[Vv] Window Level Fusion Slider

[Simon Rit]

This is blending in the opengl sense and we had a lot of trouble to
have a correct overlay for complementary colors (when you do vv
image1.mhd --overlay image2.mhd).
Normally, the blending is done using this formula:
  color = alpha*color1 +(1-a) color2
where alpha is between 0 and 1.
Our workaround was to use the maximum of the two colors, but this is
done by channel.
If you manage to have another solution, we are very interested... but
we don't see how to do it (at least with opengl). Maybe vtkBlendImages
is a good solution?
Let us know if you succeed!
Simon

PS: I forgot in my previous answer, you can now parse fusion from cmd
line: vv image1.mhd --fusion image2.mhd

On Thu, Sep 16, 2010 at 8:34 AM, Rajamani, Kumar (GE Global Research)
<Kumar.Rajamani at ge.com> wrote:
> Dear Simon, Joel
>
> While using the fusion feature, I realized that the slider
> Changes the opacity of the background image (The combined image
> Opacity is changed)
>
> I would like to have a functionality where the opacity slider
> Changes the opacity of the overlay only
> The background image should not be altered and should be always visible
> The extent of overlay should only be altered by the fusion slider
> Is this change possible ? Where could this change be  done ?
>
> I have tried vtkBlendImages but without success
>
> Warm Regards
> Kumar
>
>
>
> Dear Kumar,
> Wrt to the w/l of the fusion image, I totally agree and that's why the
> guy that developed this functionality has added specific text boxes for
> the w/l of the fusion image. If you open an image and add a fusion
> image, go to the overlay tab and you can set the w/l of the overlay
> image. Therefore, the w/l of the image and it's overlay are totally
> independent.
> Let me know if you feel that it's not enough, Simon
>
> On Mon, Sep 13, 2010 at 12:39 PM, Rajamani, Kumar (GE Global Research)
> <Kumar.Rajamani at ge.com> wrote:
>> Dear Simon
>> Thanks for the update regarding the window/level functionality
>>
>> I will do a update and then check its functionality.
>>
>> There could also be potential issues if the W/L ranges of the base
>> image And the W/L of the overlay image are very disparate This might
>> require some grey level mapping before the overlays are done
>>
>> I would like to know your thoughts regarding this I shall test it with
>
>> this version and let you know my results
>>
>> Warm Regards
>> Kumar
>>
>>
>