Error using lazysnapping，Expected input number 3, foreground, to be integer-valued.

Why is there a problem with the third input parameter of "lazysnapping"? I think it is an integer value.

RGB = imread('peppers.png');
L = superpixels(RGB,500); % 分块，主要是加速图像处理
[h,w,c] = size(RGB);
% figure
% BW = boundarymask(L);
% imshow(imoverlay(RGB,BW,'cyan'),'InitialMagnification',67)


figure
imshow(RGB)
h1 = drawpolyline('Color','green'); % 代表前景
roiPoints1 = h1.Position;
h2 = drawpolyline('Color','blue');%代表背景
roiPoints2 = h2.Position;
foregroundInd = sub2ind([h,w],roiPoints1(:,2),roiPoints1(:,1));
backgroundInd = sub2ind([h,w],roiPoints2(:,2),roiPoints2(:,1));

% roi = zeros(size(RGB,1),size(RGB,2),'uint8');
% roi(roiPoints1(:,2),roiPoints1(:,1)) = 255;
BW = lazysnapping(RGB,L,foregroundInd,backgroundInd);

% BW = grabcut(RGB,L,roi);
figure
imshow(BW)

maskedImage = RGB;
maskedImage(repmat(~BW,[1 1 3])) = 0;
figure;
imshow(maskedImage)

Error using lazysnapping

Expected input number 3, foreground, to be integer-valued.

Error in lazysnapping>validateInputs (line 248)

validateattributes(foreground,validMaskTypes,{'nonnan','nonsparse', ...

Error in lazysnapping (line 158)

[foregroundInd,backgroundInd,is3D] = validateInputs(A,L,foreground,background);

Error in faceCropID (line 20)

BW = lazysnapping(RGB,L,foregroundInd,backgroundInd);

Answer 1

[cui,xingxing]

I have found the problem, "position" is a decimal, it needs to be an integer.

roiPoints1 = floor(h1.Position);
roiPoints2 = floor(h2.Position);