In [1]:

    

using Images


    

In [2]:

    

function images_derivatives(img₁,img₂)

    k_x = [-1.0 1.0;-1.0 1.0]
    k_y = [-1.0 -1.0;1.0 1.0]
    k_t = ones(Float64,2,2)
    
    f_x = imfilter(img₁,k_x) + imfilter(img₂,k_x)
    f_y = imfilter(img₁,k_y) + imfilter(img₂,k_y)
    f_t = imfilter(img₁,-k_t) + imfilter(img₂,k_t)

    return f_x,f_y,f_t
end

function optical_flowHS(img₁,img₂,u₀,v₀,α::Number,tol=1e-7)
    iter = 7 
    # initialize u,v
    u = u₀ 
    v = v₀
    # compute the derivatives
    f_x,f_y,f_t = images_derivatives(img₁,img₂)
    
    # compute the average images
    k_av = [1/12 1/6 1/12;1/6 0 1/6;1/12 1/6 1/12]

    #while norm()

    for i in 1:iter
        
        #compute the local average of the flow vectors
        u_av = imfilter(u,k_av)
        v_av = imfilter(v,k_av)
        
        P = f_x .* u_av + f_y .* v_av + f_t
        D = α + (f_x).^2 + (f_y).^2
        
        
        u = u_av - f_x .* (P ./ D)
        v = v_av - f_y .* (P ./ D)

    end

    return u,v
end


    

    
Out[2]:





optical_flowHS (generic function with 2 methods)

In [3]:

    

img₁ = imread("/home/elsuizo/Optical_flow/Images/hamburg_tax1.jpg")


    

    
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In [4]:

    

img₂ = imread("/home/elsuizo/Optical_flow/Images/hamburg_tax2.jpg")


    

    
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In [5]:

    

u₀ = zeros(img₁)


    

    
Out[5]:

In [6]:

    

v₀ = zeros(img₂)


    

    
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In [7]:

    

u,v = optical_flowHS(img₁,img₂,u₀,v₀,0.3)


    

    
Out[7]:





(
Gray Image with:
  data: 442x442 Array{Gray{Float64},2}
  properties:
    spatialorder:  x y
    pixelspacing:  1 1
    IMcs: Gray,

Gray Image with:
  data: 442x442 Array{Gray{Float64},2}
  properties:
    spatialorder:  x y
    pixelspacing:  1 1
    IMcs: Gray)

In [14]:

    

using PyPlot


    

    




INFO: Loading help data...
Warning: using PyPlot.imread in module Main conflicts with an existing identifier.

In [15]:

    

imshow(separate(u),cmap="gray")


    

    













    
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PyObject <matplotlib.image.AxesImage object at 0xabaf892c>

In [16]:

    

imshow(separate(v),cmap="gray")


    

    













    
Out[16]:





PyObject <matplotlib.image.AxesImage object at 0xab4d03cc>

In [29]:

    

img1 = imread("/home/elsuizo/images/Webcam/omni1.jpg");
img1_gray = convert(Array{Gray},img1);


    

In [30]:

    

img2 = imread("/home/elsuizo/images/Webcam/omni2.jpg");
img2_gray = convert(Array{Gray},img2);


    

In [31]:

    

u0 = zeros(img1_gray);
v0 = zeros(img2_gray);


    

In [44]:

    

@time u1,v1 = optical_flowHS(img1_gray,img2_gray,u0,v0,.3);


    

    




elapsed time: 2.433506576 seconds (359506652 bytes allocated, 65.28% gc time)

In [40]:

    




    

    




Warning: using Winston.hold in module Main conflicts with an existing identifier.
Warning: using Winston.ylim in module Main conflicts with an existing identifier.
Warning: using Winston.plot in module Main conflicts with an existing identifier.
Warning: using Winston.semilogx in module Main conflicts with an existing identifier.
Warning: using Winston.scatter in module Main conflicts with an existing identifier.
Warning: using Winston.spy in module Main conflicts with an existing identifier.
Warning: using Winston.xlim in module Main conflicts with an existing identifier.
Warning: using Winston.grid in module Main conflicts with an existing identifier.
Warning: using Winston.stem in module Main conflicts with an existing identifier.
Warning: using Winston.Image in module Main conflicts with an existing identifier.
Warning: using Winston.gcf in module Main conflicts with an existing identifier.
Warning: using Winston.ylabel in module Main conflicts with an existing identifier.
Warning: using Winston.text in module Main conflicts with an existing identifier.
Warning: using Winston.semilogy in module Main conflicts with an existing identifier.
Warning: using Winston.xlabel in module Main conflicts with an existing identifier.
Warning: using Winston.errorbar in module Main conflicts with an existing identifier.
Warning: using Winston.title in module Main conflicts with an existing identifier.
Warning: using Winston.loglog in module Main conflicts with an existing identifier.
Warning: using Winston.figure in module Main conflicts with an existing identifier.
Warning: using Winston.savefig in module Main conflicts with an existing identifier.
Warning: using Winston.legend in module Main conflicts with an existing identifier.

In [45]:

    

import Winston


    

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