A special Python image submodule for beginners.
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.
Note
This module uses the Cartesian coordinate system, where the origin is at the lower-left corner instead of the upper-right and the order is x, y instead of row, column.
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’)
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
Changing size resizes the picture. >>> picture.size = (45, 30)
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 /= 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
Bases: object
A 2-D picture made up of pixels.
Examples
Load an image from a file >>> from skimage import novice >>> from skimage import data >>> picture = novice.open(data.data_dir + ‘/chelsea.png’)
Load an image from a URL. URL must start with http(s):// or ftp(s):// >>> picture = novice.open(‘http://scikit-image.org/_static/img/logo.png‘)
Create a blank 100 pixel wide, 200 pixel tall white image >>> pic = Picture.from_size((100, 200), color=(255, 255, 255))
Use numpy to make an RGB byte array (shape is height x width x 3) >>> import numpy as np >>> data = np.zeros(shape=(200, 100, 3), dtype=np.uint8) >>> data[:, :, 0] = 255 # Set red component to maximum >>> pic = Picture(array=data)
Get the bottom-left pixel >>> pic[0, 0] Pixel(red=255, green=0, blue=0, alpha=255)
Get the top row of the picture >>> pic[:, pic.height-1] Picture(100 x 1)
Set the bottom-left pixel to black >>> pic[0, 0] = (0, 0, 0)
Set the top row to red >>> pic[:, pic.height-1] = (255, 0, 0)
Attributes
| path | The path to the picture. |
| array | Image data stored as numpy array. |
| xy_array | Image data stored as numpy array with origin at the bottom-left. |
The transparency component of the pixel (0-255).
Image data stored as numpy array.
The blue component of the pixel (0-255).
The image format of the picture.
Return a Picture of the specified size and a uniform color.
| Parameters: | size : tuple
color : tuple or str
|
|---|
The green component of the pixel (0-255).
The height of the picture.
True if the picture has changed.
The path to the picture.
The red component of the pixel (0-255).
The RGB color components of the pixel (3 values 0-255).
The RGBA color components of the pixel (4 values 0-255).
Saves the picture to the given path.
| Parameters: | path : str
|
|---|
Display the image.
The size (width, height) of the picture.
The width of the picture.
Image data stored as numpy array with origin at the bottom-left.
| skimage.novice.open(path) | Return Picture object from the given image path. |
