Reading, saving, and displaying an image using scikit-image

The next code block uses the imread() function from scikit-image to read an image in a numpy ndarray of type uint8 (8-bit unsigned integer). Hence, the pixel values will be in between 0 and 255. Then it converts (changes the image type or mode, which will be discussed shortly) the colored RGB image into an HSV image using the hsv2rgb() function from the Image.color module. Next, it changes the saturation (colorfulness) to a constant value for all of the pixels by keeping the hue and value channels unchanged. The image is then converted back into RGB mode with the rgb2hsv() function to create a new image, which is then saved and displayed:

im = imread("../images/parrot.png")     # read image from disk, provide the correct path
print(im.shape, im.dtype, type(im)) 
# (362, 486, 3) uint8 <class 'numpy.ndarray'>
hsv = color.rgb2hsv(im) # from RGB to HSV color space
hsv[:, :, 1] = 0.5 # change the saturation
im1 = color.hsv2rgb(hsv) # from HSV back to RGB
imsave('../images/parrot_hsv.png', im1) # save image to disk
im = imread("../images/parrot_hsv.png")
plt.axis('off'), imshow(im), show()

The next figure shows the output of the previous code—a new image with changed saturation:

We can use the scikit-image viewer module also to display an image in a pop-up window, as shown in the following code:

viewer = viewer.ImageViewer(im)
viewer.show()