75 lines
2.7 KiB
Python
75 lines
2.7 KiB
Python
from PIL import Image
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import os
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from config import Config
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from logger import logger
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class ImageProcessor:
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# 格式映射：将常见的小写格式名转换为 Pillow 可识别的格式名
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FORMAT_MAP = {
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'jpg': 'JPEG',
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'jpeg': 'JPEG',
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'png': 'PNG',
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'webp': 'WEBP',
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'gif': 'GIF',
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'bmp': 'BMP',
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'tiff': 'TIFF',
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}
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@staticmethod
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def resize_by_ratio(img, ratio_width, ratio_height):
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"""等比例缩放至目标比例（最长边适配）"""
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w, h = img.size
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target_ratio = ratio_width / ratio_height
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current_ratio = w / h
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if current_ratio > target_ratio:
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new_w = int(h * target_ratio)
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new_h = h
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else:
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new_w = w
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new_h = int(w / target_ratio)
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return img.resize((new_w, new_h), Image.Resampling.LANCZOS)
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@staticmethod
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def resize_by_pixel(img, target_width, target_height):
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"""等比例缩放至不超过目标像素（保持比例，以较长边为准）"""
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w, h = img.size
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ratio_w = target_width / w
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ratio_h = target_height / h
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ratio = min(ratio_w, ratio_h)
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new_w = int(w * ratio)
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new_h = int(h * ratio)
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return img.resize((new_w, new_h), Image.Resampling.LANCZOS)
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@staticmethod
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def convert_image(input_path, output_path, target_format, quality=None):
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"""
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转换图片格式
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target_format: 小写字符串，如 'jpg', 'png', 'webp'
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"""
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try:
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with Image.open(input_path) as img:
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# 获取 Pillow 标准格式名
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pillow_format = ImageProcessor.FORMAT_MAP.get(target_format.lower())
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if pillow_format is None:
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logger.error(f"不支持的输出格式: {target_format}")
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return False
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# 对于 JPEG 格式，需要处理透明通道
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if pillow_format == 'JPEG' and img.mode in ('RGBA', 'P'):
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rgb_img = Image.new('RGB', img.size, (255, 255, 255))
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rgb_img.paste(img, mask=img.split()[-1] if img.mode == 'RGBA' else None)
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img = rgb_img
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save_kwargs = {}
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if pillow_format in ('JPEG', 'WEBP'):
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save_kwargs['quality'] = quality if quality is not None else Config.DEFAULT_QUALITY
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elif pillow_format == 'PNG':
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save_kwargs['compress_level'] = 6
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img.save(output_path, format=pillow_format, **save_kwargs)
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logger.info(f"转换成功: {input_path} -> {output_path}")
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return True
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except Exception as e:
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logger.error(f"转换失败 {input_path}: {e}")
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return False
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