How to check whether a JPEG image is color or gray scale using only Python stdlib

Question

I have to write a test case in Python to check whether a jpg image is in color or grayscale. Can anyone please let me know if there is any way to do it with out installing extra libraries like OpenCV?

Answer 1

You can check every pixel to see if it is grayscale (R == G == B)

from PIL import Image

def is_grey_scale(img_path):
    img = Image.open(img_path).convert('RGB')
    w, h = img.size
    for i in range(w):
        for j in range(h):
            r, g, b = img.getpixel((i,j))
            if r != g != b: 
                return False
    return True