convert-frames-to-grayscale-and-count-objects

name	Convert Frames to Grayscale and Count Objects
description	Processes all extracted keyframes by converting them to grayscale, then counts coins, enemies, and turtles in each frame using template matching. Generates a CSV file with frame-by-frame object counts. Use this as the main analysis pipeline after keyframe extraction.

import os
import cv2
import subprocess
import csv
from pathlib import Path

# Step 3: Convert all keyframes to grayscale in-place
keyframes_dir = "/root"
keyframe_files = sorted([f for f in os.listdir(keyframes_dir) if f.startswith("keyframes_") and f.endswith(".png")])

for keyframe_file in keyframe_files:
    keyframe_path = os.path.join(keyframes_dir, keyframe_file)
    img = cv2.imread(keyframe_path)
    gray_img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    cv2.imwrite(keyframe_path, gray_img)
    print(f"Converted {keyframe_file} to grayscale")

# Step 4, 5: Count objects in each frame
results = []

for keyframe_file in keyframe_files:
    keyframe_path = os.path.join(keyframes_dir, keyframe_file)
    
    # Extract frame number from filename (e.g., "keyframes_001.png" -> 1)
    frame_id = keyframe_file.replace("keyframes_", "").replace(".png", "")
    frame_id_int = int(frame_id)
    
    # Count coins
    coin_result = subprocess.run(
        ["python", "-m", "object_counter", "--tool", "count", "--input_image", keyframe_path, "--object_image", "/root/coin.png"],
        capture_output=True,
        text=True
    )
    coin_count = int(coin_result.stdout.strip())
    
    # Count enemies
    enemy_result = subprocess.run(
        ["python", "-m", "object_counter", "--tool", "count", "--input_image", keyframe_path, "--object_image", "/root/enemy.png"],
        capture_output=True,
        text=True
    )
    enemy_count = int(enemy_result.stdout.strip())
    
    # Count turtles
    turtle_result = subprocess.run(
        ["python", "-m", "object_counter", "--tool", "count", "--input_image", keyframe_path, "--object_image", "/root/turtle.png"],
        capture_output=True,
        text=True
    )
    turtle_count = int(turtle_result.stdout.strip())
    
    results.append({
        "frame_id": f"/root/keyframes_{frame_id}.png",
        "coins": coin_count,
        "enemies": enemy_count,
        "turtles": turtle_count
    })
    
    print(f"Frame {frame_id}: coins={coin_count}, enemies={enemy_count}, turtles={turtle_count}")

# Step 6: Generate CSV file
csv_path = "/root/counting_results.csv"
with open(csv_path, "w", newline="") as csvfile:
    fieldnames = ["frame_id", "coins", "enemies", "turtles"]
    writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
    
    writer.writeheader()
    for row in results:
        writer.writerow(row)

print(f"CSV file generated at {csv_path}")