Python Pillow实现文字转便签图片：从基础到性能优化

from PIL import Image, ImageDraw, ImageFont
# get an image
base = Image.open('Pillow/Tests/images/hopper.png').convert('RGBA')

# make a blank image for the text, initialized to transparent text color
txt = Image.new('RGBA', base.size, (255,255,255,0))

# get a font
fnt = ImageFont.truetype('Pillow/Tests/fonts/FreeMono.ttf', 40)
# get a drawing context
d = ImageDraw.Draw(txt)

# draw text, half opacity
d.text((10,10), "Hello", font=fnt, fill=(255,255,255,128))
# draw text, full opacity
d.text((10,60), "World", font=fnt, fill=(255,255,255,255))

out = Image.alpha_composite(base, txt)

out.show()

def get_paragraph(text, note_width):
 # 把每段文字按约定宽度分隔成几行
 txt = Image.new('RGBA', (100, 100), (255, 255, 255, 0))
 # get a drawing context
 draw = ImageDraw.Draw(txt)
 paragraph, sum_width = '', 0
 line_numbers, line_height = 1, 0
 for char in text:
 w, h = draw.textsize(char, font)
 sum_width += w
 if sum_width > note_width:
  line_numbers += 1
  sum_width = 0
  paragraph += '\n'
 paragraph += char
 line_height = max(h, line_height)
 if not paragraph.endswith('\n'):
 paragraph += '\n'
 return paragraph, line_height, line_numbers


def split_text(text):
 # 将文本按规定宽度分组
 max_line_height, total_lines = 0, 0
 paragraphs = []
 for t in text.split('\n'):
 # 先按 \n 把文本分段
 paragraph, line_height, line_numbers = get_paragraph(t)
 max_line_height = max(line_height, max_line_height)
 total_lines += line_numbers
 paragraphs.append((paragraph, line_numbers))
 line_height = max_line_height
 total_height = total_lines * line_height
 # 这里返回分好的段，文本总高度以及行高
 return paragraphs, total_height, line_height

NOTE_HEADER_IMG = path.normpath(path.join(
 path.dirname(__file__), 'note_header_660.png'))
NOTE_BODY_IMG = path.normpath(path.join(
 path.dirname(__file__), 'note_body_660.png'))
NOTE_FOOTER_IMG = path.normpath(path.join(
 path.dirname(__file__), 'note_footer_660.png'))
NOTE_WIDTH = 660
NOTE_TEXT_WIDTH = 460
body_height = NOTE_BODY_HEIGHT = 206
header_height = NOTE_HEADER_HEIGHT = 89
footer_height = NOTE_FOOTER_HEIGHT = 145
font = ImageFont.truetype(NOTE_OTF, 24)


def get_images(note_height):
 numbers = note_height // body_height + 1
 images = [(NOTE_HEADER_IMG, header_height)]
 images.extend([(NOTE_BODY_IMG, body_height)] * numbers)
 images.append((NOTE_FOOTER_IMG, footer_height))
 return images


def make_backgroud():
 # 将图片拼接到一起
 images = get_images()
 total_height = sum([height for _, height in images])
 # 最终拼接完成后的图片
 backgroud = Image.new('RGB', (body_width, total_height))
 left, right = 0, 0
 background_img = '/tmp/%s_backgroud.png' % total_height
 # 判断背景图是否存在
 if path.exists(background_img):
 return background_img
 for image_file, height in images:
 image = Image.open(image_file)
 # (0, left, self.body_width, right+height)
 # 分别为 左上角坐标 0, left
 # 右下角坐标 self.body_width, right+height
 backgroud.paste(image, (0, left, body_width, right+height))
 left += height # 从上往下拼接，左上角的纵坐标递增
 right += height # 左下角的纵坐标也递增
 backgroud.save(background_img, quality=85)
 return background_img

def draw_text(paragraphs, height):
 background_img = make_backgroud()
 note_img = Image.open(background_img).convert("RGBA")
 draw = ImageDraw.Draw(note_img)
 # 文字开始位置坐标，需要根据背景图的大小做调整
 x, y = 80, 100
 for paragraph, line_numbers in paragraphs:
 for line in paragraph.split('\n')[:-1]:
  draw.text((x, y), line, fill=(110, 99, 87), font=font)
  y += line_height
 # draw.text((x, y), paragraph, fill=(110, 99, 87), font=font)
 # y += self.line_height * line_numbers
 note_img.save(filename, "png", quality=1, optimize=True)
 return filename

note_img.save(filename, "png", quality=1, optimize=True)