Post-Processing Video for Thermal Analysis

Hello all,

I have a question with regards to post-processing a video of thermal values. I have two questions:

1) I converted a video from WMV to AVI to grayscale. How do I correlate the grayscale values to temperature values? I have a scale from the program I am using to correlate it, but I assume the video doesn't have these values.

2) I have code (borrowed from here: http://www.mathworks.com/help/images/examples/detecting-cars-in-a-video-of-traffic.html) that finds the maximum temperature area. How can I tell MATLAB to grab values from this area for each frame and put them in an array?

My code, thus far, is as follows:

file = 'Test.avi';

reader = VideoReader(file); get(reader); implay(file);

nframes = reader.NumberOfFrames; %Use 'CurrentTime' in future releases

background = 6; darkCar = rgb2gray(read(reader,nframes*.5)); noDarkCar = imextendedmax(darkCar, background); imshow(darkCar) figure, imshow(noDarkCar)

sedisk = strel('disk',2); noSmallStructures = imopen(noDarkCar, sedisk); imshow(noSmallStructures)

%nframes = reader.NumberOfFrames; I = read(reader, 1); taggedCars = zeros([size(I,1) size(I,2) 3 nframes], class(I));

for k = 1 : nframes singleFrame = read(reader, k);

    % Convert to grayscale to do morphological processing.
    I = rgb2gray(singleFrame);

    % Remove dark cars.
    noDarkCars = imextendedmax(I, background); 

    % Remove lane markings and other non-disk shaped structures.
    noSmallStructures = imopen(noDarkCars, sedisk);

    % Remove small structures.
    noSmallStructures = bwareaopen(noSmallStructures, 150);

    % Get the area and centroid of each remaining object in the frame. The
    % object with the largest area is the light-colored car.  Create a copy
    % of the original frame and tag the car by changing the centroid pixel
    % value to red.
    taggedCars(:,:,:,k) = singleFrame;

    stats = regionprops(noSmallStructures, {'Centroid','Area'});
    if ~isempty([stats.Area])
        areaArray = [stats.Area];
        [junk,idx] = max(areaArray);
        c = stats(idx).Centroid;
        c = floor(fliplr(c));
        width = 2;
        row = c(1)-width:c(1)+width;
        col = c(2)-width:c(2)+width;
        taggedCars(row,col,1,k) = 0;
        taggedCars(row,col,2,k) = 145;
        taggedCars(row,col,3,k) = 25;
    end
end

%% Step 5: Visualize Results % Get the frame rate of the original video and use it to % see taggedCars in implay.

frameRate = reader.FrameRate; implay(taggedCars,frameRate);