WebpImageField for Django

webp_image_field.py

from io import BytesIO
from django.db.models.fields.files import ImageField
from PIL import Image

"""
This field will automatically convert your jpg/png files to webp
Usage:
Replace your ImageField with this one.
Parameters:
webp_quality: Integer, 0-100, Defaults to 80. For lossy, 0 gives the smallest size and 100 the largest. 
For lossless, this parameter is the amount of effort put into the compression: 
0 is the fastest, but gives larger files compared to the slowest, but best, 100.
webp_lossless: if present and true, instructs the WebP writer to use lossless compression.
webp_method: Quality/speed trade-off (0=fast, 6=slower-better). Defaults to 4.
"""

class WebPImageField(ImageField):
    def __init__(self, verbose_name=None, name=None, width_field=None, height_field=None, **kwargs):
      self.webp_quality = kwargs.pop('webp_quality', 80)
      self.webp_lossless = kwargs.pop('webp_lossless', False)
      self.webp_method = kwargs.pop('webp_method', 4)
      super(WebPImageField, self).__init__(verbose_name, name, width_field, height_field, **kwargs)

    def save_form_data(self, instance, data):
        if data:
            image = Image.open(data)
            image = image.convert("RGB")

            webp_image_name = f"{data.name.rsplit('.', 1)[0]}.webp"
            webp_image_bytes = BytesIO()
            image.save(
                webp_image_bytes,
                "WEBP",
                quality=self.webp_quality,
                lossless=self.webp_lossless,
                method=self.webp_method
            )
            webp_image_bytes.seek(0)

            data.file = webp_image_bytes
            data.name = webp_image_name

        super().save_form_data(instance, data)