lino / src /models /aggregator /utils /visual_track.py
algohunt
initial_commit
c295391
# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the license found in the
# LICENSE file in the root directory of this source tree.
import cv2
import torch
import numpy as np
import os
def color_from_xy(x, y, W, H, cmap_name="hsv"):
"""
Map (x, y) -> color in (R, G, B).
1) Normalize x,y to [0,1].
2) Combine them into a single scalar c in [0,1].
3) Use matplotlib's colormap to convert c -> (R,G,B).
You can customize step 2, e.g., c = (x + y)/2, or some function of (x, y).
"""
import matplotlib.cm
import matplotlib.colors
x_norm = x / max(W - 1, 1)
y_norm = y / max(H - 1, 1)
# Simple combination:
c = (x_norm + y_norm) / 2.0
cmap = matplotlib.cm.get_cmap(cmap_name)
# cmap(c) -> (r,g,b,a) in [0,1]
rgba = cmap(c)
r, g, b = rgba[0], rgba[1], rgba[2]
return (r, g, b) # in [0,1], RGB order
def get_track_colors_by_position(tracks_b, vis_mask_b=None, image_width=None, image_height=None, cmap_name="hsv"):
"""
Given all tracks in one sample (b), compute a (N,3) array of RGB color values
in [0,255]. The color is determined by the (x,y) position in the first
visible frame for each track.
Args:
tracks_b: Tensor of shape (S, N, 2). (x,y) for each track in each frame.
vis_mask_b: (S, N) boolean mask; if None, assume all are visible.
image_width, image_height: used for normalizing (x, y).
cmap_name: for matplotlib (e.g., 'hsv', 'rainbow', 'jet').
Returns:
track_colors: np.ndarray of shape (N, 3), each row is (R,G,B) in [0,255].
"""
S, N, _ = tracks_b.shape
track_colors = np.zeros((N, 3), dtype=np.uint8)
if vis_mask_b is None:
# treat all as visible
vis_mask_b = torch.ones(S, N, dtype=torch.bool, device=tracks_b.device)
for i in range(N):
# Find first visible frame for track i
visible_frames = torch.where(vis_mask_b[:, i])[0]
if len(visible_frames) == 0:
# track is never visible; just assign black or something
track_colors[i] = (0, 0, 0)
continue
first_s = int(visible_frames[0].item())
# use that frame's (x,y)
x, y = tracks_b[first_s, i].tolist()
# map (x,y) -> (R,G,B) in [0,1]
r, g, b = color_from_xy(x, y, W=image_width, H=image_height, cmap_name=cmap_name)
# scale to [0,255]
r, g, b = int(r * 255), int(g * 255), int(b * 255)
track_colors[i] = (r, g, b)
return track_colors
def visualize_tracks_on_images(
images,
tracks,
track_vis_mask=None,
out_dir="track_visuals_concat_by_xy",
image_format="CHW", # "CHW" or "HWC"
normalize_mode="[0,1]",
cmap_name="hsv", # e.g. "hsv", "rainbow", "jet"
frames_per_row=4, # New parameter for grid layout
save_grid=True, # Flag to control whether to save the grid image
):
"""
Visualizes frames in a grid layout with specified frames per row.
Each track's color is determined by its (x,y) position
in the first visible frame (or frame 0 if always visible).
Finally convert the BGR result to RGB before saving.
Also saves each individual frame as a separate PNG file.
Args:
images: torch.Tensor (S, 3, H, W) if CHW or (S, H, W, 3) if HWC.
tracks: torch.Tensor (S, N, 2), last dim = (x, y).
track_vis_mask: torch.Tensor (S, N) or None.
out_dir: folder to save visualizations.
image_format: "CHW" or "HWC".
normalize_mode: "[0,1]", "[-1,1]", or None for direct raw -> 0..255
cmap_name: a matplotlib colormap name for color_from_xy.
frames_per_row: number of frames to display in each row of the grid.
save_grid: whether to save all frames in one grid image.
Returns:
None (saves images in out_dir).
"""
if len(tracks.shape) == 4:
tracks = tracks.squeeze(0)
images = images.squeeze(0)
if track_vis_mask is not None:
track_vis_mask = track_vis_mask.squeeze(0)
import matplotlib
matplotlib.use("Agg") # for non-interactive (optional)
os.makedirs(out_dir, exist_ok=True)
S = images.shape[0]
_, N, _ = tracks.shape # (S, N, 2)
# Move to CPU
images = images.cpu().clone()
tracks = tracks.cpu().clone()
if track_vis_mask is not None:
track_vis_mask = track_vis_mask.cpu().clone()
# Infer H, W from images shape
if image_format == "CHW":
# e.g. images[s].shape = (3, H, W)
H, W = images.shape[2], images.shape[3]
else:
# e.g. images[s].shape = (H, W, 3)
H, W = images.shape[1], images.shape[2]
# Pre-compute the color for each track i based on first visible position
track_colors_rgb = get_track_colors_by_position(
tracks, # shape (S, N, 2)
vis_mask_b=track_vis_mask if track_vis_mask is not None else None,
image_width=W,
image_height=H,
cmap_name=cmap_name,
)
# We'll accumulate each frame's drawn image in a list
frame_images = []
for s in range(S):
# shape => either (3, H, W) or (H, W, 3)
img = images[s]
# Convert to (H, W, 3)
if image_format == "CHW":
img = img.permute(1, 2, 0) # (H, W, 3)
# else "HWC", do nothing
img = img.numpy().astype(np.float32)
# Scale to [0,255] if needed
if normalize_mode == "[0,1]":
img = np.clip(img, 0, 1) * 255.0
elif normalize_mode == "[-1,1]":
img = (img + 1.0) * 0.5 * 255.0
img = np.clip(img, 0, 255.0)
# else no normalization
# Convert to uint8
img = img.astype(np.uint8)
# For drawing in OpenCV, convert to BGR
img_bgr = cv2.cvtColor(img, cv2.COLOR_RGB2BGR)
# Draw each visible track
cur_tracks = tracks[s] # shape (N, 2)
if track_vis_mask is not None:
valid_indices = torch.where(track_vis_mask[s])[0]
else:
valid_indices = range(N)
cur_tracks_np = cur_tracks.numpy()
for i in valid_indices:
x, y = cur_tracks_np[i]
pt = (int(round(x)), int(round(y)))
# track_colors_rgb[i] is (R,G,B). For OpenCV circle, we need BGR
R, G, B = track_colors_rgb[i]
color_bgr = (int(B), int(G), int(R))
cv2.circle(img_bgr, pt, radius=3, color=color_bgr, thickness=-1)
# Convert back to RGB for consistent final saving:
img_rgb = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2RGB)
# Save individual frame
frame_path = os.path.join(out_dir, f"frame_{s:04d}.png")
# Convert to BGR for OpenCV imwrite
frame_bgr = cv2.cvtColor(img_rgb, cv2.COLOR_RGB2BGR)
cv2.imwrite(frame_path, frame_bgr)
frame_images.append(img_rgb)
# Only create and save the grid image if save_grid is True
if save_grid:
# Calculate grid dimensions
num_rows = (S + frames_per_row - 1) // frames_per_row # Ceiling division
# Create a grid of images
grid_img = None
for row in range(num_rows):
start_idx = row * frames_per_row
end_idx = min(start_idx + frames_per_row, S)
# Concatenate this row horizontally
row_img = np.concatenate(frame_images[start_idx:end_idx], axis=1)
# If this row has fewer than frames_per_row images, pad with black
if end_idx - start_idx < frames_per_row:
padding_width = (frames_per_row - (end_idx - start_idx)) * W
padding = np.zeros((H, padding_width, 3), dtype=np.uint8)
row_img = np.concatenate([row_img, padding], axis=1)
# Add this row to the grid
if grid_img is None:
grid_img = row_img
else:
grid_img = np.concatenate([grid_img, row_img], axis=0)
out_path = os.path.join(out_dir, "tracks_grid.png")
# Convert back to BGR for OpenCV imwrite
grid_img_bgr = cv2.cvtColor(grid_img, cv2.COLOR_RGB2BGR)
cv2.imwrite(out_path, grid_img_bgr)
print(f"[INFO] Saved color-by-XY track visualization grid -> {out_path}")
print(f"[INFO] Saved {S} individual frames to {out_dir}/frame_*.png")