Apply window width and level on 8 bit dicom image which was converted from 16 bit image - DICOM

This is a discussion on Apply window width and level on 8 bit dicom image which was converted from 16 bit image - DICOM ; Dear friends, I Have a problem with applying window width and level to a 16 bit dicom images. For display, I am converting this 16 bit to 8 bit. Before conversion, I am applying window width and level to this ...

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Thread: Apply window width and level on 8 bit dicom image which was converted from 16 bit image

  1. Apply window width and level on 8 bit dicom image which was converted from 16 bit image

    Dear friends,

    I Have a problem with applying window width and level to a 16 bit dicom
    images.

    For display, I am converting this 16 bit to 8 bit.

    Before conversion, I am applying window width and level to this 16 bit
    image pixel.
    It is working fine.

    I would like to know, how can I apply further window width and level to
    the new 8 bit image pixel.

    Is there any algorithm or mathematical ratios for convert the window
    width
    and level values accordingly , so that it can be applicable to 8 bit
    image.

    Thanks and regards
    Alvin


  2. Re: Apply window width and level on 8 bit dicom image which was converted from 16 bit image


    alvin schrieb:

    > Dear friends,
    >
    > I Have a problem with applying window width and level to a 16 bit dicom
    > images.
    >
    > For display, I am converting this 16 bit to 8 bit.
    >
    > Before conversion, I am applying window width and level to this 16 bit
    > image pixel.
    > It is working fine.
    >
    > I would like to know, how can I apply further window width and level to
    > the new 8 bit image pixel.
    >
    > Is there any algorithm or mathematical ratios for convert the window
    > width
    > and level values accordingly , so that it can be applicable to 8 bit
    > image.
    >
    > Thanks and regards
    > Alvin


    Why would you want to do this? You cut down the grayscale range
    dramatically in the 16 to 8bit convertion step, thats why this step
    should be the last before displaying the image.

    My application uses the following pipeline for mouse "windowing":

    Mouse move event
    |
    rescale 16 bit buffer with new win width and center via slope/intercept
    equation
    |
    Downscaling from 16/12/10 bit to 8 bit
    | |
    Copy new 8bit buffer into windows DIP

    As you can see, rescaling is done before downscaling.


    regards,
    Andreas


  3. Re: Apply window width and level on 8 bit dicom image which was converted from 16 bit image

    Thanks Andreas for the reply.
    This is exactly what I am doing now.
    But I am facing a problem with images having large size, for example,
    some CR iamges width x height = 2048 x 2048
    In this case,
    applying rescale 16 bit buffer with new win width and center via
    slope/intercept
    +
    Downscaling to 8 bit

    is taking lots of time.

    Please provide a solution.

    Thanks and Regards
    Alvin


  4. Re: Apply window width and level on 8 bit dicom image which was converted from 16 bit image

    Hello Alvin,

    Apply a better algo for window width or window level. Try to use some
    low level row wise or col wise image manipulations function calls
    rather than by evey pixel.

    The end user might not always use a high resolution monitir that is 1K
    by 1K. Under conventional monitor you can resize the original image 16
    bit image to the current view resolution and then apply ww and wl. I am
    doing the same i am getting good results on a low end workstation. My
    customers max resolution is less that 1200 by 800.

    with regards
    Rady

    alvin wrote:
    > Thanks Andreas for the reply.
    > This is exactly what I am doing now.
    > But I am facing a problem with images having large size, for example,
    > some CR iamges width x height = 2048 x 2048
    > In this case,
    > applying rescale 16 bit buffer with new win width and center via
    > slope/intercept
    > +
    > Downscaling to 8 bit
    >
    > is taking lots of time.
    >
    > Please provide a solution.
    >
    > Thanks and Regards
    > Alvin



  5. Re: Apply window width and level on 8 bit dicom image which was converted from 16 bit image

    Hello Alvin,

    Apply a better algo for window width or window level. Try to use some
    low level row wise or col wise image manipulations function calls
    rather than by evey pixel.

    The end user might not always use a high resolution monitir that is 1K
    by 1K. Under conventional monitor you can resize the original image 16
    bit image to the current view resolution and then apply ww and wl. I am
    doing the same i am getting good results on a low end workstation. My
    customers max resolution is less that 1200 by 800.

    with regards
    Rady

    alvin wrote:
    > Thanks Andreas for the reply.
    > This is exactly what I am doing now.
    > But I am facing a problem with images having large size, for example,
    > some CR iamges width x height = 2048 x 2048
    > In this case,
    > applying rescale 16 bit buffer with new win width and center via
    > slope/intercept
    > +
    > Downscaling to 8 bit
    >
    > is taking lots of time.
    >
    > Please provide a solution.
    >
    > Thanks and Regards
    > Alvin



  6. Re: Apply window width and level on 8 bit dicom image which was converted from 16 bit image

    Hello Rady,
    Thanks for the reply.

    Could you please tell me how can I reduce size of a large image pixel
    to its corrsponding
    small image according to resolution?

    Is there any algorithm for doing this?

    Thanks and regards
    Alvin


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