is there method that I can call to ask libraw to not calculate white balance?
Just wondering if I set "output_color" to 0, does "libraw" generate "Camera RAW" RGB data? if so, since it does not apply the color profile, do I need to set other parameters such as "use_camera_wb" or "no_auto_bright"?
this is more of a dcraw question than a libdraw, but I am hoping someone can help anyway.
I was wondering if somebody can post a sample image with 2x2 mesh or maze that was noted in dcraw manual that may happen. I recently tried to port dcraw to plan9. After making a few code changes, I was able to compile it. It works ok except when I use the AHD option where I get some dot patterns. I am still trying to trouble shoot it, but I was thinking if I new what a 2x2 mesh or maze look like it would help me in the process.
I am having some trouble determining the maximum or saturation level for my pixels, I thought it was LibRaw::imgdata.color.maximum, however I find in some cases that after processing I have values bigger than this value. My code is below:
Hi
I would like to do white balance corrections with libRaw. It looks to me like there is built in functionality to use the rggb multipliers specified by the camera during the shot or use auto based on full frame or a rectangle.
I am trying to work out where to get the multipliers for other conditions. It seems like in my Canon CR2 raw files there is a list of multipliers for daylight, shade, tungsten, etc. Is there a way to extract these or directly use them with libRaw? If so is the method general (i.e. will it work for other file formats and camera models)?
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