Hello, I want to crop an image according to rectengular shape created by laser light.I would read a serial number from this cropped image.
MATLAB: I want to crop an image accoording to shape created by laser (imcrop)
auto shapeImage Processing Toolboximcroprectengularred line
Related Solutions
Did you try:
croppedImage = imcrop(fullImage, cropBox); % You specify cropping locations.
meanGL = mean2(croppedImage);sdGL = mean2(croppedImage);See this demo that uses imfreehand, in case you're interested in that instead.
% Demo to have the user freehand draw an irregular shape over a gray scale image.
% Then it creates new images:
% (1) where the drawn region is all white inside the region and untouched outside the region,
% (2) where the drawn region is all black inside the region and untouched outside the region,
% (3) where the drawn region is untouched inside the region and all black outside the region.
% It also (4) calculates the mean intensity value and standard deviation of the image within that shape,
% (5) calculates the perimeter, centroid, and center of mass (weighted centroid), and
% (6) crops the drawn region to a new, smaller separate image.
% Change the current folder to the folder of this m-file.
if(~isdeployed) cd(fileparts(which(mfilename)));endclc; % Clear command window.
clear; % Delete all variables.
close all; % Close all figure windows except those created by imtool.
imtool close all; % Close all figure windows created by imtool.
workspace; % Make sure the workspace panel is showing.
fontSize = 16;% Read in a standard MATLAB gray scale demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');baseFileName = 'cameraman.tif';% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);% Check if file exists.
if ~exist(fullFileName, 'file') % File doesn't exist -- didn't find it there. Check the search path for it.
fullFileName = baseFileName; % No path this time.
if ~exist(fullFileName, 'file') % Still didn't find it. Alert user.
errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName); uiwait(warndlg(errorMessage)); return; endendgrayImage = imread(fullFileName);imshow(grayImage, []);axis on;title('Original Grayscale Image', 'FontSize', fontSize);set(gcf, 'Position', get(0,'Screensize')); % Maximize figure.
message = sprintf('Left click and hold to begin drawing.\nSimply lift the mouse button to finish');uiwait(msgbox(message));hFH = imfreehand();% Create a binary image ("mask") from the ROI object.
binaryImage = hFH.createMask();xy = hFH.getPosition;% Now make it smaller so we can show more images.
subplot(2, 3, 1);imshow(grayImage, []);axis on;drawnow;title('Original Grayscale Image', 'FontSize', fontSize);% Display the freehand mask.
subplot(2, 3, 2);imshow(binaryImage);axis on;title('Binary mask of the region', 'FontSize', fontSize);% Label the binary image and computer the centroid and center of mass.
labeledImage = bwlabel(binaryImage);measurements = regionprops(binaryImage, grayImage, ... 'area', 'Centroid', 'WeightedCentroid', 'Perimeter');area = measurements.Areacentroid = measurements.CentroidcenterOfMass = measurements.WeightedCentroidperimeter = measurements.Perimeter% Calculate the area, in pixels, that they drew.
numberOfPixels1 = sum(binaryImage(:))% Another way to calculate it that takes fractional pixels into account.
numberOfPixels2 = bwarea(binaryImage)% Get coordinates of the boundary of the freehand drawn region.
structBoundaries = bwboundaries(binaryImage);xy=structBoundaries{1}; % Get n by 2 array of x,y coordinates.
x = xy(:, 2); % Columns.
y = xy(:, 1); % Rows.
subplot(2, 3, 1); % Plot over original image.
hold on; % Don't blow away the image.
plot(x, y, 'LineWidth', 2);drawnow; % Force it to draw immediately.
% Burn line into image by setting it to 255 wherever the mask is true.
burnedImage = grayImage;burnedImage(binaryImage) = 255;% Display the image with the mask "burned in."
subplot(2, 3, 3);imshow(burnedImage);axis on;caption = sprintf('New image with\nmask burned into image');title(caption, 'FontSize', fontSize);% Mask the image and display it.
% Will keep only the part of the image that's inside the mask, zero outside mask.
blackMaskedImage = grayImage;blackMaskedImage(~binaryImage) = 0;subplot(2, 3, 4);imshow(blackMaskedImage);axis on;title('Masked Outside Region', 'FontSize', fontSize);% Calculate the mean
meanGL = mean(blackMaskedImage(binaryImage));sdGL = std(double(blackMaskedImage(binaryImage)));% Put up crosses at the centriod and center of mass
hold on;plot(centroid(1), centroid(2), 'r+', 'MarkerSize', 30, 'LineWidth', 2);plot(centerOfMass(1), centerOfMass(2), 'g+', 'MarkerSize', 20, 'LineWidth', 2);% Now do the same but blacken inside the region.
insideMasked = grayImage;insideMasked(binaryImage) = 0;subplot(2, 3, 5);imshow(insideMasked);axis on;title('Masked Inside Region', 'FontSize', fontSize);% Now crop the image.
leftColumn = min(x);rightColumn = max(x);topLine = min(y);bottomLine = max(y);width = rightColumn - leftColumn + 1;height = bottomLine - topLine + 1;croppedImage = imcrop(blackMaskedImage, [leftColumn, topLine, width, height]);% Display cropped image.
subplot(2, 3, 6);imshow(croppedImage);axis on;title('Cropped Image', 'FontSize', fontSize);% Put up crosses at the centriod and center of masshold on;plot(centroid(1)-leftColumn, centroid(2)-topLine, 'r+', 'MarkerSize', 30, 'LineWidth', 2);plot(centerOfMass(1)-leftColumn, centerOfMass(2)-topLine, 'g+', 'MarkerSize', 20, 'LineWidth', 2);% Report results.
message = sprintf('Mean value within drawn area = %.3f\nStandard deviation within drawn area = %.3f\nNumber of pixels = %d\nArea in pixels = %.2f\nperimeter = %.2f\nCentroid at (x,y) = (%.1f, %.1f)\nCenter of Mass at (x,y) = (%.1f, %.1f)\nRed crosshairs at centroid.\nGreen crosshairs at center of mass.', ...meanGL, sdGL, numberOfPixels1, numberOfPixels2, perimeter, ...centroid(1), centroid(2), centerOfMass(1), centerOfMass(2));msgbox(message);
Best Answer