MATLAB: Fit a plane to 3D data from image

Question

Hello,

I have an image, I, where

>> whos I
  Name         Size                Bytes  Class    Attributes
  I         2056x2464            5065984  uint8  

I plotted the surface using surf:

  surf(double(I))

which displays this:

Now I would like to fit this surface to a plane. So I think I need to use something like

  fit([x, y], z, 'ax+by+c')

but I can't figure out how to format the x,y,z input data using my image. Does anyone know how to do this?

Thanks,

Answer 1

You have to form vectors of x,y,z the same size. Also i suggest you to reduce your data

[m,n] = size(I);
[X,Y] = meshgrid(1:m,1:n);
    % get every 10 000th point
X = X(1:1e4:end)';
Y = Y(1:1e4:end)';
Z = I(1:1e4:end)';
F = fit([X,Y],Z,fittype);