Make images come alive with scikit-image

Image Processing in Python

Rebeca Gonzalez

Data Engineer

What is image processing?

Operations on images and videos to:

Enhance an image
Extract useful information
Analyze it and make decisions

Image of a group of friends where faces are detected

What is image processing?

Operations to on images and videos to:

Enhance an image
Extract useful information
Analyze it and make decisions

Image that shows the original image of a man with a camera taking a photo, next to the thresholded result of that image and down below this two, the histogram of the thresholded image

Applications

Medical image analysis
Artificial intelligence
Image restoration and enhancement
Geospatial computing
Surveillance
Robotic vision
Automotive safety
And many more...

Image that shows 6 image processing applications: Face detection, spatial image processing, medial image analysis, geospatial computing and automotive safety

Purposes

Visualization:
- Objects that are not visible
Image sharpening and restoration
- A better image
Image retrieval
- Seek for the image of interest
Measurement of pattern
- Measures various objects
Image Recognition
- Distinguish objects in an image

Intro to scikit-image

Easy to use
Makes use of Machine Learning
Out of the box complex algorithms

What is an image?

A photo of a deer resting in the grass next to another image of a zoomed in part. Showing the pixels of the photo

What is an image?

MAtriz of pixels intensities of grayscale image

Images in scikit-image

from skimage import data

rocket_image = data.rocket()

Rocket

RGB channels

Original image of a cat above 3 images showing the RGB colors

Grayscaled images

Grayscale image next to intensities matrix

RGB vs Grayscale

from skimage import color
grayscale = color.rgb2gray(original)

rgb = color.gray2rgb(grayscale)

Colores astronaut next to grayscaled astronaut

Visualizing images in the course

Don't worry about Matplotlib!

def show_image(image, title='Image', cmap_type='gray'):
    plt.imshow(image, cmap=cmap_type)    
    plt.title(title)
    plt.axis('off')
    plt.show()

Visualizing images in the course

from skimage import color
grayscale = color.rgb2gray(original)

show_image(grayscale, "Grayscale")

Astronaut

Let's practice!

Image Processing in Python