Get pixel's RGB using PIL

问题

Is it possible to get the RGB color of a pixel using PIL? I'm using this code:

im = Image.open("image.gif")
pix = im.load()
print(pix[1,1])

However, it only outputs a number (e.g. 0 or 1) and not three numbers (e.g. 60,60,60 for R,G,B). I guess I'm not understanding something about the function. I'd love some explanation.

Thanks a lot.

回答1:

Yes, this way:

im = Image.open('image.gif')
rgb_im = im.convert('RGB')
r, g, b = rgb_im.getpixel((1, 1))

print(r, g, b)
(65, 100, 137)

The reason you were getting a single value before with pix[1, 1] is because GIF pixels refer to one of the 256 values in the GIF color palette.

See also this SO post: Python and PIL pixel values different for GIF and JPEG and this PIL Reference page contains more information on the convert() function.

By the way, your code would work just fine for .jpg images.

回答2:

GIFs store colors as one of x number of possible colors in a palette. Read about the gif limited color palette. So PIL is giving you the palette index, rather than the color information of that palette color.

Edit: Removed link to a blog post solution that had a typo. Other answers do the same thing without the typo.

回答3:

An alternative to converting the image is to create an RGB index from the palette.

from PIL import Image

def chunk(seq, size, groupByList=True):
    """Returns list of lists/tuples broken up by size input"""
    func = tuple
    if groupByList:
        func = list
    return [func(seq[i:i + size]) for i in range(0, len(seq), size)]


def getPaletteInRgb(img):
    """
    Returns list of RGB tuples found in the image palette
    :type img: Image.Image
    :rtype: list[tuple]
    """
    assert img.mode == 'P', "image should be palette mode"
    pal = img.getpalette()
    colors = chunk(pal, 3, False)
    return colors

# Usage
im = Image.open("image.gif")
pal = getPalletteInRgb(im)

回答4:

Not PIL, but imageio.imread might still be interesting:

import imageio
im = scipy.misc.imread('um_000000.png', flatten=False, mode='RGB')
im = imageio.imread('Figure_1.png', pilmode='RGB')
print(im.shape)

gives

(480, 640, 3)

so it is (height, width, channels). So the pixel at position (x, y) is

color = tuple(im[y][x])
r, g, b = color

Outdated

scipy.misc.imread is deprecated in SciPy 1.0.0 (thanks for the reminder, fbahr!)

来源：https://stackoverflow.com/questions/11064786/get-pixels-rgb-using-pil

标签

python

image

python-imaging-library

rgb

pixel