How to use PIL to make all white pixels transparent?

image, python, python-imaging-library

Solution

You need to make the following changes:

- append a tuple `(255, 255, 255, 0)` and not a list `[255, 255, 255, 0]`

- use `img.putdata(newData)`

This is the working code:

from PIL import Image

img = Image.open('img.png')
img = img.convert("RGBA")
datas = img.getdata()

newData = []
for item in datas:
    if item[0] == 255 and item[1] == 255 and item[2] == 255:
        newData.append((255, 255, 255, 0))
    else:
        newData.append(item)

img.putdata(newData)
img.save("img2.png", "PNG")

Problem

I'm trying to make all white pixels transparent using the Python Image Library. (I'm a C hacker trying to learn python so be gentle) I've got the conversion working (at least the pixel values look correct) but I can't figure out how to convert the list into a buffer to re-create the image. Here's the code ``` img = Image.open('img.png') imga = img.convert("RGBA") datas = imga.getdata() newData = list() for item in datas: if item[0] == 255 and item[1] == 255 and item[2] == 255: newData.append([255, 255, 255, 0]) else: newData.append(item) imgb = Image.frombuffer("RGBA", imga.size, newData, "raw", "RGBA", 0, 1) imgb.save("img2.png", "PNG") ```

Original source

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