Loading an image, adding layers, manipulating layers

basic_napari_example

import napari
import numpy as np
from skimage import data
from skimage.color import rgb2gray


# Convert the astronaut image to a grayscale
astro_im = rgb2gray(data.astronaut())

# Display the astronaut image and also display its negative in a new layer
viewer = napari.view_image(astro_im, name='astronaut')
viewer.add_image(astro_im*-1, name='negative')


# Put the two images next to each other as a grid
viewer.grid.enabled = True

# The two layers are in a list:
viewer.layers

# What is in this?
viewer.layers[0].__dir__()


# The name of the layers
[x.name for x in viewer.layers]



# Disable both layers then enabel the first one (the original image)
viewer.layers[0].visible = False
viewer.layers[1].visible = False
viewer.layers[0].visible = True


# The data the comprise the first layer are here:
viewer.layers[0].data

# We can invert it to make it a negative image
viewer.layers[0].data =  viewer.layers[0].data * -1

# Image looks blank because the contrast range is now wrong.
# Therefore we reset the contrast limits:
viewer.layers[0].reset_contrast_limits()


# Flip the raw data up/down
viewer.layers[0].data = np.flipud(viewer.layers[0].data)

import napari
import numpy as np
from skimage import data
from skimage.color import rgb2gray


# Convert the astronaut image to a grayscale
astro_im = rgb2gray(data.astronaut())

# Display the astronaut image and also display its negative in a new layer
viewer = napari.view_image(astro_im, name='astronaut')
viewer.add_image(astro_im*-1, name='negative')


# Put the two images next to each other as a grid
viewer.grid.enabled = True

# The two layers are in a list:
viewer.layers

# What is in this?
viewer.layers[0].__dir__()


# The name of the layers
[x.name for x in viewer.layers]



# Disable both layers then enabel the first one (the original image)
viewer.layers[0].visible = False
viewer.layers[1].visible = False
viewer.layers[0].visible = True


# The data the comprise the first layer are here:
viewer.layers[0].data

# We can invert it to make it a negative image
viewer.layers[0].data =  viewer.layers[0].data * -1

# Image looks blank because the contrast range is now wrong.
# Therefore we reset the contrast limits:
viewer.layers[0].reset_contrast_limits()


# Flip the raw data up/down
viewer.layers[0].data = np.flipud(viewer.layers[0].data)


# Invert again and change the colormap
viewer.layers[0].data =  viewer.layers[0].data * -1
viewer.layers[0].reset_contrast_limits()
viewer.layers[0].colormap = "inferno"

# Manually alter contrast
viewer.layers[0].contrast_limits = [0, 0.75]

# Enable the upper, negative image
viewer.layers[1].visible = True



# Invert again and change the colormap
viewer.layers[0].data =  viewer.layers[0].data * -1
viewer.layers[0].reset_contrast_limits()
viewer.layers[0].colormap = "inferno"

# Manually alter contrast
viewer.layers[0].contrast_limits = [0, 0.75]

# Enable the upper, negative image
viewer.layers[1].visible = True