how to remove black background of 3D image?

Hi everyone.i only need that 3D image. how to remove black background? i tried to edit the data of my image but it doesn't really works. thanks in advance.

[KSSV]

How the data is?

Answer 1

[jupiter]

Please provide the format of the data, if its in the form of an image or grayscale levels.

[Zaitul]

 here i attached the picture and the code as well. 'stomachgray.tif' is grayscale image

a = imread ('stomachgray.tif');

b = imcrop (a);

mask = zeros(size(b));

mask(100:end-100,100:end-100) = 1;

bw = activecontour(b,mask,1000);

c = im2double(bw); shading flat

d = imgaussfilt3 (c,4);

colormap(copper)

mesh(d.*100)