MATLAB: Save snapshot image in a variable within a loop!!

Image Acquisition Toolboxvideo

please need help in this why the data(i) variable in while loop give me an error here I want to take a picture after each 5 second and I need it continuous so I used while(1) …

vid = videoinput('winvideo',1);
set(vid, 'FramesPerTrigger', Inf);
set(vid, 'ReturnedColorspace', 'rgb');
i = 0; 
while(1)
    data(i) = getsnapshot(vid);
    imshow(data(i));
    i=i+1;
    pause(5);
end

Best Answer

Get rid of the (i) and have just data, or better yet, a more descriptive filename:

for f = 1 : 1000 % view and save 1000 frames then quit.
    thisFrame = getsnapshot(vid);
    imshow(thisFrame);
    drawnow;
    baseFileName = sprintf('Frame %3.3d.png', f);
    fullFileName = fullfile(folder, baseFileName);
    imwrite(thisFrame, fullFileName);
end

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MATLAB: Image acquisition, frame rgb2gray conversion

The rgb2gray function only works on a single image, but you are sending it an array of images.

What is the format that you ultimately need the data in? It looks like your camera is returning YUV data, but you're converting it to RGB data and then attempting to convert it to monochrome data. If you're converting to RGB data just to display one frame in the imshow command, I would leave the data as YUV, i.e. don't set the ReturnedColorSpaceProperty, and convert the frame that you want to display to RGB:

   imshow( ycbcr2rgb( frames(:,:,:,1))).

The first band of the YUV data is the luminance band, so you should be able to use that directly as your monochrome data:

   Sgray = frames(:,:,1,:);

The command to write a frame as jpeg (as well as many other formats) is imwrite.

MATLAB: Images not performing all functions inside for loop!!

You are savin gonly the last image features, you need to save all the image features into a cell/matrix.

Dir = 'C:\Users\Administrator\Desktop\Tinna\PROJECT\soil_jpg\DataSet';
images = dir(fullfile(Dir,'*.jpg'));
F1 = cell(length(images),1) ;
F2 = cell(length(images),1) ;
F3 = cell(length(images),1) ;
F4 = cell(length(images),1) ;
F5 = cell(length(images),1) ;
F6 = cell(length(images),1) ;
for m = 1 : length(images)
    Img = imread(fullfile(Dir,images(m).name));
    Img = imadjust(Img,stretchlim(Img));
    Img = imresize(Img,[256,256]);
    hsvHist = hsvHistogram(Img);
    autoCorrelogram = colorAutoCorrelogram(Img);
    color_moments = colorMoments(Img);
    % for gabor filters we need gray scale image
    img = double(rgb2gray(Img))/255;
    [meanAmplitude, msEnergy] = gaborWavelet(img, 4, 6); % 4 = number of scales, 6 = number of orientations
    wavelet_moments = waveletTransform(Img);
    Feature_Vector = [hsvHist autoCorrelogram color_moments meanAmplitude msEnergy wavelet_moments];
    whos Feature_Vector
    F1{m} = mean2(hsvHist(:));
    F2{m} = mean2(autoCorrelogram(:));
    F3{m} = mean2(color_moments(:));
    F4{m} = mean2(meanAmplitude(:));
    F5{m} = mean2(msEnergy(:));
    F6{m} = mean2(wavelet_moments(:));
end
xlswrite('testdata.xlsx',[F1 F2 F3 F4 F5 F6]);

Best Answer

Related Solutions

MATLAB: Image acquisition, frame rgb2gray conversion

MATLAB: Images not performing all functions inside for loop!!

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