| """Business logic services.""" |
|
|
| import io |
| import logging |
|
|
| from PIL import Image |
|
|
| logger = logging.getLogger(__name__) |
|
|
|
|
| def apply_rotation_for_pdf(image_bytes: bytes, rotation: int) -> bytes: |
| if rotation not in (0, 90, 180, 270): |
| rotation = 0 |
|
|
| if rotation == 0: |
| try: |
| img: Image.Image = Image.open(io.BytesIO(image_bytes)) |
| if img.format == "JPEG": |
| return image_bytes |
| output = io.BytesIO() |
| img = _ensure_rgb(img) |
| img.save(output, format="JPEG", quality=85, optimize=True) |
| return output.getvalue() |
| except Exception: |
| logger.exception("操作失败") |
|
|
| return image_bytes |
|
|
| try: |
| img2: Image.Image = Image.open(io.BytesIO(image_bytes)) |
| pillow_angle = (360 - rotation) % 360 |
| if pillow_angle != 0: |
| img2 = img2.rotate(pillow_angle, expand=True) |
|
|
| output = io.BytesIO() |
| img2 = _ensure_rgb(img2) |
| img2.save(output, format="JPEG", quality=85, optimize=True) |
| return output.getvalue() |
| except Exception as e: |
| logger.warning(f"图片旋转失败,使用原始图片: {e}") |
| return image_bytes |
|
|
|
|
| def _ensure_rgb(img: Image.Image) -> Image.Image: |
| if img.mode in ("RGBA", "P"): |
| background = Image.new("RGB", img.size, (255, 255, 255)) |
| if img.mode == "RGBA": |
| background.paste(img, mask=img.split()[3]) |
| else: |
| background.paste(img) |
| return background |
| if img.mode != "RGB": |
| return img.convert("RGB") |
| return img |
|
|
