PIL - 在图像上绘制多行文本

Question

我尝试在图像底部添加文本，实际上我已经做到了，但如果我的文本比图像宽度长，它会从两侧切割，为了简化我希望文本多行如果它长于图像宽度。这是我的代码：

FOREGROUND = (255, 255, 255)
WIDTH = 375
HEIGHT = 50
TEXT = 'Chyba najwyższy czas zadać to pytanie na śniadanie \n Chyba najwyższy czas zadać to pytanie na śniadanie'
font_path = '/Library/Fonts/Arial.ttf'
font = ImageFont.truetype(font_path, 14, encoding='unic')
text = TEXT.decode('utf-8')
(width, height) = font.getsize(text)

x = Image.open('media/converty/image.png')
y = ImageOps.expand(x,border=2,fill='white')
y = ImageOps.expand(y,border=30,fill='black')

w, h = y.size
bg = Image.new('RGBA', (w, 1000), "#000000")

W, H = bg.size
xo, yo = (W-w)/2, (H-h)/2
bg.paste(y, (xo, 0, xo+w, h))
draw = ImageDraw.Draw(bg)
draw.text(((w - width)/2, w), text, font=font, fill=FOREGROUND)


bg.show()
bg.save('media/converty/test.png')

Answer 1

您可以使用textwrap.wrap 将text 分解为一个字符串列表，每个字符串最长为width 个字符：

import textwrap
lines = textwrap.wrap(text, width=40)
y_text = h
for line in lines:
    width, height = font.getsize(line)
    draw.text(((w - width) / 2, y_text), line, font=font, fill=FOREGROUND)
    y_text += height

Answer 2

text = textwrap.fill("test ",width=35)
self.draw.text((x, y), text, font=font, fill="Black")

Answer 3

您可以使用PIL.ImageDraw.Draw.multiline_text()。

draw.multiline_text((WIDTH, HEIGHT), TEXT, fill=FOREGROUND, font=font)

您甚至可以使用相同的参数名称设置 spacing 或 align。

Answer 4

接受的答案在不测量字体的情况下换行（最多 40 个字符，无论字体大小和框宽是多少），因此结果只是近似值，可能很容易使框填满或不足。

这是一个正确解决问题的简单库： https://gist.github.com/turicas/1455973

Answer 5

所有关于 textwrap 用法的建议都无法确定非等宽字体的正确宽度（如 Arial，在主题示例代码中使用）。

我编写了简单的帮助类来包装有关实际字体大小的文本：

class TextWrapper(object):
    """ Helper class to wrap text in lines, based on given text, font
        and max allowed line width.
    """

    def __init__(self, text, font, max_width):
        self.text = text
        self.text_lines = [
            ' '.join([w.strip() for w in l.split(' ') if w])
            for l in text.split('\n')
            if l
        ]
        self.font = font
        self.max_width = max_width

        self.draw = ImageDraw.Draw(
            Image.new(
                mode='RGB',
                size=(100, 100)
            )
        )

        self.space_width = self.draw.textsize(
            text=' ',
            font=self.font
        )[0]

    def get_text_width(self, text):
        return self.draw.textsize(
            text=text,
            font=self.font
        )[0]

    def wrapped_text(self):
        wrapped_lines = []
        buf = []
        buf_width = 0

        for line in self.text_lines:
            for word in line.split(' '):
                word_width = self.get_text_width(word)

                expected_width = word_width if not buf else \
                    buf_width + self.space_width + word_width

                if expected_width <= self.max_width:
                    # word fits in line
                    buf_width = expected_width
                    buf.append(word)
                else:
                    # word doesn't fit in line
                    wrapped_lines.append(' '.join(buf))
                    buf = [word]
                    buf_width = word_width

            if buf:
                wrapped_lines.append(' '.join(buf))
                buf = []
                buf_width = 0

        return '\n'.join(wrapped_lines)

示例用法：

wrapper = TextWrapper(text, image_font_intance, 800)
wrapped_text = wrapper.wrapped_text()

它可能不是超级快，因为它会逐字呈现整个文本，以确定字宽。但大多数情况下应该没问题。

Answer 6

对于使用 unutbu 的 trick 的完整工作示例（使用 Python 3.6 和 Pillow 5.3.0 测试）：

from PIL import Image, ImageDraw, ImageFont
import textwrap

def draw_multiple_line_text(image, text, font, text_color, text_start_height):
    '''
    From unutbu on [python PIL draw multiline text on image](https://stackoverflow.com/a/7698300/395857)
    '''
    draw = ImageDraw.Draw(image)
    image_width, image_height = image.size
    y_text = text_start_height
    lines = textwrap.wrap(text, width=40)
    for line in lines:
        line_width, line_height = font.getsize(line)
        draw.text(((image_width - line_width) / 2, y_text), 
                  line, font=font, fill=text_color)
        y_text += line_height


def main():
    '''
    Testing draw_multiple_line_text
    '''
    #image_width
    image = Image.new('RGB', (800, 600), color = (0, 0, 0))
    fontsize = 40  # starting font size
    font = ImageFont.truetype("arial.ttf", fontsize)
    text1 = "I try to add text at the bottom of image and actually I've done it, but in case of my text is longer then image width it is cut from both sides, to simplify I would like text to be in multiple lines if it is longer than image width."
    text2 = "You could use textwrap.wrap to break text into a list of strings, each at most width characters long"

    text_color = (200, 200, 200)
    text_start_height = 0
    draw_multiple_line_text(image, text1, font, text_color, text_start_height)
    draw_multiple_line_text(image, text2, font, text_color, 400)
    image.save('pil_text.png')

if __name__ == "__main__":
    main()
    #cProfile.run('main()') # if you want to do some profiling

结果：

Answer 7

这个函数会将text分割成最多为max长度的行，当字体为font时，它会创建一个带有文本的透明图像。

def split_text(text, font, max)
    text=text.split(" ")
    total=0
    result=[]
    line=""
    for part in text:
        if total+font.getsize(f"{part} ")[0]<max:
            line+=f"{part} "
            total+=font.getsize(part)[0]
        else:
            line=line.rstrip()
            result.append(line)
            line=f"{part} "
            total=font.getsize(f"{part} ")[0]
    line=line.rstrip()
    result.append(line)
    image=new("RGBA", (max, font.getsize("gL")[1]*len(result)), (0, 0, 0, 0))
    imageDrawable=Draw(image)
    position=0
    for line in result:
        imageDrawable.text((0, position), line, font)
        position+=font.getsize("gL")[1]
    return image