module-skimage.novice

skimage.novice

A special Python image submodule for beginners.

Description

skimage.novice provides a simple image manipulation interface for beginners. It allows for easy loading, manipulating, and saving of image files.

This module is primarily intended for teaching and differs significantly from the normal, array-oriented image functions used by scikit-image.

Examples

We can create a Picture object open opening an image file:

>>> from skimage import novice
>>> from skimage import data
>>> picture = novice.open(data.data_dir + '/chelsea.png')

We can display pictures (after running this command, close the window to access the prompt again):

>>> picture.show()  

Pictures know their format:

>>> picture.format
'png'

... and where they came from:

>>> picture.path.endswith('chelsea.png')
True

... and their size:

>>> picture.size
(451, 300)
>>> picture.width
451

As a reminder, we can preview the picture with our earlier command:

>>> picture.show()  

Changing size resizes the picture.

>>> picture.size = (45, 30)

We can preview the changes we made to the picture with the compare command:

>>> picture.compare()  

You can iterate over pixels, which have RGB values between 0 and 255, and know their location in the picture.

>>> for pixel in picture:
...     if (pixel.red > 128) and (pixel.x < picture.width):
...         pixel.red = pixel.red / 2

Pictures know if they’ve been modified from the original file

>>> picture.modified
True
>>> print(picture.path)
None

Pictures can be indexed like arrays

>>> picture[0:20, 0:20] = (0, 0, 0)

Saving the picture updates the path attribute, format, and modified state.

>>> picture.save('save-demo.jpg')
>>> picture.path.endswith('save-demo.jpg')
True
>>> picture.format
'jpeg'
>>> picture.modified
False

An image can also be restored to its original state after modification:

>>> picture[0:20, 0:20] = (0, 0, 0)
>>> picture.compare()  
>>> picture.reset()
>>> picture.compare()  

skimage.novice.open(path)	Return Picture object from the given image path.
skimage.novice.Picture([path, array, xy_array])	A 2-D picture made up of pixels.