How to segment a region

I have an image from which I want to extract a region and display it in a separate image . I have written a code but it's displaying an error message.

Below is my code:

I = imread('Intensity1.jpg');
imshow(I)
hold on

mask = false(size(I));
mask(200:400) = true;
visboundaries(mask,'Color','b');

I want to extract the region from 200:400(i.e. only the yellow and green part of the image) and display them separately . But I am shown the following error message:

Error using visboundaries

Expected input number 1, BW, to be two-dimensional.

Error in visboundaries>obtainAndValidateBoundaries (line 236)

validateattributes(B, {'numeric','logical'}, {'2d','real','nonsparse'}, ...

Error in visboundaries>parseInputs (line 185)

boundaries = obtainAndValidateBoundaries(B,first_string);

Error in visboundaries (line 91)

[ax, boundaries, options] = parseInputs(varargin{:});

Error in I2 (line 7)

visboundaries(mask,'Color','b');

Answer 1

[Image Analyst]

Try this

hFig = figure;
subplot(1, 2, 1);
rgbImage = imread('Intensity1.jpg');
imshow(rgbImage)
subplot(1, 2, 2);
croppedImage = rgbImage(200 : 400, :, :);
imshow(croppedImage);

[Warid Islam]

Hi,

That works perfect. Thanks a lot.