VolumeViewer ScaleFactors not working in R2018b

I can display a volume (V) using

volumeViewer (V)

but I have problem display the volume using scalefactorr

scaleFactors = [1 1 1]

volumeViewer (V,'ScaleFactors', scaleFactors)

Error using volumeViewer

Too many input arguments.

Answer 1

[Ameer Hamza]

ScaleFactor was not present in R2018b: https://www.mathworks.com/help/releases/R2018b/images/ref/volumeviewer-app.html?searchHighlight=volumeviewer. It was introduced in R2019a. So an upgrade will to be the only option to use this feature.

[Ameer Hamza]

bk_norwich's comments, posted as answer, moved here:

Thank you Ameer. I wasted hours on this.

Unfortunately it is no longer possible for me to upgrade. I take it that there is no other ways of introducing scaling into R2018b?

[Ameer Hamza]

Try the following code, this should work in R2018b

x = ones(100, 100, 100);
sf = [2, 0.1, 1]; % scale factor.

[r, c, p] = size(x);
[Xg, Yg, Zg] = ndgrid(linspace(0,1,c), linspace(0,1,r), linspace(0,1,p));
[Xg_, Yg_, Zg_] = ndgrid(linspace(0,1,sf(1)*c), linspace(0,1,sf(2)*r), linspace(0,1,sf(3)*p));
x_ = interpn(Xg, Yg, Zg, permute(x, [2 1 3]), Xg_, Yg_, Zg_);

volumeViewer(permute(x_, [2 1 3]));

[Ameer Hamza]

bk_norwich's comments, posted as answer, moved here:

Dear Ameer

I appreciate your help. I am getting an error and wonder if you could help please.

The scale factor in my code below is:

scaleFactor = [0.7813 0.7813 5.0000]

I have adaopted your code below:

dicomHeader = appData.DicomHeaderInfo;

sliceThickness = dicomHeader.SliceThickness;

pixelSpacing = dicomHeader.PixelSpacing;

scaleFactor = [pixelSpacing(1) pixelSpacing(2) sliceThickness];

startFrame = str2num(get(appData.hTxtStartFrame,'String'));

endFrame = str2num(get(appData.hTxtEndFrame,'String'));

%originalVolume = appData.ImageBitmaps

newVolume =appData.ImageBitmaps(:,:,startFrame:endFrame);

[r, c, p] = size(newVolume);

[Xg, Yg, Zg] = ndgrid(linspace(0,1,c), linspace(0,1,r), linspace(0,1,p));

[Xg_, Yg_, Zg_] = ndgrid(linspace(0,1,scaleFactor(1)*c), linspace(0,1,scaleFactor(2)*r), linspace(0,1,scaleFactor(3)*p));

newVolume_ = interpn(Xg, Yg, Zg, permute(newVolume, [2 1 3]), Xg_, Yg_, Zg_);

volumeViewer(permute(newVolume_, [2 1 3]));

I get the following error

Error using griddedInterpolant

Sample values must be a single or double array.

Error in interpn (line 153)

F = griddedInterpolant(X{:}, V, method,extrap);

Error in historad>ViewVolume_CallBack (line 1553)

newVolume_ = interpn(Xg, Yg, Zg, permute(newVolume, [2 1 3]), Xg_, Yg_, Zg_);

Error while evaluating UIControl Callback.

[Ameer Hamza]

Can you check the class of newVolume

class(newVolume)

[Ameer Hamza]

bk_norwich's comments, posted as answer, moved here:

Hi Ameer

Here is the class of new volume:

ans =

'int16'

The array values are singed CT Hounsfield values containing both positive and negative values.

[Ameer Hamza]

Convert it to double datatype

newVolume = double(appData.ImageBitmaps(:,:,startFrame:endFrame));

[bk_norwich]

Dear Ameer

I cannot thank you more. It worked! You are a star.

[Ameer Hamza]

I am glad to be of help! :)

Answer 2

[bk_norwich]

Hi Ameer

Here is the class of new volume:

ans =

'int16'

The array values are singed CT Hounsfield values containing both positive and negative values.

[Ameer Hamza]

Instead of adding a new answer, the correct way is to add a comment to my original answer. It will help keep the discussion organized.