diff --git a/3/1.py b/3/1.py
new file mode 100644
index 0000000..d2e9dbd
--- /dev/null
+++ b/3/1.py
@@ -0,0 +1,15 @@
+import numpy as np
+import pywt
+
+data = np.array([22, 26, 30, 18, 16, 20, 25, 36])
+coeffs0 = pywt.dwt(data, "haar")
+coeffs1 = pywt.wavedec(data, "haar", level=2)
+
+data1 = np.array([[12, 4, 26, 14], [6, 27, 32, 22], [18, 12, 30, 24], [32, 28, 10, 8]])
+coeffs2 = pywt.dwt2(data1, "haar")
+coeffs3 = pywt.wavedec2(data1, "haar", level=2)
+
+print(coeffs0)
+print(coeffs1)
+print(coeffs2)
+print(coeffs3)
diff --git a/3/2.py b/3/2.py
new file mode 100644
index 0000000..dcc650a
--- /dev/null
+++ b/3/2.py
@@ -0,0 +1,21 @@
+import cv2 as cv
+import numpy as np
+import pywt
+from matplotlib import pyplot as plt
+
+img = cv.imread("images/house.jpg")
+img = cv.resize(img, (512, 512))
+img = cv.cvtColor(img, cv.COLOR_BGR2GRAY).astype(np.float32)
+
+plt.figure("二维小波一级变换")
+coeffs = pywt.dwt2(img, "haar")
+cA, (cH, cV, cD) = coeffs
+
+AH = np.concatenate([cA, cH], axis=1)
+VD = np.concatenate([cV, cD], axis=1)
+img1 = np.concatenate([AH, VD], axis=0)
+
+plt.imshow(img1, cmap="gray")
+plt.title("result")
+plt.axis("off")
+plt.show()
diff --git a/3/3.py b/3/3.py
new file mode 100644
index 0000000..5b6d9a5
--- /dev/null
+++ b/3/3.py
@@ -0,0 +1,25 @@
+import cv2 as cv
+import matplotlib.pyplot as plt
+import numpy as np
+import pywt
+
+img = cv.imread("images/house.jpg")
+img = cv.resize(img, (512, 512))
+img = cv.cvtColor(img, cv.COLOR_BGR2GRAY).astype(np.float32)
+
+plt.figure("二维图像多级分解")
+coeffs = pywt.wavedec2(img, "haar", level=2)
+cA2, (cH2, cV2, cD2), (cH1, cV1, cD1) = coeffs
+
+AH2 = np.concatenate([cA2, cH2 + 510], axis=1)
+VD2 = np.concatenate([cV2 + 510, cD2 + 510], axis=1)
+cA1 = np.concatenate([AH2, VD2], axis=0)
+
+AH = np.concatenate([cA1, (cH1 + 255) * 2], axis=1)
+VD = np.concatenate([(cV1 + 255) * 2, (cD1 + 255) * 2], axis=1)
+img = np.concatenate([AH, VD], axis=0)
+
+plt.imshow(img, cmap="gray")
+plt.title("2D WT")
+plt.axis("off")
+plt.show()