MATLAB: I try to use bwlabel, but there error that i can’t fix

>> BW=imread('b.jpg');
>> L=bwlabel(BW);
Error using bwlabel
Expected input number 1, BW, to be two-dimensional.

…

please help

Best Answer

jpg files are almost always RGB images even if they look like black and white. You need to rgb2gray() the content and perhaps im2bw() the result.

Related Solutions

MATLAB: Number of Object in binary image

Try this:

bw = imread('bw.png');
if ndims(bw) > 1
	bw = bw(:,:,1);
end
% Threshold
bw = bw > 128;
subplot(1, 2, 1);
imshow(bw, []);
% Fill holes
bw = imfill(bw, 'holes');
% Get areas
props = regionprops(bw, 'Area');
sortedAreas = sort([props.Area], 'descend')
% Looks like we need to throw away any blobs less than 1000 pixels or so
bw = bwareaopen(bw, 1000);
subplot(1, 2, 2);
imshow(bw);
% Count the blobs
[labeledImage, numBlobs] = bwlabel(bw);
fprintf('Found %d shapes.\n', numBlobs);

MATLAB: Thin the boundary of objects of black & white images

Use imerode.

From Matlab documentation:

IM2 = imerode(IM,SE) erodes the grayscale, binary, or packed binary image IM, returning the eroded image IM2. The argument SE is a structuring element object or array of structuring element objects returned by the strel function.

Example:

Erode a binary image with a disk structuring element.

originalBW = imread('circles.png');  
se = strel('disk',11);        
erodedBW = imerode(originalBW,se);
imshow(originalBW), figure, imshow(erodedBW)

Best Answer

Related Solutions

MATLAB: Number of Object in binary image

MATLAB: Thin the boundary of objects of black & white images

Related Question