Realcat
update: major change
499e141
""" Organize some frequently used visualization functions. """
import cv2
import numpy as np
import matplotlib
import matplotlib.pyplot as plt
import copy
import seaborn as sns
# Plot junctions onto the image (return a separate copy)
def plot_junctions(input_image, junctions, junc_size=3, color=None):
"""
input_image: can be 0~1 float or 0~255 uint8.
junctions: Nx2 or 2xN np array.
junc_size: the size of the plotted circles.
"""
# Create image copy
image = copy.copy(input_image)
# Make sure the image is converted to 255 uint8
if image.dtype == np.uint8:
pass
# A float type image ranging from 0~1
elif image.dtype in [np.float32, np.float64, np.float] and image.max() <= 2.:
image = (image * 255.).astype(np.uint8)
# A float type image ranging from 0.~255.
elif image.dtype in [np.float32, np.float64, np.float] and image.mean() > 10.:
image = image.astype(np.uint8)
else:
raise ValueError("[Error] Unknown image data type. Expect 0~1 float or 0~255 uint8.")
# Check whether the image is single channel
if len(image.shape) == 2 or ((len(image.shape) == 3) and (image.shape[-1] == 1)):
# Squeeze to H*W first
image = image.squeeze()
# Stack to channle 3
image = np.concatenate([image[..., None] for _ in range(3)], axis=-1)
# Junction dimensions should be N*2
if not len(junctions.shape) == 2:
raise ValueError("[Error] junctions should be 2-dim array.")
# Always convert to N*2
if junctions.shape[-1] != 2:
if junctions.shape[0] == 2:
junctions = junctions.T
else:
raise ValueError("[Error] At least one of the two dims should be 2.")
# Round and convert junctions to int (and check the boundary)
H, W = image.shape[:2]
junctions = (np.round(junctions)).astype(np.int)
junctions[junctions < 0] = 0
junctions[junctions[:, 0] >= H, 0] = H-1 # (first dim) max bounded by H-1
junctions[junctions[:, 1] >= W, 1] = W-1 # (second dim) max bounded by W-1
# Iterate through all the junctions
num_junc = junctions.shape[0]
if color is None:
color = (0, 255., 0)
for idx in range(num_junc):
# Fetch one junction
junc = junctions[idx, :]
cv2.circle(image, tuple(np.flip(junc)), radius=junc_size,
color=color, thickness=3)
return image
# Plot line segements given junctions and line adjecent map
def plot_line_segments(input_image, junctions, line_map, junc_size=3,
color=(0, 255., 0), line_width=1, plot_survived_junc=True):
"""
input_image: can be 0~1 float or 0~255 uint8.
junctions: Nx2 or 2xN np array.
line_map: NxN np array
junc_size: the size of the plotted circles.
color: color of the line segments (can be string "random")
line_width: width of the drawn segments.
plot_survived_junc: whether we only plot the survived junctions.
"""
# Create image copy
image = copy.copy(input_image)
# Make sure the image is converted to 255 uint8
if image.dtype == np.uint8:
pass
# A float type image ranging from 0~1
elif image.dtype in [np.float32, np.float64, np.float] and image.max() <= 2.:
image = (image * 255.).astype(np.uint8)
# A float type image ranging from 0.~255.
elif image.dtype in [np.float32, np.float64, np.float] and image.mean() > 10.:
image = image.astype(np.uint8)
else:
raise ValueError("[Error] Unknown image data type. Expect 0~1 float or 0~255 uint8.")
# Check whether the image is single channel
if len(image.shape) == 2 or ((len(image.shape) == 3) and (image.shape[-1] == 1)):
# Squeeze to H*W first
image = image.squeeze()
# Stack to channle 3
image = np.concatenate([image[..., None] for _ in range(3)], axis=-1)
# Junction dimensions should be 2
if not len(junctions.shape) == 2:
raise ValueError("[Error] junctions should be 2-dim array.")
# Always convert to N*2
if junctions.shape[-1] != 2:
if junctions.shape[0] == 2:
junctions = junctions.T
else:
raise ValueError("[Error] At least one of the two dims should be 2.")
# line_map dimension should be 2
if not len(line_map.shape) == 2:
raise ValueError("[Error] line_map should be 2-dim array.")
# Color should be "random" or a list or tuple with length 3
if color != "random":
if not (isinstance(color, tuple) or isinstance(color, list)):
raise ValueError("[Error] color should have type list or tuple.")
else:
if len(color) != 3:
raise ValueError("[Error] color should be a list or tuple with length 3.")
# Make a copy of the line_map
line_map_tmp = copy.copy(line_map)
# Parse line_map back to segment pairs
segments = np.zeros([0, 4])
for idx in range(junctions.shape[0]):
# if no connectivity, just skip it
if line_map_tmp[idx, :].sum() == 0:
continue
# record the line segment
else:
for idx2 in np.where(line_map_tmp[idx, :] == 1)[0]:
p1 = np.flip(junctions[idx, :]) # Convert to xy format
p2 = np.flip(junctions[idx2, :]) # Convert to xy format
segments = np.concatenate((segments, np.array([p1[0], p1[1], p2[0], p2[1]])[None, ...]), axis=0)
# Update line_map
line_map_tmp[idx, idx2] = 0
line_map_tmp[idx2, idx] = 0
# Draw segment pairs
for idx in range(segments.shape[0]):
seg = np.round(segments[idx, :]).astype(np.int)
# Decide the color
if color != "random":
color = tuple(color)
else:
color = tuple(np.random.rand(3,))
cv2.line(image, tuple(seg[:2]), tuple(seg[2:]), color=color, thickness=line_width)
# Also draw the junctions
if not plot_survived_junc:
num_junc = junctions.shape[0]
for idx in range(num_junc):
# Fetch one junction
junc = junctions[idx, :]
cv2.circle(image, tuple(np.flip(junc)), radius=junc_size,
color=(0, 255., 0), thickness=3)
# Only plot the junctions which are part of a line segment
else:
for idx in range(segments.shape[0]):
seg = np.round(segments[idx, :]).astype(np.int) # Already in HW format.
cv2.circle(image, tuple(seg[:2]), radius=junc_size,
color=(0, 255., 0), thickness=3)
cv2.circle(image, tuple(seg[2:]), radius=junc_size,
color=(0, 255., 0), thickness=3)
return image
# Plot line segments given Nx4 or Nx2x2 line segments
def plot_line_segments_from_segments(input_image, line_segments, junc_size=3,
color=(0, 255., 0), line_width=1):
# Create image copy
image = copy.copy(input_image)
# Make sure the image is converted to 255 uint8
if image.dtype == np.uint8:
pass
# A float type image ranging from 0~1
elif image.dtype in [np.float32, np.float64, np.float] and image.max() <= 2.:
image = (image * 255.).astype(np.uint8)
# A float type image ranging from 0.~255.
elif image.dtype in [np.float32, np.float64, np.float] and image.mean() > 10.:
image = image.astype(np.uint8)
else:
raise ValueError("[Error] Unknown image data type. Expect 0~1 float or 0~255 uint8.")
# Check whether the image is single channel
if len(image.shape) == 2 or ((len(image.shape) == 3) and (image.shape[-1] == 1)):
# Squeeze to H*W first
image = image.squeeze()
# Stack to channle 3
image = np.concatenate([image[..., None] for _ in range(3)], axis=-1)
# Check the if line_segments are in (1) Nx4, or (2) Nx2x2.
H, W, _ = image.shape
# (1) Nx4 format
if len(line_segments.shape) == 2 and line_segments.shape[-1] == 4:
# Round to int32
line_segments = line_segments.astype(np.int32)
# Clip H dimension
line_segments[:, 0] = np.clip(line_segments[:, 0], a_min=0, a_max=H-1)
line_segments[:, 2] = np.clip(line_segments[:, 2], a_min=0, a_max=H-1)
# Clip W dimension
line_segments[:, 1] = np.clip(line_segments[:, 1], a_min=0, a_max=W-1)
line_segments[:, 3] = np.clip(line_segments[:, 3], a_min=0, a_max=W-1)
# Convert to Nx2x2 format
line_segments = np.concatenate(
[np.expand_dims(line_segments[:, :2], axis=1),
np.expand_dims(line_segments[:, 2:], axis=1)],
axis=1
)
# (2) Nx2x2 format
elif len(line_segments.shape) == 3 and line_segments.shape[-1] == 2:
# Round to int32
line_segments = line_segments.astype(np.int32)
# Clip H dimension
line_segments[:, :, 0] = np.clip(line_segments[:, :, 0], a_min=0, a_max=H-1)
line_segments[:, :, 1] = np.clip(line_segments[:, :, 1], a_min=0, a_max=W-1)
else:
raise ValueError("[Error] line_segments should be either Nx4 or Nx2x2 in HW format.")
# Draw segment pairs (all segments should be in HW format)
image = image.copy()
for idx in range(line_segments.shape[0]):
seg = np.round(line_segments[idx, :, :]).astype(np.int32)
# Decide the color
if color != "random":
color = tuple(color)
else:
color = tuple(np.random.rand(3,))
cv2.line(image, tuple(np.flip(seg[0, :])),
tuple(np.flip(seg[1, :])),
color=color, thickness=line_width)
# Also draw the junctions
cv2.circle(image, tuple(np.flip(seg[0, :])), radius=junc_size, color=(0, 255., 0), thickness=3)
cv2.circle(image, tuple(np.flip(seg[1, :])), radius=junc_size, color=(0, 255., 0), thickness=3)
return image
# Additional functions to visualize multiple images at the same time,
# e.g. for line matching
def plot_images(imgs, titles=None, cmaps='gray', dpi=100, size=6, pad=.5):
"""Plot a set of images horizontally.
Args:
imgs: a list of NumPy or PyTorch images, RGB (H, W, 3) or mono (H, W).
titles: a list of strings, as titles for each image.
cmaps: colormaps for monochrome images.
"""
n = len(imgs)
if not isinstance(cmaps, (list, tuple)):
cmaps = [cmaps] * n
figsize = (size*n, size*3/4) if size is not None else None
fig, ax = plt.subplots(1, n, figsize=figsize, dpi=dpi)
if n == 1:
ax = [ax]
for i in range(n):
ax[i].imshow(imgs[i], cmap=plt.get_cmap(cmaps[i]))
ax[i].get_yaxis().set_ticks([])
ax[i].get_xaxis().set_ticks([])
ax[i].set_axis_off()
for spine in ax[i].spines.values(): # remove frame
spine.set_visible(False)
if titles:
ax[i].set_title(titles[i])
fig.tight_layout(pad=pad)
def plot_keypoints(kpts, colors='lime', ps=4):
"""Plot keypoints for existing images.
Args:
kpts: list of ndarrays of size (N, 2).
colors: string, or list of list of tuples (one for each keypoints).
ps: size of the keypoints as float.
"""
if not isinstance(colors, list):
colors = [colors] * len(kpts)
axes = plt.gcf().axes
for a, k, c in zip(axes, kpts, colors):
a.scatter(k[:, 0], k[:, 1], c=c, s=ps, linewidths=0)
def plot_matches(kpts0, kpts1, color=None, lw=1.5, ps=4, indices=(0, 1), a=1.):
"""Plot matches for a pair of existing images.
Args:
kpts0, kpts1: corresponding keypoints of size (N, 2).
color: color of each match, string or RGB tuple. Random if not given.
lw: width of the lines.
ps: size of the end points (no endpoint if ps=0)
indices: indices of the images to draw the matches on.
a: alpha opacity of the match lines.
"""
fig = plt.gcf()
ax = fig.axes
assert len(ax) > max(indices)
ax0, ax1 = ax[indices[0]], ax[indices[1]]
fig.canvas.draw()
assert len(kpts0) == len(kpts1)
if color is None:
color = matplotlib.cm.hsv(np.random.rand(len(kpts0))).tolist()
elif len(color) > 0 and not isinstance(color[0], (tuple, list)):
color = [color] * len(kpts0)
if lw > 0:
# transform the points into the figure coordinate system
transFigure = fig.transFigure.inverted()
fkpts0 = transFigure.transform(ax0.transData.transform(kpts0))
fkpts1 = transFigure.transform(ax1.transData.transform(kpts1))
fig.lines += [matplotlib.lines.Line2D(
(fkpts0[i, 0], fkpts1[i, 0]), (fkpts0[i, 1], fkpts1[i, 1]),
zorder=1, transform=fig.transFigure, c=color[i], linewidth=lw,
alpha=a)
for i in range(len(kpts0))]
# freeze the axes to prevent the transform to change
ax0.autoscale(enable=False)
ax1.autoscale(enable=False)
if ps > 0:
ax0.scatter(kpts0[:, 0], kpts0[:, 1], c=color, s=ps, zorder=2)
ax1.scatter(kpts1[:, 0], kpts1[:, 1], c=color, s=ps, zorder=2)
def plot_lines(lines, line_colors='orange', point_colors='cyan',
ps=4, lw=2, indices=(0, 1)):
"""Plot lines and endpoints for existing images.
Args:
lines: list of ndarrays of size (N, 2, 2).
colors: string, or list of list of tuples (one for each keypoints).
ps: size of the keypoints as float pixels.
lw: line width as float pixels.
indices: indices of the images to draw the matches on.
"""
if not isinstance(line_colors, list):
line_colors = [line_colors] * len(lines)
if not isinstance(point_colors, list):
point_colors = [point_colors] * len(lines)
fig = plt.gcf()
ax = fig.axes
assert len(ax) > max(indices)
axes = [ax[i] for i in indices]
fig.canvas.draw()
# Plot the lines and junctions
for a, l, lc, pc in zip(axes, lines, line_colors, point_colors):
for i in range(len(l)):
line = matplotlib.lines.Line2D((l[i, 0, 0], l[i, 1, 0]),
(l[i, 0, 1], l[i, 1, 1]),
zorder=1, c=lc, linewidth=lw)
a.add_line(line)
pts = l.reshape(-1, 2)
a.scatter(pts[:, 0], pts[:, 1],
c=pc, s=ps, linewidths=0, zorder=2)
def plot_line_matches(kpts0, kpts1, color=None, lw=1.5, indices=(0, 1), a=1.):
"""Plot matches for a pair of existing images, parametrized by their middle point.
Args:
kpts0, kpts1: corresponding middle points of the lines of size (N, 2).
color: color of each match, string or RGB tuple. Random if not given.
lw: width of the lines.
indices: indices of the images to draw the matches on.
a: alpha opacity of the match lines.
"""
fig = plt.gcf()
ax = fig.axes
assert len(ax) > max(indices)
ax0, ax1 = ax[indices[0]], ax[indices[1]]
fig.canvas.draw()
assert len(kpts0) == len(kpts1)
if color is None:
color = matplotlib.cm.hsv(np.random.rand(len(kpts0))).tolist()
elif len(color) > 0 and not isinstance(color[0], (tuple, list)):
color = [color] * len(kpts0)
if lw > 0:
# transform the points into the figure coordinate system
transFigure = fig.transFigure.inverted()
fkpts0 = transFigure.transform(ax0.transData.transform(kpts0))
fkpts1 = transFigure.transform(ax1.transData.transform(kpts1))
fig.lines += [matplotlib.lines.Line2D(
(fkpts0[i, 0], fkpts1[i, 0]), (fkpts0[i, 1], fkpts1[i, 1]),
zorder=1, transform=fig.transFigure, c=color[i], linewidth=lw,
alpha=a)
for i in range(len(kpts0))]
# freeze the axes to prevent the transform to change
ax0.autoscale(enable=False)
ax1.autoscale(enable=False)
def plot_color_line_matches(lines, correct_matches=None,
lw=2, indices=(0, 1)):
"""Plot line matches for existing images with multiple colors.
Args:
lines: list of ndarrays of size (N, 2, 2).
correct_matches: bool array of size (N,) indicating correct matches.
lw: line width as float pixels.
indices: indices of the images to draw the matches on.
"""
n_lines = len(lines[0])
colors = sns.color_palette('husl', n_colors=n_lines)
np.random.shuffle(colors)
alphas = np.ones(n_lines)
# If correct_matches is not None, display wrong matches with a low alpha
if correct_matches is not None:
alphas[~np.array(correct_matches)] = 0.2
fig = plt.gcf()
ax = fig.axes
assert len(ax) > max(indices)
axes = [ax[i] for i in indices]
fig.canvas.draw()
# Plot the lines
for a, l in zip(axes, lines):
# Transform the points into the figure coordinate system
transFigure = fig.transFigure.inverted()
endpoint0 = transFigure.transform(a.transData.transform(l[:, 0]))
endpoint1 = transFigure.transform(a.transData.transform(l[:, 1]))
fig.lines += [matplotlib.lines.Line2D(
(endpoint0[i, 0], endpoint1[i, 0]),
(endpoint0[i, 1], endpoint1[i, 1]),
zorder=1, transform=fig.transFigure, c=colors[i],
alpha=alphas[i], linewidth=lw) for i in range(n_lines)]
def plot_color_lines(lines, correct_matches, wrong_matches,
lw=2, indices=(0, 1)):
"""Plot line matches for existing images with multiple colors:
green for correct matches, red for wrong ones, and blue for the rest.
Args:
lines: list of ndarrays of size (N, 2, 2).
correct_matches: list of bool arrays of size N with correct matches.
wrong_matches: list of bool arrays of size (N,) with correct matches.
lw: line width as float pixels.
indices: indices of the images to draw the matches on.
"""
# palette = sns.color_palette()
palette = sns.color_palette("hls", 8)
blue = palette[5] # palette[0]
red = palette[0] # palette[3]
green = palette[2] # palette[2]
colors = [np.array([blue] * len(l)) for l in lines]
for i, c in enumerate(colors):
c[np.array(correct_matches[i])] = green
c[np.array(wrong_matches[i])] = red
fig = plt.gcf()
ax = fig.axes
assert len(ax) > max(indices)
axes = [ax[i] for i in indices]
fig.canvas.draw()
# Plot the lines
for a, l, c in zip(axes, lines, colors):
# Transform the points into the figure coordinate system
transFigure = fig.transFigure.inverted()
endpoint0 = transFigure.transform(a.transData.transform(l[:, 0]))
endpoint1 = transFigure.transform(a.transData.transform(l[:, 1]))
fig.lines += [matplotlib.lines.Line2D(
(endpoint0[i, 0], endpoint1[i, 0]),
(endpoint0[i, 1], endpoint1[i, 1]),
zorder=1, transform=fig.transFigure, c=c[i],
linewidth=lw) for i in range(len(l))]
def plot_subsegment_matches(lines, subsegments, lw=2, indices=(0, 1)):
""" Plot line matches for existing images with multiple colors and
highlight the actually matched subsegments.
Args:
lines: list of ndarrays of size (N, 2, 2).
subsegments: list of ndarrays of size (N, 2, 2).
lw: line width as float pixels.
indices: indices of the images to draw the matches on.
"""
n_lines = len(lines[0])
colors = sns.cubehelix_palette(start=2, rot=-0.2, dark=0.3, light=.7,
gamma=1.3, hue=1, n_colors=n_lines)
fig = plt.gcf()
ax = fig.axes
assert len(ax) > max(indices)
axes = [ax[i] for i in indices]
fig.canvas.draw()
# Plot the lines
for a, l, ss in zip(axes, lines, subsegments):
# Transform the points into the figure coordinate system
transFigure = fig.transFigure.inverted()
# Draw full line
endpoint0 = transFigure.transform(a.transData.transform(l[:, 0]))
endpoint1 = transFigure.transform(a.transData.transform(l[:, 1]))
fig.lines += [matplotlib.lines.Line2D(
(endpoint0[i, 0], endpoint1[i, 0]),
(endpoint0[i, 1], endpoint1[i, 1]),
zorder=1, transform=fig.transFigure, c='red',
alpha=0.7, linewidth=lw) for i in range(n_lines)]
# Draw matched subsegment
endpoint0 = transFigure.transform(a.transData.transform(ss[:, 0]))
endpoint1 = transFigure.transform(a.transData.transform(ss[:, 1]))
fig.lines += [matplotlib.lines.Line2D(
(endpoint0[i, 0], endpoint1[i, 0]),
(endpoint0[i, 1], endpoint1[i, 1]),
zorder=1, transform=fig.transFigure, c=colors[i],
alpha=1, linewidth=lw) for i in range(n_lines)]