Initial commit

lab6-steganography/modes/analyze_quality.py

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+from __future__ import annotations
+from dataclasses import dataclass
+from typing import Dict, List
+import numpy as np
+
+from entities.rgb_image512 import RgbImage512
+from entities.color_space import ColorSpace
+from entities.psnr_metric import PsnrMetric
+
+
+@dataclass
+class AnalyzeQuality:
+    """CLI-режим расчёта метрик качества."""
+
+    def run(
+        self,
+        original_path: str,
+        stego_path: str,
+        space: str = "ycbcr",
+        metrics: List[str] = None,
+    ) -> Dict[str, float]:
+        """Посчитать метрики между изображениями."""
+        if metrics is None:
+            metrics = ["psnr"]
+        metrics = [m.lower() for m in metrics]
+        if any(m != "psnr" for m in metrics):
+            raise ValueError("Поддерживается только метрика PSNR.")
+
+        orig = RgbImage512.from_file(original_path).to_array()
+        steg = RgbImage512.from_file(stego_path).to_array()
+
+        if space.lower() == "ycbcr":
+            a = ColorSpace.rgb_to_ycbcr(orig)
+            b = ColorSpace.rgb_to_ycbcr(steg)
+        elif space.lower() == "rgb":
+            a, b = orig, steg
+        else:
+            raise ValueError("space должен быть 'rgb' или 'ycbcr'.")
+
+        psnr = PsnrMetric().psnr(a, b)
+        return {"psnr": float(psnr)}