Pink background when using raw2hdr

I am trying to use raw2hdr to generate HDRI of the face of a light source, and I keep getting pink noise overlaying structures in the background. I am not getting any errors during the process. Does anyone know why this might be happening, and if there’s a way around this while still using the raw images? I put the jpegs through photosphere, and the pink noise doesn’t appear, so it seems to be a calculation error in the combination of the raw LDR images.

I work in research, so I can’t post the entire image, but here is a crop of the background to give an idea of what I am seeing.

This may be caused by an issue with dcraw where it doesn’t leave quite enough headroom in white. Try adding “-b 1.2” to the raw2hdr command line, and increase it further if you need to by increments of 0.1. (The default brightness value is 1.1)

I went through and tested different values, but the pink did not go away. Instead, there was in increase in blue noise. @Greg_Ward do you have any other suggestions?

At this point I would have to see your input images to figure out what is going on. You can contact me off-list ( and I’ll see what I can find. If you’re worried about confidentiality, then take photos of something less sensitive with the same problem and I’ll work with those.

Hi Greg and Lia,
I also encountered identical problem when I generated a HDR image using several raw files.

Here’s my code:
raw2hdr -h -w -o output.hdr input1.CR2 input2.CR2 … input15.CR2
The running process was without any errors and warnings, but the rendering was produced with higher pink noises. I know that the “raw2hdr” program is executed based on the “dcraw”, “hdrgen”, and “exiftool” programs. All the programs were derived from the latest released source code. I have also tried some parameters (e.g., -a -e -g -f) in the code line to see how the results would be different, but I still got the similar results.

I don’t know whether you solved the problem or not. I will appreciate any help.


Did you try the same -b option setting? I don’t think @Lia_I ever sent me her images, but the same offer stands for you.

Hi Greg,

I did try different settings for the -b option (i.e., default, 2, 2.2, 2.3, 6, and 8), but the problem was not solved as expected. For example, the pink noises were decreased with the -b option being set from default to 2.2, but they became higher again with the -b option being set to 2.3. The values of 6 and 8 would make the images totally white. It seems that such an option cannot effectively improve the quality of the image. I will attach the results for your reference.

-b_default (-b default)
-b_2 (-b 2)

(-b 2.2)
(-b 2.3)

Some information derived from the process is shown as below:
Loading Canon EOS 80D image from input1.CR2 …
Scaling with darkness 0, saturation 16383, and
multipliers 1.832031 1.000000 1.707031 1.000000
Building histograms…
Writing data to standard output …
1 image files updated
Whether the values of the saturation and the multiplier would affect the results?


Can you upload your originals, somewhere? There must be something really wrong going on, here…

Even a single .CR2 file might be useful.