[Python] Plot a Gaussian and overlay with an image

    x,y = np.random.multivariate_normal(mean, cov, 9000000).T
    x = x + center_x
    y = y + center_y

    heatmap, xedges, yedges = np.histogram2d(x, y, bins=(640, 480), range=[[0, 640], [0, 480]])
    extent = [0, 640, 0, 480]

    # convert heatmap to image
    heatmap = heatmap / max(heatmap.flatten())
    print max(heatmap.flatten())
    heatmap_im = Image.fromarray(np.uint8(cm.jet(np.transpose(heatmap))*255))
 
    blend_im = Image.blend(im.convert("RGBA"), heatmap_im, 0.4)
    blend_im.save("blend.png", "PNG")