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pythongraphicsrgbpixel

How to read the RGB value of a given pixel in Python?

If I open an image with open("image.jpg"), how can I get the RGB values of a pixel assuming I have the coordinates of the pixel?

Then, how can I do the reverse of this? Starting with a blank graphic, 'write' a pixel with a certain RGB value?

I would prefer if I didn't have to download any additional libraries.

Solution

  • It's probably best to use the Python Image Library to do this which I'm afraid is a separate download.

    The easiest way to do what you want is via the load() method on the Image object which returns a pixel access object which you can manipulate like an array:

    from PIL import Image

im = Image.open('dead_parrot.jpg') # Can be many different formats.
pix = im.load()
print im.size  # Get the width and hight of the image for iterating over
print pix[x,y]  # Get the RGBA Value of the a pixel of an image
pix[x,y] = value  # Set the RGBA Value of the image (tuple)
im.save('alive_parrot.png')  # Save the modified pixels as .png

    Alternatively, look at ImageDraw which gives a much richer API for creating images.