Open DNG Image File

Hi, can I know the way to access and open DNG image file using Matlab? Is this the correct way? TQ...

imdata=imread('ABC.dng'); image(imdata)

Answer 1

[Walter Roberson]

imread() will not be able to handle it properly. Please read http://blogs.mathworks.com/steve/2011/03/08/tips-for-reading-a-camera-raw-file-into-matlab/

Answer 2

[Superb]

Yeah...Thanks...I've try my previous code...it only get a blurry image...After that I found another topic which is the same as Walter link...But After I use imtool(cfa), it shows me a black and white image(quite black)...not sure whether it's a correct image I Should obtained from original image which is in Color...can anyone help explain? TQ...

[Walter Roberson]

imread() would only get you the thumbnail. You have to go through many more steps to get the real image.

[Superb]

Thanks...I tried this code...but it give me a very dark image...

info = imfinfo('IMG.dng')

info.SubIFDs{1}

warning off MATLAB:tifflib:TIFFReadDirectory:libraryWarning

t = Tiff('IMG.dng','r');

offsets = getTag(t,'SubIFD');

setSubDirectory(t,offsets(1));

cfa = read(t);

close(t);

imtool(cfa)

Is that a correct way? TQ...

[John]

What's the photometric interpretation of the image?

[Superb]

This is the 2 I try...and the last one I use was using the "2" below...don't know whether it's a correct choice...since "1" will only get Thumbnail of the image...very blur(small size)...so i try "2", but "2" will be very dark but in a big size...

1. info = imfinfo('IMG.dng')

PhotometricInterpretation: 'RGB'

2. info.SubIFDs{1}

PhotometricInterpretation: 'CFA'

[John]

I was kind of thinking it was going to be CFA. It's raw sensor data. I do not know a lot about it, but you might consult the TIFF/EP specification for more information about it.