how i can find the blue object in the image by using the arrows in the picture ?

the arrows has yellow dots ? how i can find the loctaion of these objects . I used the regionprobs to differentiate the objects . however, the intensoty level of yellow dots and its location i coudent reach it .

Answer 1

[Image Analyst]

You can find the blue region without the arrow, just find where the pixels have a blue signal but no red or green signal. If you need to follow the arrows, then you'll need to give some rules because the blue blob could be virtually anywhere, completely independent of the arrows. Do you need to find all blobs that could be intersected by a projection of the line from the last two arrows? What if it might point both to a blue blob and an earlier white or red blob? You'd have to find out which one is the blue blob. But if you're doing that, then why bother following the arrow anyway? Might there be lots of blue blobs, some of which might be intersected and some not intersected. I think you need to better define the problem before it could be answered. Otherwise, I could find the arrows but then also find the blue blob and essentially just ignore the arrows.

[Mohammed Basheer]

hi , the task is to use arrows to find object in any images have arrows . the satrt point is the red arrow . after that you have to find neaerst arrow and the direction of arrow by using the centroid and yellow position in each opbject . however, the challenge is how i can find yellow position in each object.

close all;

clear all;

%% Reading image

im = imread('Treasure_easy.jpg'); % change name to process other images

imshow(im);

pause;

%% Binarisation

bin_threshold = 0.1; % parameter to vary

bin_im = im2bw(im, bin_threshold);

imshow(bin_im);

pause;

%% Extracting connected components

con_com = bwlabel(bin_im);

imshow(label2rgb(con_com));

pause;

%% Computing objects properties

props = regionprops(con_com);

%% Drawing bounding boxes

n_objects = numel(props);

imshow(im);

hold on;

for object_id = 1 : n_objects

rectangle('Position', props(object_id).BoundingBox, 'EdgeColor', 'b');

end

hold off;

pause;

%% Arrow/non-arrow determination

% You should develop a function arrow_finder, which returns the IDs of the arror objects.

% IDs are from the connected component analysis order. You may use any parameters for your function.

blobMeasurements = regionprops(con_com,'all');

numberOfBlobs = size(blobMeasurements, 1);

allBlobAreas = [blobMeasurements.Area];

allowableAreaIndexes = allBlobAreas < 2000;

keeperIndexes = find(allowableAreaIndexes);

keeperBlobsImage = ismember(con_com, keeperIndexes);

labeledDimeImage = bwlabel(keeperBlobsImage, 8)

imshow(labeledDimeImage, []);

%% Finding red arrow

n_arrows = numel(keeperIndexes);

start_arrow_id = 0;

% check each arrow until find the red one

for arrow_num = 1 : n_arrows

object_id = keeperIndexes(arrow_num); % determine the arrow id

% extract colour of the centroid point of the current arrow

centroid_colour = im(round(props(object_id).Centroid(2)), round(props(object_id).Centroid(1)), :);

if centroid_colour(:, :, 1) > 240 && centroid_colour(:, :, 2) < 10 && centroid_colour(:, :, 3) < 10

% the centroid point is red, memorise its id and break the loop

start_arrow_id = object_id;

break;

end

after that i need to comblete the programm to find the shortest path by using arrows to reach the blue object

[Image Analyst]

You're essentially finding all blobs then examining them to find the red one. You can just skip that and find the red one directly if you want. But then you still have to find all the other blobs, white and blue. You could just find the blue one directly using color segmentation like you did with the red one. So then you'd just ignore the white ones. If you're not allowed to ignore the white ones, then you'll have to identify the white arrows

whiteArrows = sum(rgbImage, 3) > 3*128;

and then you'd have to identify which direction it points to. You could call regionprops() to get the centroids and bounding boxes of all the white arrows, then do a segmentation for the yellow spots and find out which quadrant of the bounding box the yellow spot lies in. So now you have a list of arrows with what direction they point to. But again, to find the blue blob you still need to check that it's blue, and if you do that, there was no reason to inspect all the arrows.

[Mohammed Basheer]

I need your help for how i can do a segmentation for the yellow spots and find out which quadrant of the bounding box the yellow spot lies ? how i can find the direction of arrow becuase you know i have to find the shortest way to find the blue object . i use the programm below i didnt get the yellow points in object . i need the position of yellow pixels in each opbject that it will help me with the centoids of each object to identify the direction of arrows .

im=imread('Treasure_easy.jpg');

red_channel = im(:, :, 1);

green_channel = im(:, :, 2);

blue_channel = im(:, :, 3);

% label pixels of yellow colour

yellow_map = green_channel > 150 & red_channel > 150 & blue_channel < 50;

% extract pixels indexes

[i_yellow, j_yellow] = find(yellow_map > 0);

[Image Analyst]

OK Mohammed, I'll give you a little more but I think you want the code to be yours rather than mine so we need to leave enough for you to do so that you feel at least a little bit of ownership of it, especially since it looks very much like a homework assignment.

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;

folder = pwd;
baseFileName = 'Treasure_easy.jpg';
% baseFileName = 'IMG_Segment_Success.JPEG';
fullFileName = fullfile(folder, baseFileName);
rgbImage = imread(fullFileName);
% Display the original image.
subplot(2, 3, 1);
imshow(rgbImage, []);
axis('on', 'image');
caption = sprintf('Original Color Image\n"%s"', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0.05 1 0.95]);
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by Image Analyst', 'NumberTitle', 'Off')

% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);

% Get the red mask.
redMask = redChannel > 128 & greenChannel < 128 & blueChannel < 128;
subplot(2, 3, 4);
imshow(redMask);
grid on;
title('Red Mask', 'FontSize', fontSize, 'Interpreter', 'None');

% Get the white mask.
whiteMask = redChannel > 128 & greenChannel > 128 & blueChannel > 128;
% Display the image.
subplot(2, 3, 2);
imshow(whiteMask, []);
axis('on', 'image');
caption = sprintf('White Mask of \n"%s"', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.

% Get the yellow mask.
yellowMask = redChannel > 128 & greenChannel > 128 & blueChannel < 128;
subplot(2, 3, 3);
imshow(yellowMask);
grid on;
title('Yellow Mask', 'FontSize', fontSize, 'Interpreter', 'None');

% Get the blue mask.
blueMask = redChannel < 128 & greenChannel < 128 & blueChannel > 128;
subplot(2, 3, 5);
imshow(blueMask);
grid on;
title('Blue Mask', 'FontSize', fontSize, 'Interpreter', 'None');

% Get the bounding boxes and centroid of the red arrows
propsR = regionprops(redMask, 'BoundingBox', 'Centroid');
% Get the bounding boxes and centroid of the white arrows
propsW = regionprops(whiteMask, 'BoundingBox', 'Centroid');
% Get the bounding boxes and centroid of the yellow spots
propsY = regionprops(yellowMask, 'BoundingBox', 'Centroid');

% Figure out what direction each white arrow is pointing.
subplot(2, 3, 3);
hold on;
for k = 1 : length(propsW)
	thisBB = propsW(k).BoundingBox;
	rectangle('Position', thisBB, 'EdgeColor', 'y', 'LineWidth', 1);
	thisYellowCentroidX = propsY(k).Centroid(1);
	thisYellowCentroidY = propsY(k).Centroid(2);
	x1 = thisBB(1);
	x2 = x1 + thisBB(3);
	y1 = thisBB(2);
	y2 = y1 + thisBB(4);
	% Now find out where the yellow centroid lies within the bounding box.
end

See what you can do with this.

[Mohammed Basheer]

I need to create a path from red arrow and reach to last arrow which is direct to blue object by checking the closest arrow and set it to the path

regarding to program you can put at your own efforsts

thank you so much