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Shubham Sharma on 25 Jul 2024 at 10:49
Edited: Walter Roberson on 25 Jul 2024 at 16:37
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% Define area threshold (e.g., 100 pixels)
areaThreshold = 500; % Set your desired threshold value here
% Read the TIFF image
image = imread('quartz1.tif');
% Convert to grayscale if not already
if size(image, 3) == 3
grayImage = rgb2gray(image);
else
grayImage = image;
end
% Apply Gaussian blur
blurredImage = imgaussfilt(grayImage, 2);
% Enhance contrast
enhancedImage = imadjust(blurredImage);
% Apply sharpening
sharpenedImage = imsharpen(enhancedImage);
% Detect edges
edges = edge(sharpenedImage, 'Canny');
% Find contours
contours = bwconncomp(edges);
% Calculate properties for each grain
stats = regionprops(contours, 'Area', 'Perimeter', 'MajorAxisLength', 'MinorAxisLength', 'Orientation', 'BoundingBox', 'PixelIdxList', 'Centroid');
% Process each grain
for i = 1:length(stats)
if stats(i).Area > areaThreshold
% Get the bounding box for each grain
bb = stats(i).BoundingBox;
grainRegion = imcrop(grayImage, bb);
% Create a new image to draw axes
grainImageWithAxes = cat(3, grainRegion, grainRegion, grainRegion);
% Get the ellipse properties
orientation = stats(i).Orientation;
majorAxisLength = stats(i).MajorAxisLength;
minorAxisLength = stats(i).MinorAxisLength;
perimeter = stats(i).Perimeter; % Perimeter value
centerX = stats(i).Centroid(1) - bb(1);
centerY = stats(i).Centroid(2) - bb(2);
% Compute the endpoints of the major and minor axes
majorAxisEnd1 = [centerX + majorAxisLength / 2 * cosd(orientation), centerY - majorAxisLength / 2 * sind(orientation)];
majorAxisEnd2 = [centerX - majorAxisLength / 2 * cosd(orientation), centerY + majorAxisLength / 2 * sind(orientation)];
minorAxisEnd1 = [centerX + minorAxisLength / 2 * cosd(orientation + 90), centerY - minorAxisLength / 2 * sind(orientation + 90)];
minorAxisEnd2 = [centerX - minorAxisLength / 2 * cosd(orientation + 90), centerY + minorAxisLength / 2 * sind(orientation + 90)];
% Ensure endpoints are within bounds of the image
majorAxisEnd1 = max(min(majorAxisEnd1, size(grainRegion, 2) - 1), 1);
majorAxisEnd2 = max(min(majorAxisEnd2, size(grainRegion, 2) - 1), 1);
minorAxisEnd1 = max(min(minorAxisEnd1, size(grainRegion, 2) - 1), 1);
minorAxisEnd2 = max(min(minorAxisEnd2, size(grainRegion, 2) - 1), 1);
% Draw the axes
grainImageWithAxes = insertShape(grainImageWithAxes, 'Line', [majorAxisEnd1, majorAxisEnd2], 'Color', 'red', 'LineWidth', 3);
grainImageWithAxes = insertShape(grainImageWithAxes, 'Line', [minorAxisEnd1, minorAxisEnd2], 'Color', 'blue', 'LineWidth', 3);
% Draw contour (perimeter)
contour = bwboundaries(contours.PixelIdxList{i});
contourVertices = contour{1} - [bb(1), bb(2)];
% Convert contourVertices to a cell array with one matrix
contourVerticesCell = {contourVertices};
% Draw the contour
grainImageWithAxes = insertShape(grainImageWithAxes, 'Polygon', 'Vertices', {contourVertices}, 'Color', 'green', 'LineWidth', 2);
% Add text annotations with larger font size
grainImageWithAxes = insertText(grainImageWithAxes, [10 10], sprintf('Major Axis: %.2f', majorAxisLength), 'FontSize', 12, 'TextColor', 'red', 'BoxColor', 'black');
grainImageWithAxes = insertText(grainImageWithAxes, [10 30], sprintf('Minor Axis: %.2f', minorAxisLength), 'FontSize', 12, 'TextColor', 'blue', 'BoxColor', 'black');
grainImageWithAxes = insertText(grainImageWithAxes, [10 50], sprintf('Perimeter: %.2f', perimeter), 'FontSize', 12, 'TextColor', 'green', 'BoxColor', 'black');
% Save the image with axes using PNG format
filename = sprintf('grain_%d_axes.png', i);
imwrite(grainImageWithAxes, filename, 'PNG');
% Display the image with axes
figure;
imshow(grainImageWithAxes);
title(sprintf('Sand Grain %d', i));
end
end
the error i am getting is
Error using insertShape
Expected POSITION to be one of these types:
cell
Error in insertShape>checkPosition (line 332)
validateattributes(position,{'cell'}, {'nonempty', 'vector'}, ...
Error in insertShape>validateAndParseInputs (line 256)
checkPosition(position, shape1);
Error in insertShape (line 129)
validateAndParseInputs(I, shape, position, varargin{:});
Error in untitled8 (line 74)
grainImageWithAxes = insertShape(grainImageWithAxes, 'Polygon', 'Vertices', {contourVertices}, 'Color', 'green', 'LineWidth', 2);
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Answers (1)
Karan Singh on 25 Jul 2024 at 11:08
Open in MATLAB Online
- tiffbucket.zip
@Shubham Sharma
It looks like there's an issue with the way the vertices are being passed to the insertShape function. The Vertices parameter expects a cell array. The conversion to a cell array is not being done correctly.
Here Is the corrected code.
% Define area threshold (e.g., 100 pixels)
areaThreshold = 500; % Set your desired threshold value here
% Read the TIFF image
unzip tiffbucket.zip
image = imread('indexedblobs.tiff');
% Convert to grayscale if not already
if size(image, 3) == 3
grayImage = rgb2gray(image);
else
grayImage = image;
end
% Apply Gaussian blur
blurredImage = imgaussfilt(grayImage, 2);
% Enhance contrast
enhancedImage = imadjust(blurredImage);
% Apply sharpening
sharpenedImage = imsharpen(enhancedImage);
% Detect edges
edges = edge(sharpenedImage, 'Canny');
% Find contours
contours = bwconncomp(edges);
% Calculate properties for each grain
stats = regionprops(contours, 'Area', 'Perimeter', 'MajorAxisLength', 'MinorAxisLength', 'Orientation', 'BoundingBox', 'PixelIdxList', 'Centroid');
% Process each grain
for i = 1:length(stats)
if stats(i).Area > areaThreshold
% Get the bounding box for each grain
bb = stats(i).BoundingBox;
grainRegion = imcrop(grayImage, bb);
% Create a new image to draw axes
grainImageWithAxes = cat(3, grainRegion, grainRegion, grainRegion);
% Get the ellipse properties
orientation = stats(i).Orientation;
majorAxisLength = stats(i).MajorAxisLength;
minorAxisLength = stats(i).MinorAxisLength;
perimeter = stats(i).Perimeter; % Perimeter value
centerX = stats(i).Centroid(1) - bb(1);
centerY = stats(i).Centroid(2) - bb(2);
% Compute the endpoints of the major and minor axes
majorAxisEnd1 = [centerX + majorAxisLength / 2 * cosd(orientation), centerY - majorAxisLength / 2 * sind(orientation)];
majorAxisEnd2 = [centerX - majorAxisLength / 2 * cosd(orientation), centerY + majorAxisLength / 2 * sind(orientation)];
minorAxisEnd1 = [centerX + minorAxisLength / 2 * cosd(orientation + 90), centerY - minorAxisLength / 2 * sind(orientation + 90)];
minorAxisEnd2 = [centerX - minorAxisLength / 2 * cosd(orientation + 90), centerY + minorAxisLength / 2 * sind(orientation + 90)];
% Ensure endpoints are within bounds of the image
majorAxisEnd1 = max(min(majorAxisEnd1, size(grainRegion, 2) - 1), 1);
majorAxisEnd2 = max(min(majorAxisEnd2, size(grainRegion, 2) - 1), 1);
minorAxisEnd1 = max(min(minorAxisEnd1, size(grainRegion, 2) - 1), 1);
minorAxisEnd2 = max(min(minorAxisEnd2, size(grainRegion, 2) - 1), 1);
% Draw the axes
grainImageWithAxes = insertShape(grainImageWithAxes, 'Line', [majorAxisEnd1, majorAxisEnd2], 'Color', 'red', 'LineWidth', 3);
grainImageWithAxes = insertShape(grainImageWithAxes, 'Line', [minorAxisEnd1, minorAxisEnd2], 'Color', 'blue', 'LineWidth', 3);
% Draw contour (perimeter)
contour = bwboundaries(contours.PixelIdxList{i});
contourVertices = contour{1} - [bb(1), bb(2)];
% Convert contourVertices to a cell array with one matrix
contourVerticesCell = {contourVertices};
% Draw the contour
grainImageWithAxes = insertShape(grainImageWithAxes, 'Polygon', contourVerticesCell, 'Color', 'green', 'LineWidth', 2);
% Add text annotations with larger font size
grainImageWithAxes = insertText(grainImageWithAxes, [10 10], sprintf('Major Axis: %.2f', majorAxisLength), 'FontSize', 12, 'TextColor', 'red', 'BoxColor', 'black');
grainImageWithAxes = insertText(grainImageWithAxes, [10 30], sprintf('Minor Axis: %.2f', minorAxisLength), 'FontSize', 12, 'TextColor', 'blue', 'BoxColor', 'black');
grainImageWithAxes = insertText(grainImageWithAxes, [10 50], sprintf('Perimeter: %.2f', perimeter), 'FontSize', 12, 'TextColor', 'green', 'BoxColor', 'black');
% Save the image with axes using PNG format
filename = sprintf('grain_%d_axes.png', i);
imwrite(grainImageWithAxes, filename, 'PNG');
% Display the image with axes
figure;
imshow(grainImageWithAxes);
title(sprintf('Sand Grain %d', i));
end
end
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