grayscale-conversion

name	grayscale-conversion
description	Convert RGB images to grayscale using OpenCV (cv2) in Python. Use this skill when the user needs to convert color images to grayscale for image processing, template matching, or analysis.

Grayscale Image Conversion

Convert RGB/BGR images to grayscale using OpenCV.

Python Code

import cv2

img = cv2.imread("input.png")
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
cv2.imwrite("input.png", gray)  # overwrite in-place

Batch Conversion

import cv2
import glob

for path in sorted(glob.glob("/root/keyframes_*.png")):
    img = cv2.imread(path)
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    cv2.imwrite(path, gray)

Notes

• OpenCV reads images in BGR format, so use COLOR_BGR2GRAY
• Writing a grayscale image back with cv2.imwrite produces a single-channel PNG
• Grayscale conversion is often a prerequisite for template matching with cv2.matchTemplate