textToImage.py

#! -*- coding: utf-8 -*-

from PIL import Image, ImageDraw, ImageFont

def reverseColor(r,g,b):
  return (255-r,255-g,255-b)

def grayscaleColor(r,g,b):
  a=(r+g+b)/3
  return (a,a,a)

text="Hello World!"

#textColor =(255,255,0)  # RGB Yellow
#textBackgroundColor=(255,0,0) # RGB Red

textX=400 # text width im pixels
textY=100 # text height in pixels
textTopLeftX=0
textTopLeftY=0

image=Image.open("input.png")
(imgx,imgy)=image.size

font=ImageFont.load_default()
(width, height)=font.getsize(text)
textImage=font.getmask(text)
pixels=image.load()
for y in range(imgy):
  by=int(height*(y-textTopLeftY)/textY +0.5)
  if by>=0 and by<height:
    for x in range(imgx):
      bx=int(width*(x-textTopLeftX)/textX+0.5)
      if bx>=0 and bx<width:
        if textImage.getpixel((bx,by))==0:  #text background
          #pass #transparent background
          #pixels[x,y[=textBackgroundColor
          (r,g,b,a)=pixels[x,y]
          pixels[x,y]=grayscaleColor(r,g,b)
        else:
          (r,g,b,a)=pixels[x,y]
          pixels[x,y]=reverseColor(r,g,b)
         
image.save("output.png","PNG")