Crack detection on concrete
Hi, i have problem in measuring the length and width the crack image.
i have follow the code but it only measure straight line (endpoint). I want the measurement by following the crack pattern. Please help me on this.
%load image
path=imgetfile();
originalImage1=imread(path);
imshow(originalImage1);
%image to grayscale
originalImage = rgb2gray(originalImage1);
figure
imshow(originalImage);
%treshold
thresholdValue = 100;
binaryImage = originalImage > thresholdValue;
binaryImage = imfill(binaryImage, ‘holes’);
hold on;
% maxYValue = ylim;
% line([thresholdValue, thresholdValue], maxYValue, ‘Color’, ‘r’);
% annotationText = sprintf(‘Thresholded at %d gray levels’, thresholdValue);
% text(double(thresholdValue + 5), double(0.5 * maxYValue(2)), annotationText, ‘FontSize’, 10, ‘Color’, [0 .5 0]);
% text(double(thresholdValue – 70), double(0.94 * maxYValue(2)), ‘Background’, ‘FontSize’, 10, ‘Color’, [0 0 .5]);
% text(double(thresholdValue + 50), double(0.94 * maxYValue(2)), ‘Foreground’, ‘FontSize’, 10, ‘Color’, [0 0 .5]);
figure
imshow(binaryImage);
% bw = bwareaopen(binaryImage,100,8);
bw= bwareaopen(binaryImage, round(0.1*numel(binaryImage)));
figure
imshow(bw)
g=bwmorph(bw,’clean’);
figure
imshow(g);
% %labeled image (on hold)
labeledImage = bwlabel(g,4);
figure
imshow(labeledImage, []);
%colored label image
coloredLabels = label2rgb (labeledImage, ‘hsv’, ‘k’, ‘shuffle’);
figure
imshow(coloredLabels);
axis image;
%blobmeasurement
blobMeasurements = regionprops(labeledImage, originalImage, ‘all’);
numberOfBlobs = size(blobMeasurements, 1);
figure
imshow(originalImage);
axis image; % Make sure image is not artificially stretched because of screen’s aspect ratio.
hold on;
boundaries = bwboundaries(binaryImage);
numberOfBoundaries = size(boundaries, 1);
for k = 1 : numberOfBoundaries
thisBoundary = boundaries{k};
plot(thisBoundary(:,2), thisBoundary(:,1), ‘g’, ‘LineWidth’, 2);
end
hold off;
% Measure the area
measurements = regionprops(labeledImage, ‘Area’);
boundaries = bwboundaries(binaryImage);
numberOfBoundaries = size(boundaries, 1);
for blobIndex = 1 : numberOfBoundaries
thisBoundary = boundaries{blobIndex};
x = thisBoundary(:, 2); % x = columns.
y = thisBoundary(:, 1); % y = rows.
% Find which two bounary points are farthest from each other.
maxDistance = -inf;
for k = 1 : length(x)
distances = sqrt( (x(k) – x) .^ 2 + (y(k) – y) .^ 2 );
[thisMaxDistance, indexOfMaxDistance] = max(distances);
if thisMaxDistance > maxDistance
maxDistance = thisMaxDistance;
index1 = k;
index2 = indexOfMaxDistance;
end
end
% Find the midpoint of the line.
xMidPoint = mean([x(index1), x(index2)]);
yMidPoint = mean([y(index1), y(index2)]);
longSlope = (y(index1) – y(index2)) / (x(index1) – x(index2))
perpendicularSlope = -1/longSlope
% Use point slope formula (y-ym) = slope * (x – xm) to get points
y1 = perpendicularSlope * (1 – xMidPoint) + yMidPoint;
y2 = perpendicularSlope * (columns – xMidPoint) + yMidPoint;
% Get the profile perpendicular to the midpoint so we can find out when if first enters and last leaves the object.
[cx,cy,c] = improfile(binaryImage,[1, columns], [y1, y2], 1000);
% Get rid of NAN’s that occur when the line’s endpoints go above or below the image.
c(isnan(c)) = 0;
firstIndex = find(c, 1, ‘first’);
lastIndex = find(c, 1, ‘last’);
% Compute the distance of that perpendicular width.
perpendicularWidth = sqrt( (cx(firstIndex) – cx(lastIndex)) .^ 2 + (cy(firstIndex) – cy(lastIndex)) .^ 2 );
% Get the average perpendicular width. This will approximately be the area divided by the longest length.
averageWidth = measurements(blobIndex).Area / maxDistance;
% Plot the boundaries, line, and midpoints over the two images.
% Plot the boundary over the gray scale image
subplot(2, 2, 3);
plot(x, y, ‘y-‘, ‘LineWidth’, 3);
% For this blob, put a line between the points farthest away from each other.
line([x(index1), x(index2)], [y(index1), y(index2)], ‘Color’, ‘r’, ‘LineWidth’, 3);
plot(xMidPoint, yMidPoint, ‘r*’, ‘MarkerSize’, 15, ‘LineWidth’, 2);
% Plot perpendicular line. Make it green across the whole image but magenta inside the blob.
line([1, columns], [y1, y2], ‘Color’, ‘g’, ‘LineWidth’, 3);
line([cx(firstIndex), cx(lastIndex)], [cy(firstIndex), cy(lastIndex)], ‘Color’, ‘m’, ‘LineWidth’, 3);
% Plot the boundary over the binary image
subplot(2, 2, 4);
plot(x, y, ‘y-‘, ‘LineWidth’, 3);
% For this blob, put a line between the points farthest away from each other.
line([x(index1), x(index2)], [y(index1), y(index2)], ‘Color’, ‘r’, ‘LineWidth’, 3);
plot(xMidPoint, yMidPoint, ‘r*’, ‘MarkerSize’, 15, ‘LineWidth’, 2);
% Plot perpendicular line. Make it green across the whole image but magenta inside the blob.
line([1, columns], [y1, y2], ‘Color’, ‘g’, ‘LineWidth’, 3);
line([cx(firstIndex), cx(lastIndex)], [cy(firstIndex), cy(lastIndex)], ‘Color’, ‘m’, ‘LineWidth’, 3);
message = sprintf(‘The longest line is red.nPerpendicular to that, at the midpoint, is green.nMax distance for blob #%d = %.2fnPerpendicular distance at midpoint = %.2fnAverage perpendicular width = %.2f (approximatelynArea = %d’, …
blobIndex, maxDistance, perpendicularWidth, averageWidth, measurements(blobIndex).Area);
fprintf(‘%sn’, message);
uiwait(helpdlg(message));
end
hold off;Hi, i have problem in measuring the length and width the crack image.
i have follow the code but it only measure straight line (endpoint). I want the measurement by following the crack pattern. Please help me on this.
%load image
path=imgetfile();
originalImage1=imread(path);
imshow(originalImage1);
%image to grayscale
originalImage = rgb2gray(originalImage1);
figure
imshow(originalImage);
%treshold
thresholdValue = 100;
binaryImage = originalImage > thresholdValue;
binaryImage = imfill(binaryImage, ‘holes’);
hold on;
% maxYValue = ylim;
% line([thresholdValue, thresholdValue], maxYValue, ‘Color’, ‘r’);
% annotationText = sprintf(‘Thresholded at %d gray levels’, thresholdValue);
% text(double(thresholdValue + 5), double(0.5 * maxYValue(2)), annotationText, ‘FontSize’, 10, ‘Color’, [0 .5 0]);
% text(double(thresholdValue – 70), double(0.94 * maxYValue(2)), ‘Background’, ‘FontSize’, 10, ‘Color’, [0 0 .5]);
% text(double(thresholdValue + 50), double(0.94 * maxYValue(2)), ‘Foreground’, ‘FontSize’, 10, ‘Color’, [0 0 .5]);
figure
imshow(binaryImage);
% bw = bwareaopen(binaryImage,100,8);
bw= bwareaopen(binaryImage, round(0.1*numel(binaryImage)));
figure
imshow(bw)
g=bwmorph(bw,’clean’);
figure
imshow(g);
% %labeled image (on hold)
labeledImage = bwlabel(g,4);
figure
imshow(labeledImage, []);
%colored label image
coloredLabels = label2rgb (labeledImage, ‘hsv’, ‘k’, ‘shuffle’);
figure
imshow(coloredLabels);
axis image;
%blobmeasurement
blobMeasurements = regionprops(labeledImage, originalImage, ‘all’);
numberOfBlobs = size(blobMeasurements, 1);
figure
imshow(originalImage);
axis image; % Make sure image is not artificially stretched because of screen’s aspect ratio.
hold on;
boundaries = bwboundaries(binaryImage);
numberOfBoundaries = size(boundaries, 1);
for k = 1 : numberOfBoundaries
thisBoundary = boundaries{k};
plot(thisBoundary(:,2), thisBoundary(:,1), ‘g’, ‘LineWidth’, 2);
end
hold off;
% Measure the area
measurements = regionprops(labeledImage, ‘Area’);
boundaries = bwboundaries(binaryImage);
numberOfBoundaries = size(boundaries, 1);
for blobIndex = 1 : numberOfBoundaries
thisBoundary = boundaries{blobIndex};
x = thisBoundary(:, 2); % x = columns.
y = thisBoundary(:, 1); % y = rows.
% Find which two bounary points are farthest from each other.
maxDistance = -inf;
for k = 1 : length(x)
distances = sqrt( (x(k) – x) .^ 2 + (y(k) – y) .^ 2 );
[thisMaxDistance, indexOfMaxDistance] = max(distances);
if thisMaxDistance > maxDistance
maxDistance = thisMaxDistance;
index1 = k;
index2 = indexOfMaxDistance;
end
end
% Find the midpoint of the line.
xMidPoint = mean([x(index1), x(index2)]);
yMidPoint = mean([y(index1), y(index2)]);
longSlope = (y(index1) – y(index2)) / (x(index1) – x(index2))
perpendicularSlope = -1/longSlope
% Use point slope formula (y-ym) = slope * (x – xm) to get points
y1 = perpendicularSlope * (1 – xMidPoint) + yMidPoint;
y2 = perpendicularSlope * (columns – xMidPoint) + yMidPoint;
% Get the profile perpendicular to the midpoint so we can find out when if first enters and last leaves the object.
[cx,cy,c] = improfile(binaryImage,[1, columns], [y1, y2], 1000);
% Get rid of NAN’s that occur when the line’s endpoints go above or below the image.
c(isnan(c)) = 0;
firstIndex = find(c, 1, ‘first’);
lastIndex = find(c, 1, ‘last’);
% Compute the distance of that perpendicular width.
perpendicularWidth = sqrt( (cx(firstIndex) – cx(lastIndex)) .^ 2 + (cy(firstIndex) – cy(lastIndex)) .^ 2 );
% Get the average perpendicular width. This will approximately be the area divided by the longest length.
averageWidth = measurements(blobIndex).Area / maxDistance;
% Plot the boundaries, line, and midpoints over the two images.
% Plot the boundary over the gray scale image
subplot(2, 2, 3);
plot(x, y, ‘y-‘, ‘LineWidth’, 3);
% For this blob, put a line between the points farthest away from each other.
line([x(index1), x(index2)], [y(index1), y(index2)], ‘Color’, ‘r’, ‘LineWidth’, 3);
plot(xMidPoint, yMidPoint, ‘r*’, ‘MarkerSize’, 15, ‘LineWidth’, 2);
% Plot perpendicular line. Make it green across the whole image but magenta inside the blob.
line([1, columns], [y1, y2], ‘Color’, ‘g’, ‘LineWidth’, 3);
line([cx(firstIndex), cx(lastIndex)], [cy(firstIndex), cy(lastIndex)], ‘Color’, ‘m’, ‘LineWidth’, 3);
% Plot the boundary over the binary image
subplot(2, 2, 4);
plot(x, y, ‘y-‘, ‘LineWidth’, 3);
% For this blob, put a line between the points farthest away from each other.
line([x(index1), x(index2)], [y(index1), y(index2)], ‘Color’, ‘r’, ‘LineWidth’, 3);
plot(xMidPoint, yMidPoint, ‘r*’, ‘MarkerSize’, 15, ‘LineWidth’, 2);
% Plot perpendicular line. Make it green across the whole image but magenta inside the blob.
line([1, columns], [y1, y2], ‘Color’, ‘g’, ‘LineWidth’, 3);
line([cx(firstIndex), cx(lastIndex)], [cy(firstIndex), cy(lastIndex)], ‘Color’, ‘m’, ‘LineWidth’, 3);
message = sprintf(‘The longest line is red.nPerpendicular to that, at the midpoint, is green.nMax distance for blob #%d = %.2fnPerpendicular distance at midpoint = %.2fnAverage perpendicular width = %.2f (approximatelynArea = %d’, …
blobIndex, maxDistance, perpendicularWidth, averageWidth, measurements(blobIndex).Area);
fprintf(‘%sn’, message);
uiwait(helpdlg(message));
end
hold off; Hi, i have problem in measuring the length and width the crack image.
i have follow the code but it only measure straight line (endpoint). I want the measurement by following the crack pattern. Please help me on this.
%load image
path=imgetfile();
originalImage1=imread(path);
imshow(originalImage1);
%image to grayscale
originalImage = rgb2gray(originalImage1);
figure
imshow(originalImage);
%treshold
thresholdValue = 100;
binaryImage = originalImage > thresholdValue;
binaryImage = imfill(binaryImage, ‘holes’);
hold on;
% maxYValue = ylim;
% line([thresholdValue, thresholdValue], maxYValue, ‘Color’, ‘r’);
% annotationText = sprintf(‘Thresholded at %d gray levels’, thresholdValue);
% text(double(thresholdValue + 5), double(0.5 * maxYValue(2)), annotationText, ‘FontSize’, 10, ‘Color’, [0 .5 0]);
% text(double(thresholdValue – 70), double(0.94 * maxYValue(2)), ‘Background’, ‘FontSize’, 10, ‘Color’, [0 0 .5]);
% text(double(thresholdValue + 50), double(0.94 * maxYValue(2)), ‘Foreground’, ‘FontSize’, 10, ‘Color’, [0 0 .5]);
figure
imshow(binaryImage);
% bw = bwareaopen(binaryImage,100,8);
bw= bwareaopen(binaryImage, round(0.1*numel(binaryImage)));
figure
imshow(bw)
g=bwmorph(bw,’clean’);
figure
imshow(g);
% %labeled image (on hold)
labeledImage = bwlabel(g,4);
figure
imshow(labeledImage, []);
%colored label image
coloredLabels = label2rgb (labeledImage, ‘hsv’, ‘k’, ‘shuffle’);
figure
imshow(coloredLabels);
axis image;
%blobmeasurement
blobMeasurements = regionprops(labeledImage, originalImage, ‘all’);
numberOfBlobs = size(blobMeasurements, 1);
figure
imshow(originalImage);
axis image; % Make sure image is not artificially stretched because of screen’s aspect ratio.
hold on;
boundaries = bwboundaries(binaryImage);
numberOfBoundaries = size(boundaries, 1);
for k = 1 : numberOfBoundaries
thisBoundary = boundaries{k};
plot(thisBoundary(:,2), thisBoundary(:,1), ‘g’, ‘LineWidth’, 2);
end
hold off;
% Measure the area
measurements = regionprops(labeledImage, ‘Area’);
boundaries = bwboundaries(binaryImage);
numberOfBoundaries = size(boundaries, 1);
for blobIndex = 1 : numberOfBoundaries
thisBoundary = boundaries{blobIndex};
x = thisBoundary(:, 2); % x = columns.
y = thisBoundary(:, 1); % y = rows.
% Find which two bounary points are farthest from each other.
maxDistance = -inf;
for k = 1 : length(x)
distances = sqrt( (x(k) – x) .^ 2 + (y(k) – y) .^ 2 );
[thisMaxDistance, indexOfMaxDistance] = max(distances);
if thisMaxDistance > maxDistance
maxDistance = thisMaxDistance;
index1 = k;
index2 = indexOfMaxDistance;
end
end
% Find the midpoint of the line.
xMidPoint = mean([x(index1), x(index2)]);
yMidPoint = mean([y(index1), y(index2)]);
longSlope = (y(index1) – y(index2)) / (x(index1) – x(index2))
perpendicularSlope = -1/longSlope
% Use point slope formula (y-ym) = slope * (x – xm) to get points
y1 = perpendicularSlope * (1 – xMidPoint) + yMidPoint;
y2 = perpendicularSlope * (columns – xMidPoint) + yMidPoint;
% Get the profile perpendicular to the midpoint so we can find out when if first enters and last leaves the object.
[cx,cy,c] = improfile(binaryImage,[1, columns], [y1, y2], 1000);
% Get rid of NAN’s that occur when the line’s endpoints go above or below the image.
c(isnan(c)) = 0;
firstIndex = find(c, 1, ‘first’);
lastIndex = find(c, 1, ‘last’);
% Compute the distance of that perpendicular width.
perpendicularWidth = sqrt( (cx(firstIndex) – cx(lastIndex)) .^ 2 + (cy(firstIndex) – cy(lastIndex)) .^ 2 );
% Get the average perpendicular width. This will approximately be the area divided by the longest length.
averageWidth = measurements(blobIndex).Area / maxDistance;
% Plot the boundaries, line, and midpoints over the two images.
% Plot the boundary over the gray scale image
subplot(2, 2, 3);
plot(x, y, ‘y-‘, ‘LineWidth’, 3);
% For this blob, put a line between the points farthest away from each other.
line([x(index1), x(index2)], [y(index1), y(index2)], ‘Color’, ‘r’, ‘LineWidth’, 3);
plot(xMidPoint, yMidPoint, ‘r*’, ‘MarkerSize’, 15, ‘LineWidth’, 2);
% Plot perpendicular line. Make it green across the whole image but magenta inside the blob.
line([1, columns], [y1, y2], ‘Color’, ‘g’, ‘LineWidth’, 3);
line([cx(firstIndex), cx(lastIndex)], [cy(firstIndex), cy(lastIndex)], ‘Color’, ‘m’, ‘LineWidth’, 3);
% Plot the boundary over the binary image
subplot(2, 2, 4);
plot(x, y, ‘y-‘, ‘LineWidth’, 3);
% For this blob, put a line between the points farthest away from each other.
line([x(index1), x(index2)], [y(index1), y(index2)], ‘Color’, ‘r’, ‘LineWidth’, 3);
plot(xMidPoint, yMidPoint, ‘r*’, ‘MarkerSize’, 15, ‘LineWidth’, 2);
% Plot perpendicular line. Make it green across the whole image but magenta inside the blob.
line([1, columns], [y1, y2], ‘Color’, ‘g’, ‘LineWidth’, 3);
line([cx(firstIndex), cx(lastIndex)], [cy(firstIndex), cy(lastIndex)], ‘Color’, ‘m’, ‘LineWidth’, 3);
message = sprintf(‘The longest line is red.nPerpendicular to that, at the midpoint, is green.nMax distance for blob #%d = %.2fnPerpendicular distance at midpoint = %.2fnAverage perpendicular width = %.2f (approximatelynArea = %d’, …
blobIndex, maxDistance, perpendicularWidth, averageWidth, measurements(blobIndex).Area);
fprintf(‘%sn’, message);
uiwait(helpdlg(message));
end
hold off; image processing, crack detection, length, width, regionprops, crack MATLAB Answers — New Questions
