Function 'subsindex' is not defined for values of class 'cell'.

Hi, I have tried to run my code which is thresholding and segmentation of a BW image and display each object in the image separately :

clear all
close all
clc
I=imread('brain.jpg');
I=rgb2gray(I);
I2=threshold(I);
cc=bwconncomp(I2,8); 
n=cc.NumObjects;
area= zeros(n,1);
premimeter=zeros(n,1);
majoraxis=zeros(n,1);
minoraxis=zeros(n,1);

    K=  regionprops(cc,'Area','Perimeter','MajorAxisLength','MinorAxisLength'); 
  for i=1:n
      obj=zeros(size(I2));
      obj(cc.PixelIdxList(i))=1;
      figure(i);
      imshow(obj);
      area(i)=K(i).Area;
      premimeter(i)=K(i).Perimeter;
      majoraxis(i)=K(i).MajorAxisLength;
      minoraxis(i)=K(i).MinorAxisLength;
  end

however i got an Err messages says :

(Function 'subsindex' is not defined for values of class 'cell'.

Error in Segmentation (line 17)
    obj(cc.PixelIdxList(i))=1;)

I have checked cc(struct) and checked the PixelIdxList cell,it is defined and nothing wrong with it !! i am not sure what is the wrong in this code!!!

Answer 1

[Stephen23]

The problem is simple: cc.PixelIdxList(i) is a cell array, and cell arrays cannot be used for indexing.

The bxconncomp documentation clearly shows explains that output: " PixelIdxList 1-by-NumObjects cell array where..."

An index must be numeric or logical: it cannot be of class cell, struct, table, ...

To fix this you will have to decide how you want to process the zero or more identified objects. A loop would be the obvious starting point.

Answer 2

[samundeeswari p]

 instead of using this instruction obj(cc.PixelIdxList(i))=1; try this obj(cc.PixelIdxList{i})=1;
 for class cell we need to use {} bracket
am sure this will help you..