MATLAB: Error using label2rgb…

Question

This error was occurred when I was testing the Example of the " Multilevel image thresholds using Otsu's method" in Matlab 2015a. Can you please tell me why this error occurred and how to solve this?

link to the example : –

openExample('images/CompareThresholdingEntireImageVersusPlanebyplaneThresholExample')
>> I = imread('circlesBrightDark.png');
>> imshow(I)
Warning: Image is too big to fit on screen; displaying at 67% 
> In images.internal.initSize (line 71)
  In imshow (line 305) 
>> axis off
>> title('Original Image')
>> thresh = multithresh(I,2);
>> seg_I = imquantize(I,thresh);
>> RGB = label2rgb(seg_I);
Error using label2rgb
Expected input number 1, L, to be two-dimensional.
Error in label2rgb>parse_inputs (line 128)
validateattributes(L,{'numeric','logical'}, ...
Error in label2rgb (line 49)
[label,map,zerocolor,order,fcnflag] = parse_inputs(varargin{:});

Answer 1

You need to convert your image to greyscale to use that function.