如何更改对象跟踪中的颜色

Question

这是一个来自Arindam Bose的用于跟踪红色对象的Matlab示例代码。 我已经改变了这段代码来跟踪视频流中的对象。 最初是为了跟踪来自相机的红色物体。

http://www.mathworks.com/matlabcentral/fileexchange/28757-tracking-red-color-objects-using-matlab

不过我也想追踪与其他颜色，如绿色，黑色，白色等对象了。我正在研究代码，但无法真正看到在哪里更改此颜色信息。

也许是这行代码负责改变颜色？

diffFrame = imsubtract(rgbFrame(:,:,1), rgb2gray(rgbFrame)); % Get red component of the image 

或

我也改变了treshold，但没有成功：

redThresh = 0.15; % Threshold for red detection 

但不知道如何改变颜色oject绿色或其他颜色。

感谢您的任何建议。

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
% Program Name : Red Object Detection and Tracking 
% Author : Arindam Bose 
% Version : 1.05 
% Description : How to detect and track red objects in Live Video 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
%% Initialization 
redThresh = 0.15; % Threshold for red detection 

%vidDevice = imaq.VideoDevice('winvideo', 1, 'YUY2_640x480', ... % Acquire input video stream 
%'ROI', [1 1 640 480], ... 
%'ReturnedColorSpace', 'rgb'); 

vidInfo = VideoReader('MyVideo.avi'); 
videoResult = VideoWriter('C:\MyProject\Y_Videos\ResultVideo.avi'); % Finales Video mit Koordinaten der roten Blobs 
open(videoResult); % Öffne finales Video 

% vidInfo = readframe(video); % Acquire input video property 

hblob = vision.BlobAnalysis('AreaOutputPort', false, ... % Set blob analysis handling 
'CentroidOutputPort', true, ... 
'BoundingBoxOutputPort', true', ... 
'MinimumBlobArea', 10, ... 
'MaximumBlobArea', 950, ... 
'MaximumCount', 30); 
hshapeinsRedBox = vision.ShapeInserter('BorderColor', 'Custom', ... % Set Red box handling 
'CustomBorderColor', [255 255 255], ... 
'Fill', true, ... 
'FillColor', 'Custom', ... 
'CustomFillColor', [0 0 0], ... 
'Opacity', 0.3); 
htextins = vision.TextInserter('Text', 'Red Objects: %2d', ... % Set text for number of blobs 
'Location', [7 2], ... 
'Color', [255 255 255], ... // red color 
'FontSize', 14); 
htextinsCent = vision.TextInserter('Text', '+ X:%4d, Y:%4d', ... % set text for centroid 
'LocationSource', 'Input port', ... 
'Color', [255 255 255], ... // white color 
'FontSize', 14); 

hVideoIn = vision.VideoPlayer('Name', 'Final Video', ... % Output video player 
'Position', [100 100 610 500]); 
nFrame = 0; % Frame number initialization 
%% Processing Loop 
while(nFrame < 500) 
rgbFrame = readFrame(vidInfo); 
%rgbFrame = step(vidDevice); % Acquire single frame 
%rgbFrame = flip(rgbFrame,2); % obtain the mirror image for displaying 
diffFrame = imsubtract(rgbFrame(:,:,1), rgb2gray(rgbFrame)); % Get red component of the image 
diffFrame = medfilt2(diffFrame, [3 3]); % Filter out the noise by using median filter 
binFrame = im2bw(diffFrame, redThresh); % Convert the image into binary image with the red objects as white 
[centroid, bbox] = step(hblob, binFrame); % Get the centroids and bounding boxes of the blobs 
centroid = uint16(centroid); % Convert the centroids into Integer for further steps 
rgbFrame(1:20,1:165,:) = 100; % put a black region on the output stream 
vidIn = step(hshapeinsRedBox, rgbFrame, bbox); % Instert the red box 

for object = 1:1:length(bbox(:,1)) % Write the corresponding centroids 
centX = centroid(object,1); 
centY = centroid(object,2); 
vidIn = step(htextinsCent, vidIn, [centX centY], [centX-6 centY-9]); 
end 
vidIn = step(htextins, vidIn, uint8(length(bbox(:,1)))); % Count the number of blobs 
step(hVideoIn, vidIn); % Output video stream 

writeVideo(videoResult,vidIn) 

nFrame = nFrame+1; 
end 

%% Clearing Memory 
release(hVideoIn); % Release all memory and buffer used 
%% release(vidDevice); 
%%clear all; 
close(videoResult); 

clc; 

Answer 1

你的猜测是正确的。彩色图像是n x m x 3矩阵，所以img(:,:,1)是红色通道，img(:,:,2)是绿色的，而img(:,:,3)是蓝色的。