PIL images are saving in grayscale

Question

I'm trying to generate some fractal images and I can do it fine. However, I have some problems when saving the images, because it saves them in grayscale instead of the colours. When I open them in python, it shows the right colours.

The code is as follows

from PIL import Image
import ImageDraw
from scipy import misc
from array import *
import matplotlib.pyplot as plt
import scipy

image = Image.new("L",(SIZE, SIZE)) # create a image SIZE x SIZE
d = ImageDraw.Draw(image)
#iterate over x and y, setting a col value for each pixel
d.point((x, y), col ) # it then colors the point (x,y)
image.save("beta"+str(alpha)+".png", "PNG")

I'm using macOS X, Python 2.7.5.

Answer 1

You are creating images in L , or Luminance mode. That means they are greyscale images, one band of colour.

You need to use the RGB mode instead:

image = Image.new("RGB", (SIZE, SIZE))

This does require you to use tuples of (R, G, B) values when specifying pixels, not a simple integer. The ImageDraw module does support setting colours using strings as well ( '#rrggbb' and related).

You don't show us how you define col in your code, so it is hard to state if you are using the correct format for an RGB image.