Need some help regarding color detection and it's position

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i Venky
i Venky 2012-1-13
编辑： DGM 2023-2-14
I want to detect the color and it's position in an image. I don't get the output. I would be really happy if you could guide me.
Example: Take a red box in a white background at some position. I want to detect the red color and it's position (i.e. co-ordinates) in the image.
Thanks in advance.

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Chandra Kurniawan
Chandra Kurniawan 2012-1-14
Hi, i Venky
from my previous post, I've improved the code.
This picture below is test image :
Here the code :
Irgb = imread('multiplecolors.jpg');
Ihsv = rgb2hsv(Irgb);
low = 0;
high = 0.04;
h = (Ihsv(:,:,1) >= low) & (Ihsv(:,:,1) <= high);
s = (Ihsv(:,:,2) >= 0.9) & (Ihsv(:,:,2) <= 1);
v = (Ihsv(:,:,3) >= 0) & (Ihsv(:,:,3) <= 1);
mask = uint8(h & s & v);
mask = imclose(mask, strel('disk', 5));
mR = mask .* Irgb(:,:,1);
mG = mask .* Irgb(:,:,2);
mB = mask .* Irgb(:,:,3);
Icolor = cat(3, mR, mG, mB);
Igray = rgb2gray(Icolor);
Ibw = im2bw(Igray,graythresh(Igray));
Ilabel = bwlabel(Ibw);
stat = regionprops(Ilabel,'boundingbox','centroid');
imshow(Irgb); hold on;
for x = 1 : length(stat)
bb = stat(x).BoundingBox;
xc = stat(x).Centroid(1);
yc = stat(x).Centroid(2);
txt = sprintf('x : %.2f\ny : %.2f',xc,yc);
rectangle('position',bb,'edgecolor','b','linewidth',2);
plot(xc,yc,'bo');
text(xc,yc+30,txt,'color','y','fontweight','normal');
end
And the result shown below :
The pink colored object is not detected anymore.
It is so simple like I said. Just adjusting the values of hue, saturation, intensity.
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jyothi
jyothi 2014-5-14
hey thank u very much then what are the values for other different colors
Image Analyst
Image Analyst 2014-5-14
Extract them, then enter in a location and find out:
% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);

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更多回答（1 个）

Walter Roberson
Walter Roberson 2012-1-13
You have already been guided in your previous copy of this question.
In order to be guided further, you need to answer the question there as to how exactly you define each color.

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