MATLAB: Explain 4-D unit8

Image Processing Toolboxvideovideo processing

when i read the video ex- vid = read(obj); then in vid we get the 4-D uint8..then 4d means(h,w,b,f) is or not..

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Height, Width, Color Plane, Frame Number, where Color Plane is in the order Red, Green, Blue

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MATLAB: Enter values into a FIFO array

I think you are trying to save last five frames in a buffer, but a for loop is not required for that purpose

frameBuffer=zeros (height, width, numChannels, framesPerSymbol);
framesInBuffer = 0;

While loop

while hasFrame(videoObject)
    frame = double(readFrame(videoObject));

I made a change here

    frameBuffer = shiftBuffer(frameBuffer,frame);  
    framesInBuffer = framesInBuffer + 1;

    if framesInBuffer > framesPerSymbol
        framesInBuffer = framesPerSymbol;
        bypassEncoding = false;
    else
        bypassEncoding = true;
    end
    if ~bypassEncoding
        if canWeEncode(frameBuffer,alpha,threshold)    
            encodedBuffer = steganographicEncoding(frameBuffer,width,height,codeRows,codeCols,alpha,sigma);
            writeBufferToFinalVideo(encodedBuffer,100);
        else                                        
            writeFrameToFinalVideo(squeeze(frameBuffer(:,:,:,1)));
        end
    end
end

and a change here

function frameBuffer = shiftBuffer (frameBuffer,frame)
frameBuffer = circshift(frameBuffer,1,4); 
frameBuffer(:,:,:,1) = frame;
end

MATLAB: Insert elements into a 4D array

There are 2 mistakes in the above implementation:

Accessing a frame of frameBuffer as frameBuffer(i) instead of frameBuffer(:,:,:,i)
The function shiftBuffer changes the values of frameBuffer locally in the function and in the main code the frameBuffer isn't changed.

I suggest you to make the following changes.

Change the function shiftBuffer as follows:

function frameBuffer = shiftBuffer(frameBuffer,frame,framesInBuffer)
frameBuffer(:,:,:,,framesInBuffer) = frame;
end

and the following lines in your code

frame = readFrame(videoObject);    
shiftBuffer(frameBuffer,frame);       % <--------- THIS IS THE PART
% We update the framesInBuffer counter

framesInBuffer = framesInBuffer + 1;

frame = readFrame(videoObject);
% We update the framesInBuffer counter
framesInBuffer = framesInBuffer + 1;
frameBuffer = shiftBuffer(frameBuffer,frame,framesInBuffer);

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Related Solutions

MATLAB: Enter values into a FIFO array

MATLAB: Insert elements into a 4D array

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