kolena.workflow.visualization

Colormap(fade_low_activation=True)

Bases: ABC

A Colormap maps a pixel intensity to RGBA.

fade_low_activation: bool = fade_low_activation instance-attribute

Fades out the regions with low activation by applying zero alpha value if set True; otherwise, activation map is shown as is without any fading applied. By default, it's set to True. This option makes the overlay visualization better by highlighting only the important regions.

red(intensity) abstractmethod

Maps a grayscale pixel intensity to color red: [0, 255]

green(intensity) abstractmethod

Maps a grayscale pixel intensity to color green: [0, 255]

blue(intensity) abstractmethod

Maps a grayscale pixel intensity to color blue: [0, 255]

alpha(intensity)

Maps the grayscale pixel intensity to alpha: [0, 255]. If fade_low_activation is False, then it returns the maximum alpha value.

ColormapJet(fade_low_activation=True)

Bases: Colormap

The MATLAB "Jet" color palette is a standard palette used for scientific and mathematical data.

It is defined as a linear ramp between the following colours: "#00007F", "blue", "#007FFF", "cyan", "#7FFF7F", "yellow", "#FF7F00", "red", "#7F0000"

colorize_activation_map(activation_map, colormap=ColormapJet())

Applies the specified colormap to the activation map.

Parameters:

Name	Type	Description	Default
activation_map	ndarray	A 2D numpy array, shaped (h, w) or (h, w, 1), of the activation map in np.uint8 or float ranging [0, 1].	required
colormap	Colormap	The colormap used to colorize the input activation map. Defaults to the MATLAB "Jet" colormap.	ColormapJet()

Returns:

Type	Description
ndarray	The colorized activation map in RGBA format, in (h, w, 4) shape.

encode_png(image, mode)

Encodes an image into an in-memory PNG file that is represented as binary data. It is used when you want to upload a 2 or 3-dimensional image in a NumPy array format to cloud.

It can be used in conjunction with colorized_activation_map when uploading an activation map.

Parameters:

Name	Type	Description	Default
image	ndarray	A 2D or 3D NumPy array, shaped either (h, w), (h, w, 1), (h, w, 3), or (h, w, 4)	required
mode	str	A PIL mode	required

Returns:

Type	Description
BytesIO	The in-memory PNG file represented as binary data.