Some Stuff

This commit is contained in:
Michael Mikovsky
2025-02-06 11:13:44 -07:00
parent e9cd8968f2
commit 8287c33b20
3 changed files with 247 additions and 0 deletions
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import cv2
import numpy as np
def process_video(video_path, scale_factor=0.5, min_area=500):
"""
Process video for motion detection.
Args:
video_path: Path to input video
output_path: Path to save processed video
scale_factor: Factor to downscale the frames
min_area: Minimum contour area to be considered as motion
"""
# Open video
cap = cv2.VideoCapture(video_path)
if not cap.isOpened():
raise ValueError("Error opening video file")
# Get video properties
frame_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
frame_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
fps = int(cap.get(cv2.CAP_PROP_FPS))
# Create video writer
# fourcc = cv2.VideoWriter_fourcc(*'mp4v')
# out = cv2.VideoWriter(output_path, fourcc, fps, (frame_width, frame_height))
# Read first frame
ret, prev_frame = cap.read()
if not ret:
raise ValueError("Error reading first frame")
# Process first frame
prev_gray = cv2.cvtColor(prev_frame, cv2.COLOR_BGR2GRAY)
prev_small = cv2.resize(prev_gray, None, fx=scale_factor, fy=scale_factor)
while True:
# Read current frame
ret, curr_frame = cap.read()
if not ret:
break
# Convert to grayscale
curr_gray = cv2.cvtColor(curr_frame, cv2.COLOR_BGR2GRAY)
# Downscale
curr_small = cv2.resize(curr_gray, None, fx=scale_factor, fy=scale_factor)
# Calculate absolute difference
frame_diff = cv2.absdiff(curr_small, prev_small)
# Apply threshold to difference
_, thresh = cv2.threshold(frame_diff, 50, 255, cv2.THRESH_BINARY)
# Dilate to fill in holes
kernel = np.ones((3,3), np.uint8)
dilated = cv2.dilate(thresh, kernel, iterations=2)
# Scale back up to original size
motion_mask = cv2.resize(dilated, (frame_width, frame_height))
# Find contours
contours, _ = cv2.findContours(motion_mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
# Draw motion areas on original frame
for contour in contours:
if cv2.contourArea(contour) > min_area:
x, y, w, h = cv2.boundingRect(contour)
cv2.rectangle(curr_frame, (x, y), (x+w, y+h), (0, 255, 0), 2)
# Write frame to output video
cv2.imshow("e",curr_frame)
# Exit if 'q' is pressed
if cv2.waitKey(30) & 0xFF == ord('q'):
break
# Update previous frame
prev_small = curr_small
# Release resources
cap.release()
cv2.destroyAllWindows()
def main():
# Example usage
input_video = 0
try:
process_video(input_video)
print("Motion detection completed successfully")
except Exception as e:
print(f"Error processing video: {str(e)}")
if __name__ == "__main__":
main()
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import numpy as np
import cv2
def detect_feature_points(frame, max_corners=1000):
"""
Detect good features to track in the frame.
"""
# Convert frame to grayscale if it's not already
if len(frame.shape) == 3:
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
else:
gray = frame
# Detect corners using Shi-Tomasi method
corners = cv2.goodFeaturesToTrack(
gray,
maxCorners=max_corners,
qualityLevel=0.001,
minDistance=10,
blockSize=7
)
return corners
def calculate_optical_flow(prev_frame, curr_frame, prev_points):
"""
Calculate optical flow for given points between two frames.
"""
# Convert frames to grayscale
if len(prev_frame.shape) == 3:
prev_gray = cv2.cvtColor(prev_frame, cv2.COLOR_BGR2GRAY)
curr_gray = cv2.cvtColor(curr_frame, cv2.COLOR_BGR2GRAY)
else:
prev_gray = prev_frame
curr_gray = curr_frame
# Calculate optical flow using Lucas-Kanade method
curr_points, status, error = cv2.calcOpticalFlowPyrLK(
prev_gray,
curr_gray,
prev_points,
None,
winSize=(15, 15),
maxLevel=2,
criteria=(cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 10, 0.03)
)
# Filter out points where flow wasn't found
good_new = curr_points[status == 1]
good_old = prev_points[status == 1]
return good_new, good_old
def estimate_camera_motion(prev_points, curr_points, threshold=5.0):
"""
Estimate camera motion and identify outlier points.
Returns mask of points that don't follow the dominant motion pattern.
"""
# Calculate motion vectors
motion_vectors = curr_points - prev_points
# Calculate median motion as an estimate of camera motion
median_motion = np.median(motion_vectors, axis=0)
# Calculate the difference from median motion for each point
motion_differences = np.linalg.norm(motion_vectors - median_motion, axis=1)
# Calculate the median absolute deviation (MAD)
mad = np.median(np.abs(motion_differences - np.median(motion_differences)))
# Points with motion significantly different from the camera motion
# are considered outliers (using modified z-score)
outliers_mask = motion_differences > (threshold * mad)
return outliers_mask
def analyze_motion(video_path):
"""
Analyze motion in video and detect objects moving differently from camera motion.
"""
cap = cv2.VideoCapture(video_path)
# Read first frame
ret, prev_frame = cap.read()
if not ret:
raise ValueError("Could not read video")
prev_points = None
while True:
ret, curr_frame = cap.read()
if not ret:
break
# Detect initial points
if prev_points is None:
prev_points = detect_feature_points(prev_frame)
elif curr_points.shape[0] < 600:
prev_points = detect_feature_points(prev_frame)
print(prev_points.shape)
# Calculate optical flow
curr_points, prev_points_matched = calculate_optical_flow(
prev_frame, curr_frame, prev_points
)
if len(curr_points) > 0 and len(prev_points_matched) > 0:
# Find points not moving with camera
outliers_mask = estimate_camera_motion(prev_points_matched, curr_points)
# Visualize results
frame_vis = curr_frame.copy()
# Draw all tracked points
for i, (new, old) in enumerate(zip(curr_points, prev_points_matched)):
a, b = new.ravel()
c, d = old.ravel()
# Draw line between old and new position
color = (0, 0, 255) if outliers_mask[i] else (0, 255, 0)
cv2.line(frame_vis, (int(c), int(d)), (int(a), int(b)), color, 2)
cv2.circle(frame_vis, (int(a), int(b)), 3, color, -1)
cv2.imshow('Frame', frame_vis)
# Exit if 'q' is pressed
if cv2.waitKey(30) & 0xFF == ord('q'):
break
# Update for next iteration
prev_frame = curr_frame.copy()
prev_points = curr_points.reshape(-1, 1, 2)
cap.release()
cv2.destroyAllWindows()
if __name__ == "__main__":
# Example usage
video_path = 0
analyze_motion(video_path)
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import cv2
cap = cv2.VideoCapture(0)
while True:
ret, frame = cap.read()
with open('/dev/fb0', 'rb+') as buf:
buf.write(frame)
cap.release()