Uses pil to stamp and image with a license banner

stamp_image.py

# stanp a license bar at the bottom of an image

from PIL import Image, ImageFont, ImageDraw
import settings

def stamp_image(in_filepath, out_filepath,text):
    im = Image.open(in_filepath)

    # get size
    original_size = im.size
    o_width = original_size[0]
    o_height = original_size[1]

    # calc additional space size
    line = 15 # height per line
    add_size = (len(text) / (o_width/10)) * line # chars per line

    # min size
    if add_size < 20:
        add_size = 20

    new_size = (im.size[0], im.size[1] + add_size)

    # create blank image with 50px space at the bottom.
    im2 = Image.new("RGBA", new_size, 'Black')
    im2.paste(im, (0,0))

    # write copywrite text
    draw_word_wrap(img = im2,
                   text = text,
                   xpos = 5,
                   ypos = im.size[1]+5,
                   max_width = im2.size[0]-5,
                   fill='White',
                   font=ImageFont.load_default())

    # save the image
    im2.save(out_filepath, "JPEG")

def draw_word_wrap(img, text, xpos=0, ypos=0, max_width=130, fill=(0,0,0), font=None):
    '''Draw the given ``text`` to the x and y position of the image, using
    the minimum length word-wrapping algorithm to restrict the text to
    a pixel width of ``max_width.``
    '''
    draw = ImageDraw.Draw(img)
    text_size_x, text_size_y = draw.textsize(text, font=font)
    remaining = max_width
    space_width, space_height = draw.textsize(' ', font=font)
    # use this list as a stack, push/popping each line
    output_text = []
    # split on whitespace...
    for word in text.split(None):
        word_width, word_height = draw.textsize(word, font=font)
        if word_width + space_width > remaining:
            output_text.append(word)
            remaining = max_width - word_width
        else:
            if not output_text:
                output_text.append(word)
            else:
                output = output_text.pop()
                output += ' %s' % word
                output_text.append(output)
            remaining = remaining - (word_width + space_width)
    for text in output_text:
        draw.text((xpos, ypos), text, font=font, fill=fill)
        ypos += text_size_y