When classifying images one is often interested in seeing the areas that supports and/or contradicts a classification. plot_image_explanation() will take the result of an image explanation and highlight the areas found relevant to each label in the explanation. The highlighting can either be done by blocking the parts of the image not related to the classification, or by encircling and colouring the areas that influence the explanation.

plot_image_explanation(
  explanation,
  which = 1,
  threshold = 0.02,
  show_negative = FALSE,
  display = "outline",
  fill_alpha = 0.3,
  outline_col = c("blue", "red"),
  block_col = "grey"
)

Arguments

explanation

The explanation created with an image_explainer

which

The case in explanation to illustrate. plot_image_explanation only supports showing one case at a time.

threshold

The lowest absolute weighted superpixels to include

show_negative

Should areas that contradicts the prediction also be shown

display

How should the areas be shown? Either outline or block

fill_alpha

In case of display = 'outline' how opaque should the area colour be?

outline_col

A vector of length 2 giving the colour for supporting and contradicting areas respectively if display = 'outline'

block_col

The colour to use for the unimportant areas if display = 'block'

Value

A ggplot object

Examples


if (FALSE) {
# load precalculated explanation as it takes a long time to create
explanation <- .load_image_example()

# Default
plot_image_explanation(explanation)

# Block out background instead
plot_image_explanation(explanation, display = 'block')

# Show negatively correlated areas as well
plot_image_explanation(explanation, show_negative = TRUE)
}