CODEWITHSUNDEEP
pythonimageimage-processingpython-imaging-library
EvenDance
EvenDance

Reputation: 93

Python PIL getdata() method doesn't return a tuple

I have a question about the Python module PIL:

Whenever I call the getdata() method on an image, I get something weird returned.

from PIL import Image

# Histogram class to get the data
class Histogram:
    def __init__(self, image):
        image.convert("RGB")
        pixel_value_list = list(image.getdata())
        print(pixel_value_list[1])

image = Image.open("lenna.gif")
histogram = Histogram(image)

But I do not get a tuple printed to the console, but somehow 45...

Why does the list(image.getdata()) not return a list with tuples but a list entirely made of integers?

Upvotes: 5

Views: 12755

Answers (1)

Michiel Overtoom
Michiel Overtoom

Reputation: 1619

If you open a palettized file (like a GIF), and print the list of pixels via .getdata(), you'll get a list of indexes into the palette, e.g.:

im = Image.open("composplot.gif")
print(list(im.getdata()))

Output:

[0, 0, 0, 0, 0, 0, 0, 0, 6, 223, 0, 0, 46, 219, 195, ...]

However, if your convert the palettized image to a RGB image, you'll get a list of (r,g,b) tuples. Example:

im = Image.open("composplot.gif")
imrgb = im.convert("RGB")
print(list(imrgb.getdata()))

Output:

[(255, 255, 255), (255, 255, 255), (216, 216, 216), (8, 8, 8), (191, 191, 191), (255, 255, 255), ...]

Upvotes: 4

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