Greyscale calibration overlay

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Greyscale calibration overlay

Michael Doube
Hi all

I have a small feature request that could make use of overlays: a
greyscale calibration bar.

At the moment we make these by creating a new image of the same bit
depth as the original, say 200 x 20 pixels in size, filled with "ramp".
  Then multiply by the maximum value you want to display with Process >
Math > Multiply, and copy-paste into the original.

The advantage of this approach is that the scalebar gets the same LUT
and W&L as the original, but the disadvantages are that you can't move
the bar once pasted, it's destructive to the original and if you have a
stack or hyperstack you have to paste it into all the slices one by one.

I tried adding a ramp image as an overlay to a 32-bit image which had
the fire LUT, but the overlay was insensitive to both the underlying
image's LUT and W&L.

Michael
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Re: Greyscale calibration overlay

Michael Schmid
Hi Michael,

we have Analyze>Tools>Calibration bar; it duplicates the image image  
and adds the calibration bar. So it is not destructive to the  
original image, but it is no overlay. Anyhow, I think it is fine for  
presenting the final result, or do you need a calibration bar while  
still working with an image?

Michael
________________________________________________________________

On 19 May 2010, at 15:05, Michael Doube wrote:

> Hi all
>
> I have a small feature request that could make use of overlays: a  
> greyscale calibration bar.
>
> At the moment we make these by creating a new image of the same bit  
> depth as the original, say 200 x 20 pixels in size, filled with  
> "ramp".  Then multiply by the maximum value you want to display  
> with Process > Math > Multiply, and copy-paste into the original.
>
> The advantage of this approach is that the scalebar gets the same  
> LUT and W&L as the original, but the disadvantages are that you  
> can't move the bar once pasted, it's destructive to the original  
> and if you have a stack or hyperstack you have to paste it into all  
> the slices one by one.
>
> I tried adding a ramp image as an overlay to a 32-bit image which  
> had the fire LUT, but the overlay was insensitive to both the  
> underlying image's LUT and W&L.
>
> Michael
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Re: Greyscale calibration overlay

Michael Doube
Michael,

As you say, that feature is fine if you are creating a 2D figure for
publication, but you cannot explore the original data while
simultaneously viewing a calibration.  I have in mind in particular the
3D thickness images that result from Local Thickness.

Michael

> Hi Michael,
>
> we have Analyze>Tools>Calibration bar; it duplicates the image image
> and adds the calibration bar. So it is not destructive to the
> original image, but it is no overlay. Anyhow, I think it is fine for
> presenting the final result, or do you need a calibration bar while
> still working with an image?
>
> Michael
> ________________________________________________________________
>
> On 19 May 2010, at 15:05, Michael Doube wrote:
>
>> Hi all
>>
>> I have a small feature request that could make use of overlays: a
>> greyscale calibration bar.
>>
>> At the moment we make these by creating a new image of the same bit
>> depth as the original, say 200 x 20 pixels in size, filled with
>> "ramp".  Then multiply by the maximum value you want to display
>> with Process>  Math>  Multiply, and copy-paste into the original.
>>
>> The advantage of this approach is that the scalebar gets the same
>> LUT and W&L as the original, but the disadvantages are that you
>> can't move the bar once pasted, it's destructive to the original
>> and if you have a stack or hyperstack you have to paste it into all
>> the slices one by one.
>>
>> I tried adding a ramp image as an overlay to a 32-bit image which
>> had the fire LUT, but the overlay was insensitive to both the
>> underlying image's LUT and W&L.
>>
>> Michael


--
Dr Michael Doube  BPhil BVSc PhD MRCVS
Research Associate
Department of Bioengineering
Imperial College London
South Kensington Campus
London  SW7 2AZ
United Kingdom