完善图片压缩功能

.gitignore

@@ -0,0 +1,5 @@
+venv/
+input/
+output/
+__pycache__/
+

README.md

@@ -4,6 +4,7 @@
 
 #### v260717补丁
 1. 修改图片压缩文件名
+2. 完善图片压缩功能
 
 #### v260717
 1. 新增JS音乐播放器（基于Meting-API）

image-compression.py

@@ -3,118 +3,119 @@ from PIL import Image
 import os
 import shutil
 
-def get_file_kb(file_path: str) -> float:
+SUPPORTED_OUTPUT_FORMATS = ("jpg", "jpeg", "png", "webp")
-    """获取文件大小 KB"""
-    size_byte = os.path.getsize(file_path)
-    return size_byte / 1024
 
-def compress_to_jpg_loop(
+
-    input_path: str,
+def get_file_kb(file_path: str) -> float:
-    output_path: str,
+    return os.path.getsize(file_path) / 1024
-    min_size_kb: float,
+
-    max_size_kb: float,
+
-    init_quality: int,
+def _save_image(img: Image.Image, output_path: str, output_format: str, quality: int):
-    quality_step: int,
+    if output_format == "png":
-    min_quality: int,
+        img.save(output_path, format="PNG", optimize=True, compress_level=9)
-    max_width: int,
+    elif output_format == "webp":
-    max_height: int
+        img.save(output_path, format="WEBP", quality=quality, method=6)
-):
+    else:
+        img.save(output_path, format="JPEG", quality=quality, optimize=True)
+
+
+def compress_to_format_loop(input_path, output_path, min_size_kb, max_size_kb,
+                            init_quality, quality_step, min_quality,
+                            max_width, max_height, output_format):
     try:
+        # None 表示保持输入图片格式。
+        if output_format is None:
+            output_format = os.path.splitext(input_path)[1].lower().lstrip(".")
+        output_format = output_format.lower().lstrip(".")
+        if output_format not in SUPPORTED_OUTPUT_FORMATS:
+            raise ValueError(f"不支持的输出格式: {output_format}")
+
         ori_size = get_file_kb(input_path)
         print(f"\n原图: {os.path.basename(input_path)} | 大小: {ori_size:.2f} KB")
 
-        # 小于阈值，直接复制原图，不压缩
+        # INIT_QUALITY=None：不压缩、不缩放；目标格式不同则只做格式转换。
-        if ori_size < min_size_kb:
+        # 小于阈值：同样不压缩、不缩放；目标格式不同则只做格式转换。
-            shutil.copy2(input_path, output_path)
+        if init_quality is None or ori_size < min_size_kb:
-            print(f"✅ 小于{min_size_kb}KB，无需压缩，直接复制")
+            if os.path.splitext(input_path)[1].lower().lstrip(".") == output_format:
+                shutil.copy2(input_path, output_path)
+                print(f"✅ 小于{min_size_kb}KB，无需压缩，直接复制")
+            else:
+                img = Image.open(input_path)
+                img = _prepare_image(img, output_format)
+                _save_image(img, output_path, output_format, init_quality)
+                reason = "INIT_QUALITY=None" if init_quality is None else f"小于{min_size_kb}KB"
+                print(f"✅ {reason}，不压缩，仅转换为 {output_format}")
             return
 
-        # 打开图片，处理透明通道
         img = Image.open(input_path)
-        if img.mode in ("RGBA", "P"):
+        img = _prepare_image(img, output_format)
-            new_img = Image.new("RGB", img.size, (255, 255, 255))
-            mask = img.split()[-1] if img.mode == "RGBA" else None
-            new_img.paste(img, mask=mask)
-            img = new_img
-
-        # 等比例缩放
         if max_width and max_height:
             img.thumbnail((max_width, max_height))
 
-        current_quality = init_quality
+        # PNG 没有 quality 参数，直接用最高无损压缩保存。
+        if output_format == "png":
+            _save_image(img, output_path, output_format, init_quality)
+            print(f"✅ PNG 已保存 | 输出大小: {get_file_kb(output_path):.2f} KB")
+            return
+
+        quality = init_quality
         while True:
-            img.save(output_path, format="JPEG", quality=current_quality, optimize=True)
+            _save_image(img, output_path, output_format, quality)
             out_size = get_file_kb(output_path)
-
+            if out_size <= max_size_kb or quality <= min_quality:
-            if out_size <= max_size_kb or current_quality <= min_quality:
+                print(f"✅ 最终画质 {quality} | 输出大小: {out_size:.2f} KB")
-                print(f"✅ 最终画质 {current_quality} | 输出大小: {out_size:.2f} KB")
                 break
-
+            quality = max(min_quality, quality - quality_step)
-            current_quality -= quality_step
+            print(f"⚠️ {out_size:.2f}KB > {max_size_kb}KB，降低画质至 {quality} 重新压缩")
-            print(f"⚠️ {out_size:.2f}KB > {max_size_kb}KB，降低画质至 {current_quality} 重新压缩")
-
     except Exception as e:
         print(f"❌ 处理失败 {input_path}：{str(e)}")
 
 
-def batch_compress_folder(
+def _prepare_image(img, output_format):
-    input_dir: str,
+    has_alpha = "A" in img.getbands() or (img.mode == "P" and "transparency" in img.info)
-    output_dir: str,
+    if output_format in ("jpg", "jpeg"):
-    min_kb,
+        if has_alpha:
-    max_kb,
+            rgba = img.convert("RGBA")
-    init_q,
+            result = Image.new("RGB", rgba.size, (255, 255, 255))
-    q_step,
+            result.paste(rgba, mask=rgba.getchannel("A"))
-    min_q,
+            return result
-    max_w,
+        return img.convert("RGB")
-    max_h
+    return img.convert("RGBA" if has_alpha else "RGB")
-):
+
+
+def batch_compress_folder(input_dir, output_dir, min_kb, max_kb, init_q,
+                          q_step, min_q, max_w, max_h, output_format):
     os.makedirs(output_dir, exist_ok=True)
     support_ext = (".png", ".jpg", ".jpeg", ".webp", ".bmp")
-
     for filename in os.listdir(input_dir):
         file_path = os.path.join(input_dir, filename)
-        if not filename.lower().endswith(support_ext):
+        if os.path.isdir(file_path) or not filename.lower().endswith(support_ext):
             continue
-        if os.path.isdir(file_path):
-            continue
-
         name_no_ext = os.path.splitext(filename)[0]
-        out_file = os.path.join(output_dir, f"{name_no_ext}.jpg")
+        suffix = output_format or os.path.splitext(filename)[1].lstrip(".")
-        compress_to_jpg_loop(
+        out_file = os.path.join(output_dir, f"{name_no_ext}.{suffix}")
-            input_path=file_path,
+        compress_to_format_loop(file_path, out_file, min_kb, max_kb, init_q,
-            output_path=out_file,
+                                q_step, min_q, max_w, max_h, output_format)
-            min_size_kb=min_kb,
-            max_size_kb=max_kb,
-            init_quality=init_q,
-            quality_step=q_step,
-            min_quality=min_q,
-            max_width=max_w,
-            max_height=max_h
-        )
 
 
 if __name__ == "__main__":
-    # ==================== 批量配置区（仅需修改这里） ====================
+    # 输入输出文件夹
     INPUT_FOLDER = "./input"
     OUTPUT_FOLDER = "./output"
-    MIN_SIZE_KB = 200      # 小于该KB不压缩
+    # 首次压缩质量，不压缩填 None
-    MAX_SIZE_KB = 800      # 超过该KB循环再压
+    INIT_QUALITY = 75
-    INIT_QUALITY = 75      # 初始画质
+    # 过小不压缩，过大重复压缩
-    QUALITY_STEP = 8       # 每次降低画质数值
+    MIN_SIZE_KB = 100
-    MIN_QUALITY = 20       # 最低画质底线
+    MAX_SIZE_KB = 500
-    LIMIT_W = 2560         # 不需要缩放填 None
+    # 重复压缩质量递减及最小值
+    QUALITY_STEP = 8
+    MIN_QUALITY = 20
+    # 更换格式，不转换格式填 None
+    OUTPUT_FORMAT = "webp"
+    # 尺寸压缩，不缩放填 None
+    LIMIT_W = 2560
     LIMIT_H = 1440
-    # ==================================================================
 
-    # 仅批量执行，无任何单张代码
+    batch_compress_folder(INPUT_FOLDER, OUTPUT_FOLDER, MIN_SIZE_KB, MAX_SIZE_KB,
-    batch_compress_folder(
+                          INIT_QUALITY, QUALITY_STEP, MIN_QUALITY, LIMIT_W,
-        input_dir=INPUT_FOLDER,
+                          LIMIT_H, OUTPUT_FORMAT)
-        output_dir=OUTPUT_FOLDER,
-        min_kb=MIN_SIZE_KB,
-        max_kb=MAX_SIZE_KB,
-        init_q=INIT_QUALITY,
-        q_step=QUALITY_STEP,
-        min_q=MIN_QUALITY,
-        max_w=LIMIT_W,
-        max_h=LIMIT_H
-    )