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From: Ganga on 28 Oct 2005 04:51
Original CT image(grayscale image) is reproduced as color image(pink
with green background) from Matlab. Do you have any idea how it comes
or how should we get grayscale image as original CT(X-ray) image?
Also, shall we get those CT images in the about same depth as
original(depth of -1000 to +1000 Hounsfield unit)? Looking for
response.
From: Jeff Mather on 28 Oct 2005 11:33
Ganga wrote:
> Original CT image(grayscale image) is reproduced as color image(pink
> with green background) from Matlab. Do you have any idea how it comes
> or how should we get grayscale image as original CT(X-ray) image?

Are you saying that a grayscale image comes out of DICOMREAD as a
colorful image (with the wrong colors)? If you can send me a file, I'll
take a look at it.


> Also, shall we get those CT images in the about same depth as
> original(depth of -1000 to +1000 Hounsfield unit)? Looking for
> response.

Some DICOM images use the "RescaleSlope" and "RescaleIntercept" values
to map device units to display units. These specify the coefficients
"a" and "b" in "y = a*x + b". Use DICOMINFO to get these values.


Jeff Mather
Image Processing Team
The MathWorks, Inc.

From: Matthew Crema on 28 Oct 2005 18:15
Jeff Mather wrote:
> Ganga wrote:
>
>> Original CT image(grayscale image) is reproduced as color image(pink
>> with green background) from Matlab. Do you have any idea how it comes
>> or how should we get grayscale image as original CT(X-ray) image?
>
>
> Are you saying that a grayscale image comes out of DICOMREAD as a
> colorful image (with the wrong colors)? If you can send me a file, I'll
> take a look at it.
>
>
> > Also, shall we get those CT images in the about same depth as
> > original(depth of -1000 to +1000 Hounsfield unit)? Looking for
> > response.
>
> Some DICOM images use the "RescaleSlope" and "RescaleIntercept" values
> to map device units to display units. These specify the coefficients
> "a" and "b" in "y = a*x + b". Use DICOMINFO to get these values.
>
>
> Jeff Mather
> Image Processing Team
> The MathWorks, Inc.
>

Maybe you are just plotting with the wrong colormap?

load mri
image(D(:,:,1)) % That's a lot of colors!

% Plot as a grayscale image instead of using the default (jet) colormap

colormap gray
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