47 lines
1.8 KiB
Python
47 lines
1.8 KiB
Python
from PIL import Image, ImageDraw
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from pathlib import Path
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def create_soft_edge_mask(width: int, height: int, transition_ratio: float = 0.02) -> Image:
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transition_height = int(height * transition_ratio)
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mask = Image.new("L", (width, height), 255) # 默认全白（不透明）
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draw = ImageDraw.Draw(mask)
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draw.rectangle([0, 0, width, height // 2 - transition_height // 2], fill=0) # 上半黑
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draw.rectangle([0, height // 2 + transition_height // 2, width, height], fill=255) # 下半白
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# 顶部和底部之间 2% 的区域渐变
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for i in range(transition_height):
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alpha = int(255 * (i / transition_height))
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y = height // 2 - transition_height // 2 + i
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draw.line([(0, y), (width, y)], fill=alpha)
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return mask
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def process_image(input_path: str | Path, output_path: str | Path):
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base_width, base_height = 800, 1000
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original = Image.open(input_path).convert("RGBA")
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# 缩放图像宽度适配底图宽度
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scale_ratio = base_width / original.width
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new_height = int(original.height * scale_ratio)
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resized = original.resize((base_width, new_height), Image.LANCZOS)
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# 创建底图并粘贴第一个图像（对齐顶部）
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base_image = Image.new("RGBA", (base_width, base_height), "white")
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base_image.paste(resized, (0, 0), resized)
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# 创建 A2 图层（对齐底部）
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A2 = resized.copy()
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A2_image = Image.new("RGBA", (base_width, base_height), (0, 0, 0, 0))
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A2_y = base_height - A2.height
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A2_image.paste(A2, (0, A2_y), A2)
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# 创建遮罩并加为 alpha 通道
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mask = create_soft_edge_mask(base_width, base_height, 0.02)
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A2_image.putalpha(mask)
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# 合成
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final = Image.alpha_composite(base_image, A2_image)
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final.convert("RGB").save(output_path, format="PNG")
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