How to use image labeled resulted from Image labeler App (black image) to calculate jaccard Index?

I used pixel label from image labeler App and after I finished labeling I used Export to file . Then I opened the file which created called PixelLabeData and I found the labeled image is totally black and the label not shown, I undertsand that I have to use the following code to let label appear

figure;

[i, m] = imread('Label_1.png');

imshow(i,m)

but then I want to use this labeled image in the following equation to calculate jaccrad index, but the image is totally black

A = logical(imread('7001-236.png'));

BW_groundTruth =logical(imread('Label_1.png'));

similarity = jaccard(squeeze(A(:,:,1)), BW_groundTruth)

similarity =

0.0925 because label image is black

so how to fix it?

[yasmin ismail]

@Stephen23@Torsten@Image Analyst