May i know how to find for numYellowPixel in this code

Question

Iszuzuldin amirull bin mohd janudin 2021-6-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/852320-may-i-know-how-to-find-for-numyellowpixel-in-this-code

编辑： Image Analyst 2021-6-11

clc
clear
clear all
images= []
webcamlist()
cam= webcam(1)
preview(cam)
pause(2);
images= snapshot(cam)
imshow(images)
r_channel= images(:,:,1);
g_channel= images(:,:,2);
b_channel= images(:,:,3);
images(:,:,1) =0;
images(:,:,3) = 0;
image(images);
mask= g_channel > 100, b_channel > 800, r_channel < 800, b_channel < 0, r_channel < 0;
numBlackPixels = sum(~mask(:))
 gr_ratio = double(g_channel)./double(r_channel);
 gb_ratio = double(g_channel)./double(b_channel);
 rb_ratio = double(r_channel)./double(b_channel);
 
% gr_ratio(isnan(g_ratio))=0;
% grayImage = rgb2gray(image);
% binaryImage = grayImage > 20;
% binaryImage = bwareaopen(binaryImage, 50);
% binaryImage = imfill(binaryImage, 'holes');
% grayImage(~binaryImage) = 0;
falseMatrix= zeros(7,7);
targetMatrix= ones(7,7);
checkMatrix= ones(7,7);
fprintf('mask has %d black pixels.\n', numBlackPixels);
if targetMatrix == checkMatrix
%     cam = camStop;
    return
end

2 个评论
显示无隐藏无

Jan 2021-6-9

在 MATLAB Online 中打开

It is not getting clear to me, what you are asking for.

What is the purpose of this line:

mask= g_channel > 100, b_channel > 800, r_channel < 800, b_channel < 0, r_channel < 0;

Only the first comparison matters, the rest is ignored.

Sulaymon Eshkabilov 2021-6-9

Note that "yellow" color pixel is the composition of three layers, viz. Red, Green, Blue. From these three layers in combination, you'd need to create a mask that gives a "Yellow" pixel.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Image Analyst 2021-6-10

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/852320-may-i-know-how-to-find-for-numyellowpixel-in-this-code#answer_721355

Use the ColorThresholder app on the Apps tab of the tool ribbon to create a mask. Then export the function and call it whenever you need to find the yellow mask.

2 个评论
显示无隐藏无

Iszuzuldin amirull bin mohd janudin 2021-6-11

One more questions, how to get pixels of each mango?

Image Analyst 2021-6-11

编辑：Image Analyst 2021-6-11

在 MATLAB Online 中打开

Exactly what does "get" mean to you. Please be very specific, like locations, colors, both, whatever. Basically use find() and imsplit().

[r,g,b] = imsplit(rgbImage);
[rows, columns] = find(mask); % the BW from the Color Threshold app.
redPixels = r(mask);
greenPixels = g(mask);
bluePixels = b(mask);