Hands-On Image Processing with Python

Displaying the magnitude and the gradient on the same image

In the earlier example, the magnitude and direction of the edges were shown in different images. We can create an RGB image and set the R, G, and B values as follows to display both magnitude and direction in the same image:

With the same code as in the last example, we only replace the right bottom subplot code with the following code:

im = np.zeros((im.shape[0],im.shape[1],3))im[...,0] = im_mag*np.sin(im_ang)im[...,1] = im_mag*np.cos(im_ang)pylab.title(r'||grad||+$\theta$', size=30), pylab.imshow(im), pylab.axis('off')

And then, using a tiger image instead, we get the output shown ...