# Visualize module for plotting and handling predictions
import os
import pandas as pd
import matplotlib
import matplotlib.pyplot as plt
import matplotlib.patches as patches
from skimage import io
import numpy as np
[docs]def plot_prediction_and_targets(image, predictions, targets, image_name, savedir):
"""Plot an image, its predictions, and its ground truth targets for debugging"""
prediction_df = format_boxes(predictions)
plot, ax = plot_predictions(image, prediction_df)
target_df = format_boxes(targets, scores=False)
plot = add_annotations(plot, ax, target_df)
plot.savefig("{}/{}.png".format(savedir, image_name), dpi=300)
return "{}/{}.png".format(savedir, image_name)
[docs]def plot_prediction_dataframe(df, root_dir, ground_truth=None, savedir=None):
"""For each row in dataframe, call plot predictions. For multi-class labels, boxes will be colored by labels. Ground truth boxes will all be same color, regardless of class.
Args:
df: a pandas dataframe with image_path, xmin, xmax, ymin, ymax and label columns
root_dir: relative dir to look for image names from df.image_path
ground_truth: an optional pandas dataframe in same format as df holding ground_truth boxes
savedir: save the plot to an optional directory path.
Returns:
None: side-effect plots are saved or generated and viewed
"""
for name, group in df.groupby("image_path"):
image = io.imread("{}/{}".format(root_dir, name))
plot, ax = plot_predictions(image, group)
if ground_truth is not None:
annotations = ground_truth[ground_truth.image_path == name]
plot = add_annotations(plot, ax, annotations)
if savedir:
plot.savefig("{}/{}.png".format(savedir, os.path.splitext(name)[0]))
[docs]def plot_predictions(image, df):
"""channel order is channels first for pytorch"""
#Create a numeric index for coloring
df['numeric'] = df['label'].astype('category').cat.codes
#What size does the figure need to be in inches to fit the image?
dpi=300
height, width, nbands = image.shape
figsize = width / float(dpi), height / float(dpi)
fig, ax = plt.subplots(figsize=figsize)
ax.imshow(image)
for index, row in df.iterrows():
xmin = row["xmin"]
ymin = row["ymin"]
width = row["xmax"] - xmin
height = row["ymax"] - ymin
color = label_to_color(row["numeric"])
rect = create_box(xmin=xmin, ymin=ymin, height=height, width=width, color=color)
ax.add_patch(rect)
# no axis show up
plt.axis('off')
return fig, ax
[docs]def create_box(xmin, ymin, height, width, color="cyan", linewidth=0.5):
rect = patches.Rectangle((xmin, ymin),
height,
width,
linewidth=linewidth,
edgecolor=color,
fill=False)
return rect
[docs]def add_annotations(plot, ax, annotations):
"""Add annotations to an already created visuale.plot_predictions
Args:
plot: matplotlib figure object
ax: maplotlib axes object
annotations: pandas dataframe of bounding box annotations
Returns:
plot: matplotlib figure object
"""
for index, row in annotations.iterrows():
xmin = row["xmin"]
ymin = row["ymin"]
width = row["xmax"] - xmin
height = row["ymax"] - ymin
rect = create_box(xmin=xmin,
ymin=ymin,
height=height,
width=width,
color="orange")
ax.add_patch(rect)
return plot
[docs]def label_to_color(label):
color_dict = {}
colors = [
list((matplotlib.colors.hsv_to_rgb([x, 1.0, 1.0])).astype(int))
for x in np.arange(0, 1, 1.0 / 80)
]
for index, color in enumerate(colors):
color_dict[index] = color
# hand pick the first few colors
color_dict[0] = "cyan"
color_dict[1] = "tomato"
color_dict[2] = "blue"
color_dict[3] = "limegreen"
color_dict[4] = "orchid"
color_dict[5] = "crimson"
color_dict[6] = "peru"
color_dict[7] = "dodgerblue"
color_dict[8] = "gold"
color_dict[9] = "blueviolet"
return color_dict[label]