How to convert a string to an image?

Marco- picture Marco- · Jul 25, 2013 · Viewed 55.5k times · Source

I started to learn python a week ago and want to write a small program that converts a email to a image (.png) so that it can be shared on forums without risking to get lots of spam mails.

It seems like the python standard library doesn't contain a module that can do that but I've found out that there's a PIL module for it (PIL.ImageDraw).

My problem is that I can't seem to get it working.

So basically my questions are:

  1. How to draw a text onto a image.
  2. How to create a blank (white) image
  3. Is there a way to do this without actually creating a file so that I can show it in a GUI before saving it?

Current Code:

import Image
import ImageDraw
import ImageFont

def getSize(txt, font):
    testImg = Image.new('RGB', (1, 1))
    testDraw = ImageDraw.Draw(testImg)
    return testDraw.textsize(txt, font)

if __name__ == '__main__':

    fontname = "Arial.ttf"
    fontsize = 11   
    text = "[email protected]"
    
    colorText = "black"
    colorOutline = "red"
    colorBackground = "white"


    font = ImageFont.truetype(fontname, fontsize)
    width, height = getSize(text, font)
    img = Image.new('RGB', (width+4, height+4), colorBackground)
    d = ImageDraw.Draw(img)
    d.text((2, height/2), text, fill=colorText, font=font)
    d.rectangle((0, 0, width+3, height+3), outline=colorOutline)
    
    img.save("D:/image.png")

Answer

Jan Spurny picture Jan Spurny · Jul 25, 2013
  1. use ImageDraw.text - but it doesn't do any formating, it just prints string at the given location

    img = Image.new('RGB', (200, 100))
    d = ImageDraw.Draw(img)
    d.text((20, 20), 'Hello', fill=(255, 0, 0))
    

    to find out the text size:

    text_width, text_height = d.textsize('Hello')
    
  2. When creating image, add an aditional argument with the required color (white):

    img = Image.new('RGB', (200, 100), (255, 255, 255))
    
  3. until you save the image with Image.save method, there would be no file. Then it's only a matter of a proper transformation to put it into your GUI's format for display. This can be done by encoding the image into an in-memory image file:

    import cStringIO
    s = cStringIO.StringIO()
    img.save(s, 'png')
    in_memory_file = s.getvalue()
    

    or if you use python3:

    import io
    s = io.BytesIO()
    img.save(s, 'png')
    in_memory_file = s.getvalue()
    

    this can be then send to GUI. Or you can send direct raw bitmap data:

    raw_img_data = img.tostring()