def __init__(
self,
vocab: str,
num_samples: int,
cache_samples: bool = False,
font_family: Optional[Union[str, List[str]]] = None,
img_transforms: Optional[Callable[[Any], Any]] = None,
sample_transforms: Optional[Callable[[Any, Any], Tuple[Any,
Any]]] = None,
) -> None:
self.vocab = vocab
self._num_samples = num_samples
self.font_family = font_family if isinstance(
font_family, list) else [font_family] # type: ignore[list-item]
# Validate fonts
if isinstance(font_family, list):
for font in self.font_family:
try:
_ = get_font(font, 10)
except OSError:
raise ValueError(f"unable to locate font: {font}")
self.img_transforms = img_transforms
self.sample_transforms = sample_transforms
self._data: List[Image.Image] = []
if cache_samples:
self._data = [(synthesize_text_img(char, font_family=font), idx)
for idx, char in enumerate(self.vocab)
for font in self.font_family]
def synthesize_text_img(
text: str,
font_size: int = 32,
font_family: Optional[str] = None,
background_color: Optional[Tuple[int, int, int]] = None,
text_color: Optional[Tuple[int, int, int]] = None,
) -> Image:
"""Generate a synthetic text image
Args:
text: the text to render as an image
font_size: the size of the font
font_family: the font family (has to be installed on your system)
background_color: background color of the final image
text_color: text color on the final image
Returns:
PIL image of the text
"""
background_color = (0, 0,
0) if background_color is None else background_color
text_color = (255, 255, 255) if text_color is None else text_color
font = get_font(font_family, font_size)
text_w, text_h = font.getsize(text)
h, w = int(round(1.3 * text_h)), int(round(1.1 * text_w))
# If single letter, make the image square, otherwise expand to meet the text size
img_size = (h, w) if len(text) > 1 else (max(h, w), max(h, w))
img = Image.new("RGB", img_size[::-1], color=background_color)
d = ImageDraw.Draw(img)
# Offset so that the text is centered
text_pos = (int(round(
(img_size[1] - text_w) / 2)), int(round((img_size[0] - text_h) / 2)))
# Draw the text
d.text(text_pos, text, font=font, fill=text_color)
return img
def __init__(
self,
vocab: str,
min_chars: int,
max_chars: int,
num_samples: int,
cache_samples: bool = False,
font_family: Optional[Union[str, List[str]]] = None,
img_transforms: Optional[Callable[[Any], Any]] = None,
sample_transforms: Optional[Callable[[Any, Any], Tuple[Any,
Any]]] = None,
) -> None:
self.vocab = vocab
self.wordlen_range = (min_chars, max_chars)
self._num_samples = num_samples
self.font_family = font_family if isinstance(
font_family, list) else [font_family] # type: ignore[list-item]
# Validate fonts
if isinstance(font_family, list):
for font in self.font_family:
try:
_ = get_font(font, 10)
except OSError:
raise ValueError(f"unable to locate font: {font}")
self.img_transforms = img_transforms
self.sample_transforms = sample_transforms
self._data: List[Image.Image] = []
if cache_samples:
_words = [
self._generate_string(*self.wordlen_range)
for _ in range(num_samples)
]
self._data = [(synthesize_text_img(text,
font_family=random.choice(
self.font_family)), text)
for text in _words]
def test_get_font():
# Attempts to load recommended OS font
font = get_font()
assert isinstance(font, (ImageFont, FreeTypeFont))