Problem with reading raw 16bit RGB data

Hello

I try to extract 16bit image from RAW camera image [1] using libraw.

The output of libraw is described as 16bit plain bitmap of RGB values.
See http://www.libraw.org/docs/API-CXX-eng.html#dcraw_make_mem_image.

Somehow I’m unable to create an Magick::Image() instance of this extracted 16bit RGB bitmap data using the following code :

// „image“ is a structure returned from libraw containing the data of the extracted image
Magick::Blob blob( image->data, image->data_size ); // „data_size“ is 61011696
Magick::Image img;
img.size( Magick::Geometry(image->width,image->height) ); // „width“ is 3908, „height“ is 2602
img.depth( image->bits ); // „bits“ is 16
img.magick( "RGB" );
img.read( blob );

After read() the call to isValid() returns true.
Saving this image to a file succeeds, but results in unrecognizable image waste !?

img.magick("TIF");
img.write(„test.tif“);

I saved the intermediate image data of libraw to a file „test.rgb“ [2] and tried the following

$ gm identify -size 3908x2602 test.rgb 
test.rgb RGB 3908x2602+0+0 DirectClass 16-bit 58.2Mi 0.000u 0:01

Using the libraw function LibRaw::dcraw_ppm_tiff_writer() from the same extracted image data does result in a proper tif image [3].
Thus I assume that the general functionality of extracting the image from the camera RAW image works.

Any hint appreciated to help me finding out what I did wrong using GraphicsMagick.

[1] Camera RAW image: https://www.dropbox.com/s/c6j5udiupkq5otm/01.cr2?dl=0
[2] Saved 16bit RGB bitmap: https://www.dropbox.com/s/p5ijmy5k4sje0nw/01.rgb?dl=0
[3] Thumbnail of image saved with libraw: https://www.dropbox.com/s/42vy8knt56obxl2/01.cr2.jpg?dl=0





 
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