We will be flipping the SciPy Lena image—all in the name of science, of course, or at least as a demo. In addition to flipping the image, we will slice it and apply a mask to it.
The steps are as follows:
Flip the Lena array around the vertical axis using the following code:
plt.imshow(lena[:,::-1])
Take a slice out of the image and plot it. In this step, we will take a look at the shape of the Lena array. The shape is a tuple representing the dimensions of the array. The following code effectively selects the top-left quadrant of the Playboy picture:
plt.imshow(lena[:lena.shape[0]/2,:lena.shape[1]/2])
Apply a mask to the image by finding all the values in the Lena array that are even (this is just arbitrary for demo purposes). Copy the array and change the even values to
0
. This has the effect of putting lots of blue dots on the image (dark spots if you are looking at a black-and-white image):mask = lena % 2 == 0 masked_lena = lena.copy() masked_lena[mask] = 0
All...