diff --git a/Photo.py b/Photo.py
index e64fe85..ae5dd7f 100644
--- a/Photo.py
+++ b/Photo.py
@@ -26,9 +26,9 @@ class Photo:
     def vertical_mirror(self):
         self.img = cv2.flip(self.img, 0, dst=None)
 
-    # ratio: [1%, 500%]
+    # ratio: [1, 500]
     def resize(self, ratio):
-        self.img = cv2.resize(self.img, dsize=None, fx=ratio, fy=ratio, interpolation=cv2.INTER_LINEAR)
+        self.img = cv2.resize(self.img, dsize=None, fx=ratio / 100.0, fy=ratio / 100.0, interpolation=cv2.INTER_LINEAR)
 
     # value: [0,100]
     def lighting(self, value):
@@ -40,45 +40,39 @@ class Photo:
 
     # value: [-100,100]
     def contrast(self, value):
-        hsv = cv2.cvtColor(self.img, cv2.COLOR_BGR2HSV)
-        v = hsv[:, :, 2]
-        avg = 0
-        rows, cols, depth = hsv.shape
-        for r in range(0, rows):
-            for c in range(0, cols):
-                avg += v[r, c]
-        avg /= rows * cols
-        table = []
-        for i in range(0, avg):
-            table.append(-np.power((avg - i) / avg, value) * avg + avg)
-        for i in range(avg + 1, 255):
-            table.append(np.power((i - avg) / (255.0 - avg), value) * (255.0 - avg) + avg)
-        table = np.round(np.array(table)).astype(np.uint8)
-        hsv[:, :, 2] = cv2.LUT(v, table)
-        self.img = cv2.cvtColor(hsv, cv2.COLOR_HSV2BGR)
+        lst = value * self.img
+        lst += np.mean(self.img - lst)
+        np.clip(lst, 0, 255, self.img)
 
-    # value: [-100,100]
 
-    def saturate(self, value):
-        pass
+# value: [-100,100]
 
-    # value: [-100,100]
-    def hue(self, value):
-        pass
+def saturate(self, value):
+    pass
 
-    # value: [0,100]
-    def sharpen(self, value):
-        pass
 
-    # value: [0,100]
-    def blur(self, value):
-        pass
+# value: [-100,100]
+def hue(self, value):
+    pass
+
+
+# value: [0,100]
+def sharpen(self, value):
+    pass
+
+
+# value: [0,100]
+def blur(self, value):
+    pass
+
+
+def toGray(self):
+    pass
+
 
-    def toGray(self):
-        pass
+def invert(self):
+    pass
 
-    def invert(self):
-        pass
 
-    def toBinary(self):
-        pass
+def toBinary(self):
+    pass
diff --git a/test/photo_test.py b/test/photo_test.py
index 05453ea..2714929 100644
--- a/test/photo_test.py
+++ b/test/photo_test.py
@@ -3,7 +3,7 @@ from Photo import Photo
 
 # 读入图片
 photo = Photo("bear.jpg")
-photo.contrast(1.1)
+photo.contrast(0.1)
 cv2.imshow("photo", photo.image())
 
 cv2.waitKey()