OpenCV 对象跟踪输入格式

Question

I'm working with approximately 5000 images per sample (+- 100 samples) taken by a high speed camera.

Converting them all to video files would take quite some time.

My question is: is it possible to apply object tracking to a sorted array of images?

My understanding is that the OpenCV tracking algorithms extracts each frame from the provided video file, tracks the requested object(s) and compares the result with the previous frame to determine if it is indeed the same object.

Short version: Is it possible to provide frames instead of a video file to the OpenCV tracking algorithms?

Answer 1

With few modifications you can modify Object Tracking using OpenCV to work with a sequence of images.

The following code applies tracking on images sequence in a folder (the video related code is commented):

import cv2
import cv2
import os
import glob
import sys

# https://www.quora.com/How-can-I-read-multiple-images-in-Python-presented-in-a-folder
img_dir = "C:/Images"  # Enter Directory of all images 
data_path = os.path.join(img_dir, "*.tif") #Assume images are in tiff format
img_files = glob.glob(data_path)

# Display image for testing:
##############################
#for f1 in img_files:
#    img = cv2.imread(f1)
#    cv2.imshow('img', img)
#    cv2.waitKey(1000)

#cv2.destroyAllWindows()
##############################


# https://www.learnopencv.com/object-tracking-using-opencv-cpp-python/

(major_ver, minor_ver, subminor_ver) = (cv2.__version__).split('.')

# Set up tracker.
# Instead of MIL, you can also use

tracker_types = ['BOOSTING', 'MIL','KCF', 'TLD', 'MEDIANFLOW', 'GOTURN', 'MOSSE', 'CSRT']
tracker_type = tracker_types[2]

if int(minor_ver) < 3:
    tracker = cv2.Tracker_create(tracker_type)
else:
    if tracker_type == 'BOOSTING':
        tracker = cv2.TrackerBoosting_create()
    if tracker_type == 'MIL':
        tracker = cv2.TrackerMIL_create()
    if tracker_type == 'KCF':
        tracker = cv2.TrackerKCF_create()
    if tracker_type == 'TLD':
        tracker = cv2.TrackerTLD_create()
    if tracker_type == 'MEDIANFLOW':
        tracker = cv2.TrackerMedianFlow_create()
    if tracker_type == 'GOTURN':
        tracker = cv2.TrackerGOTURN_create()
    if tracker_type == 'MOSSE':
        tracker = cv2.TrackerMOSSE_create()
    if tracker_type == "CSRT":
        tracker = cv2.TrackerCSRT_create()

# Read video
#video = cv2.VideoCapture("videos/chaplin.mp4")

# Exit if video not opened.
#if not video.isOpened():
#    print "Could not open video"
#    sys.exit()

if not img_dir:
    print("Images folder is empty")
    sys.exit()

# Read first image
frame = cv2.imread(img_files[0])

if frame is None:
    print("Cannot read image file")
    sys.exit()

# Read first frame.
#ok, frame = video.read()
#if not ok:
#    print 'Cannot read video file'
#    sys.exit()

# Define an initial bounding box
bbox = (287, 23, 86, 320)

# Uncomment the line below to select a different bounding box
bbox = cv2.selectROI(frame, False)

# Initialize tracker with first frame and bounding box
ok = tracker.init(frame, bbox)

#while True:

# Iterate image files instead of reading from a video file
for f1 in img_files:
    frame = cv2.imread(f1)

    # Read a new frame
    #ok, frame = video.read()
    #if not ok:
    #    break

    # Start timer
    timer = cv2.getTickCount()

    # Update tracker
    ok, bbox = tracker.update(frame)

    # Calculate Frames per second (FPS)
    #fps = cv2.getTickFrequency() / (cv2.getTickCount() - timer);

    fps = 30 # We don't know the fps from the set of images

    # Draw bounding box
    if ok:
        # Tracking success
        p1 = (int(bbox[0]), int(bbox[1]))
        p2 = (int(bbox[0] + bbox[2]), int(bbox[1] + bbox[3]))
        cv2.rectangle(frame, p1, p2, (255,0,0), 2, 1)
    else:
        # Tracking failure
        cv2.putText(frame, "Tracking failure detected", (100,80), cv2.FONT_HERSHEY_SIMPLEX, 0.75,(0,0,255),2)

    # Display tracker type on frame
    cv2.putText(frame, tracker_type + " Tracker", (100,20), cv2.FONT_HERSHEY_SIMPLEX, 0.75, (50,170,50),2);

    # Display FPS on frame
    cv2.putText(frame, "FPS : " + str(int(fps)), (100,50), cv2.FONT_HERSHEY_SIMPLEX, 0.75, (50,170,50), 2);

    # Display result
    cv2.imshow("Tracking", frame)

    # Exit if ESC pressed
    k = cv2.waitKey(1) & 0xff 

    if k == 27:
        break