Converted CR2 Is Darker Than Thumbnail

[SkyeHoefling]

I have a CR2 raw image that I am trying to convert to a jpeg and the image that is being written is much darker than what is in the embedded thumbnail or outputs generated from dcraw.exe. I am wondering if there are additional settings that need to be toggled to match the behavior.

This image was handed to me by the QA team on the project I am working on. No one knows where it came from so it could be a bad sample set, but I am not sure how to identify that.

dcraw.exe generated tiff

Magick.NET generated tiff

Embedded thumbnail extracted using dcraw.exe as jpeg

Here is my code

var settings = new MagickReadSettings
{
  Defines = new DngReadDefines
  {
    UseCameraWhitebalance = true,
    DisableAutoBrightness = true
  },
  Format = MagickFormat.Jpeg
};

using (var image = new MagickImage(file, settings))
{
  image.Write(outputPath);
}

The CR2 file is too large to upload to GitHub so I created a public link to download from OneDrive

• Sample1.cr2

I've been researching the documentation and this GitHub and have found some useful tips such as using the DngReadDefines but can't seem to get this image to convert as expected.

[dlemstra]

Adding the file zipped:
sample1.001.zip
sample1.002.zip
sample1.003.zip

[dlemstra]

I don't understand what you are trying to achieve? What is the output image that you are looking for? When you don't set any of the dng read defines you will get the same output image as dcraw?

[SkyeHoefling]

How do you best simulate the behavior of dcraw with magick. I was expecting magick to generate a result that matches my first screenshot above, but it generates the 2nd screenshot above. This creates a darker image than what I was expecting. I am probably not sending the right parameters when loading the image. If I use this same file directly with LibRaw or Dcraw I get the correct image.

[dlemstra]

When I read the image without any DngReadDefines I get the same image as "dcraw.exe generated tiff". Have you tried that?